ORIGINAL RESEARCH Open Access

Large-scale wildfire reduces populationgrowth in a peripheral population of sage-grouseIan F Dudley123 Peter S Coates1 Brian G Prochazka1 Shawn T OrsquoNeil1 Scott Gardner3 and David J Delehanty2

Abstract

Background Drastic increases in wildfire size and frequency threaten western North American sagebrush (ArtemisiaL spp) ecosystems At relatively large spatial scales wildfire facilitates type conversion of sagebrush-dominatedplant communities to monocultures of invasive annual grasses (eg Bromus tectorum L) Annual grasses providefine fuels that promote fire spread contributing to a positive grassndashfire feedback cycle that affects most sagebrushecosystems with expected habitat loss for resident wildlife populations Greater sage-grouse (Centrocercusurophasianus Bonaparte 1827) are sagebrush obligate species that are indicators of sagebrush ecosystem functionbecause they rely on different components of sagebrush ecosystems to meet seasonal life history needs Becausewildfire cannot be predicted chronic impacts of wildfire on sage-grouse populations have been largely limited tocorrelative studies Thus evidence from well-designed experiments is needed to understand the specificmechanisms by which wildfire is detrimental to sage-grouse population dynamics

Results Following a significant wildfire event in the southwest periphery of sage-grouse range we implemented abefore-after-control-impact study with long-term paired (BACIP) datasets of male sage-grouse surveyed fromtraditional breeding grounds (leks) within and outside the wildfire boundary We estimated sage-grouse populationrate of change in apparent abundance (λ) at burned and unburned areas before and after wildfire and derived

BACIP ratios which provide controlled evidence of wildfire impact We found that λ at leks within the wildfireboundary decreased approximately 16 relative to leks at control sites Furthermore we estimated a 985

probability that the observed change in λ could be attributed to the wildfire

Conclusions We demonstrated adverse wildfire impacts on sage-grouse population growth using an experimentalBACIP design which disentangled the effect of wildfire disturbance from natural population fluctuations Our resultsunderscore the importance of active and comprehensive management actions immediately following wildfire (ieseeding coupled with planting sagebrush) that might offset short-term impacts of wildfire by timing rapid recoveryof sagebrush to meet short-term speciesrsquo habitat requirements Burned leks likely have substantial immediateimpacts that may extend beyond wildfire boundaries especially if critical source habitats are removed Suchimpacts could fragment habitat and disrupt connectivity thereby affecting larger populations and possiblycontributing to more widespread declines in sage-grouse populations

Keywords BACI design Centrocercus urophasianus cheatgrass sagebrush obligate sage-grouse umbrella specieswildfire

copy The Author(s) 2021 Open Access This article is licensed under a Creative Commons Attribution 40 International Licensewhich permits use sharing adaptation distribution and reproduction in any medium or format as long as you giveappropriate credit to the original author(s) and the source provide a link to the Creative Commons licence and indicate ifchanges were made The images or other third party material in this article are included in the articles Creative Commonslicence unless indicated otherwise in a credit line to the material If material is not included in the articles Creative Commonslicence and your intended use is not permitted by statutory regulation or exceeds the permitted use you will need to obtainpermission directly from the copyright holder To view a copy of this licence visit httpcreativecommonsorglicensesby40

Correspondence pcoatesusgsgov1US Geological Survey Western Ecological Research Center Dixon FieldStation 800 Business Park Drive Suite D Dixon California 95620 USAFull list of author information is available at the end of the article

Fire EcologyDudley et al Fire Ecology (2021) 1715 httpsdoiorg101186s42408-021-00099-z

Resumen

Antecedentes Incrementos draacutesticos en el tamantildeo y frecuencia de incendios amenazan los ecosistemas de artemisia(Artemisia L spp) en Norte Ameacuterica A escalas espaciales relativamente grandes los incendios facilitan la conversioacuten decomunidades dominadas por artemisia en monoculturas de especies de pastos anuales invasores (ie Bromus tectorumL) Estos pastos anuales proveen los combustibles finos que promueven la propagacioacuten del fuego contribuyendo a unciclo de retroalimentacioacuten positiva que afecta la mayoriacutea de los ecosistemas de artemisia con la expectativa de peacuterdidade haacutebitat para las poblaciones residentes de fauna silvestre El urogallo de las artemisas o gallo de salvia (Centrocercusurophasianus Bonaparte 1827) es una especie obligada de los ecosistemas de artemisia indicadora delfuncionamiento de estos ecosistemas dado que dependen de diferentes componentes de esos ecosistemas paracumplir con sus necesidades en su ciclo de vida Dado que los incendios no pueden predecirse los impactos croacutenicosde los incendios sobre las poblaciones del gallo de salvia han sido generalmente limitados a estudios correlativos Laevidencia de experimentos bien disentildeados es entonces necesaria para entender los mecanismos especiacuteficos por loscuales los incendios son perjudiciales para la dinaacutemica poblacional del gallo de salvia

Resultados Luego de un evento de fuego significativo en la periferia sudoeste del haacutebitat del gallo de salviaimplementamos un estudio de impacto (previo-posterior y control de largo plazo) mediante un conjunto de datosapareados (BACIP) de machos del gallo de salvia relevados en lugares de apareo (leks) dentro y fuera del periacutemetro delos incendios Estimamos la tasa de cambio de la poblacioacuten en abundancia aparente (λ) en aacutereas quemadas y noquemadas antes y despueacutes del incendio y derivamos las relaciones BACIP que proveen de una evidencia controlada

del impacto del fuego Encontramos que λ en los lugares de apareo (leks) dentro del periacutemetro del fuego decrecieronaproximadamente un 16 en relacioacuten con los leks en los sitios de control Estimamos ademaacutes que en un 985 de

probabilidad el cambio observado en λ puede ser atribuido al efecto del incendio

Conclusiones Demostramos los efectos adversos del fuego en el crecimiento de las poblaciones del gallo de salviausando el disentildeo experimental BACIP el cual separa los efectos del disturbio fuego de las fluctuaciones naturales de laspoblaciones de este gallo Nuestros resultados subrayan la importancia de acciones de manejo activas y comprensivasinmediatamente posteriores a un evento de fuego (ie sembrado junto con el plantado de artemisia) que puedencompensar los impactos inmediatos del fuego mediante la sincronizacioacuten de una raacutepida recuperacioacuten de artemisia paraalcanzar los requerimientos de haacutebitat de la especie en el corto plazo Los lugares de apareo quemados tienen un impactosustancial inmediato que puede extenderse maacutes allaacute de los liacutemites del incendio especialmente si algunos lugares criacuteticosdel haacutebitat son eliminados Estos impactos pueden fragmentar el haacutebitat e interrumpir la conectividad afectando por lotanto a poblaciones maacutes grandes y contribuyendo a un mayor descenso en las poblaciones del gallo de salvia

AbbreviationsBACI Before-After-Control-Impact analysis designBACIP Before-After-Control-Impact analysis design usingPaired datasetsBLM Bureau of Land ManagementCDFW California Department of Fish and WildlifeCI Control-ImpactCRI CRedible IntervalPMU Population Management UnitQA Quality AssuranceQC Quality ControlSSM State-Space ModelUSFS United States Forest ServiceUSGS United States Geological SurveyWAFWA Western Association of Fish and Wildlife Agencies

BackgroundWildfire frequency has increased throughout westernNorth America with large-scale wildfires becoming in-creasingly common (DrsquoAntonio and Vitousek 1992

Baker 2006 Pechony and Shindell 2010 Pilliod et al2017) In the sagebrush (Artemisia L spp) steppe eco-system of the Great Basin region of the United Statesthis phenomenon has been exacerbated by the spread ofexotic annual grasses such as cheatgrass (Bromus tec-torum L Knapp 1996 Brooks et al 2004 Chamberset al 2014 Brooks et al 2015) and medusahead wildrye(Taeniatherum caput-medusae [L] Nevski Young 1992)Wildfire and annual grass presence interact to form apositive feedback loop by which grass invasion is pro-moted by fires and subsequently senesces early produ-cing continuous fine fuel beds that increase thelikelihood and spread of future wildfire (Miller et al2011 Balch et al 2013 Chambers et al 2014) Afterwildfire the existing sagebrush community is slow toregenerate through natural seed dispersal and manycommon sagebrush species in the Great Basin do not re-sprout (Bunting et al 1987 Beck et al 2009) Thus thisannual grassndashwildfire feedback cycle often results in theelimination of sagebrush on the landscape promoting

Dudley et al Fire Ecology (2021) 1715 Page 2 of 13

replacement by annual grasses (Shultz 2006 Miller et al2013) and subsequently leading to alternative ecosystemstates (Hobbs et al 2006 Shriver et al 2019)The altered wildfire regime and associated state transi-

tions of sagebrush to annual grasses in sagebrush steppeecosystems is a major threat to species such as the greatersage-grouse (Centrocercus urophasianus Bonaparte 1827hereafter sage-grouse Nelle et al 2000 US Fish and Wild-life Service 2015 Coates et al 2016) that require intactsagebrush communities for certain life stages Sage-grousepopulations were predicted to decline to ~43 of theircurrent population size within the next 30 years withinthe Great Basin if the grassndashfire cycle is left unabated(Coates et al 2016) Sage-grouse are a gallinaceous birdspecies with elaborate courtship rituals that exhibit stronglek and site fidelity (Fischer et al 1993 Schroeder andRobb 2003 Connelly et al 2011a) Individuals will oftenreturn to the same breeding area as used in previous yearsand females often nest near previous nest sites (Fischeret al 1993 Schroeder and Robb 2003 ONeil et al 2020)Such behavioral rigidity following disturbance eventscould negatively influence population dynamics (Schroe-der and Robb 2003 Carroll et al 2017) whereby historic-ally beneficial behaviors become maladaptive in an alteredecosystem (Battin 2004 Robertson et al 2013 ONeil et al2020)Prevailing evidence suggests that sage-grouse continue

to occupy burned areas in years immediately followingwildfire instead of seeking out unburned albeit novel al-ternatives (Lockyer et al 2015 Foster et al 2019 Dudley2020 ONeil et al 2020) Wildfire has been known toalter habitat composition (Hess and Beck 2012 Davisand Crawford 2015) and food resources (Rhodes et al2010) and may reduce nest and adult survival (Lockyeret al 2015 Foster et al 2019 Dudley 2020) with poten-tially negative impacts on lek attendance (Steenvoordenet al 2019) This implies that wildfire is likely to haveshort-term negative impacts on sage-grouse populationgrowth and may also reduce long-term habitat popula-tion capacity when permanent state transitions of habitatpatches to annual grass occur (Miller et al 2011)However because multiple stressors may affect popula-tions simultaneously and sage-grouse populations tendto be cyclical (Garton et al 2015 Coates et al 2018Coates et al 2019) it is often difficult to attribute short-term population decline to a single specific causeUnder these circumstances paired study designs thatfacilitate comparisons between affected and unaffectedareas are especially useful for understanding the influ-ence of localized disturbances on populations of conser-vation concern (Conner et al 2016) Within the GreatBasin for example a better understanding of theimpacts of changing wildfire regimes on sage-grousepopulations has become an important resource

management objective (US Fish and Wildlife Service2015 WAFWA 2015 Ricca and Coates 2020)Recent wildfires that burned substantial areas of sage-

brush in northeastern California and northwesternNevada USA have created both opportunity and ur-gency to evaluate short-term impacts on important sage-grouse breeding concentration areas occurring near theperiphery of current sage-grouse distribution In 2012 alarge wildfire (hereafter the Rush Fire) burned approxi-mately 124 000 ha of sagebrush in Lassen CountyCalifornia and Washoe County Nevada (Bureau of LandManagement 2012) an area that supported a breedingpopulation of 1500 to 4500 sage-grouse between 1987and 2003 (Armentrout and Hall 2005) To evaluate theimpact of the Rush Fire on estimated rate of change in

apparent sage-grouse population abundance ( λ ) in thisregion we proposed and implemented a paired study de-

sign contrasting λ within and outside areas that burnedusing sage-grouse lek count data that were recorded be-fore and after a large fire event For wildlife and resourcemanagers the continued use of lek sites by sage-grousefor courtship provides opportunity for annual monitor-ing of sage-grouse populations Lek counts are the mostcommon and cost-effective method for tracking sage-grouse abundance at various spatial scales (Patterson1952 Connelly and Schroeder 2007 Blomberg andHagen 2020) Lek counts were implemented as early asthe 1930s (Johnson and Rowland 2007) so in manycases long-term population trends can be establishedfrom these datasets Lek counts are a direct measure ofmale lek attendance and are generally assumed to trackoverall abundance and population trends (Blomberget al 2013a Monroe et al 2016 Wann et al 2019) Lekcounts have been used to evaluate effects of a variety ofimpacts within the speciesrsquo range stemming from energydevelopment (Green et al 2017) agriculture (Dohertyet al 2016) livestock grazing (Monroe et al 2017) andconifer expansion (Baruch-Mordo et al 2013) as well asprescribed fire (Connelly et al 2000) and wildfire(Coates et al 2016 Steenvoorden et al 2019)The long-term lek count datasets used in our study fa-

cilitated a before-after-control-impact (BACI) analysisdesign using paired datasets (BACIP Stewart-Oatenet al 1986) which are used to make inference about im-pacts of a treatment or disturbance (Queen et al 2002)relative to controls In this case count data collectedfrom leks inside and outside the known fire perimeterprovided a robust BACIP dataset spanning breedingyears prior to and after the Rush Fire (2007 to 2012 and2013 to 2018 respectively) The primary purpose of theBACIP study design is to compare the state of a systemafter the impact of a disturbance to the state of the same

Dudley et al Fire Ecology (2021) 1715 Page 3 of 13

system where the disturbance did not occur while ac-counting for pre-existing spatial heterogeneity and nat-ural temporal change (Green 1979 Stewart-Oaten et al1986 Underwood 1992) Applying a BACI analysis tosage-grouse lek count data provides an empirically basedframework to quantify the effects of this large-scale wild-fire on the population dynamics of a peripheral popula-tion of sage-grouse We hypothesized that populationgrowth rates of leks located inside the Rush Fire perim-eter would be more adversely affected than leks locatedoutside the fire perimeter

MethodsStudy areaOur study took place within the Buffalo-SkedaddlePopulation Management Unit (PMU) in eastern LassenCounty of northeastern California and Washoe Countyin northwestern Nevada (hereinafter Susanville studyarea) The Buffalo-Skedaddle PMU encompasses an areaof approximately 1 172 260 ha The study site which oc-cupied most of the Buffalo-Skedaddle PMU ranged inelevation from 1350 to 2400 m and consisted predomin-antly of public land administered by the Bureau of LandManagement or private lands During the study period(2007 to 2018) the area experienced a mean annual pre-cipitation of 2717 cm (SD = 1411) and a mean annualtemperature of 106 degC (SD = 074 Susanville MunicipalAirport Western Regional Climate Center httpswrccdrieducgi-bincliMAINplca8702) The Rush Fire tookplace in August 2012 (post breeding season) and burnedapproximately 124 000 ha Most of the burn (gt97) oc-curred within the Buffalo-Skedaddle PMU (~18 ofPMU area burned) extending from Skedaddle Mountainto Madeline Plains along the western side of the Califor-niandashNevada state border (Fig 1)Throughout the study area cheatgrass and medusa-

head wildrye were common understory vegetation com-ponents but were more prevalent inside the fireperimeter post-fire (P Coates US Geological SurveyDixon California USA unpublished data) Outside theRush Fire perimeter the plant community was a colddesert shrub steppe dominated big sagebrush (Artemesiatridentata Nutt) dwarf sagebrush (A arbuscula Nutt)and antelope bitterbrush (Purshia tridentata Curran)Silver sagebrush (A cana Pursh) was common in thenorthwest area of the study site The primary land useswere livestock grazing (sheep and cattle) and irrigatedagriculture US Highway 395 and a network of smallerpaved improved gravel and unimproved two-trackroads provided access throughout the study area Thestudy area included 80 sage-grouse leks with 30 consid-ered active (ge2 males observed on at least two separateoccasions during the previous ten years WAFWA 2015)Local breeding abundance estimates for this sub-

population (PMU-level) ranged from 1500 to 4000 indi-viduals between 1987 and 2003 (Armentrout and Hall2005)

Lek countsPersonnel from California Department of Fish and Wild-life (CDFW) Bureau of Land Management (BLM) USForest Service (USFS) and US Geological Survey (USGS)used established protocols (Connelly et al 2003) tocount sage-grouse leks within the Susanville study areafrom early March to late April spanning the period ofpeak lek attendance by males in this region (Wann et al2019) Lek counts were conducted between 30 min be-fore and 90 min after sunrise by ground observers usingbinoculars spotting scopes or both from suitable obser-vation locations Three lek counts were conducted dur-ing a single survey and the highest male count wasrecorded Each lek was counted multiple times duringthe breeding season and the maximum male count wasassumed to represent peak male attendance for each lekfrom 2007 to 2018 All lek count data used for analyseswere obtained from the Western Association of Fish andWildlife Agencies dataset and were subject to QA andQC measures (WAFWA 2015) prior to analysis

To estimate the impact of the Rush Fire on λ we usedcount data from 15 active leks located within the Buffalo-Skedaddle PMU (Fig 1) Leks used in the analysis had tohave an active status within the WAFWA dataset andfewer than five missing counts over the 12-year studyperiod We overlaid leks that met those criteria with wild-fire spatial data collected from the Monitoring Trends inBurn Severity (Eidenshink et al 2007) database andassigned a categorical fire affiliation of inside (n = 6impact) or outside (n = 9 control) based on their locationrelative to the Rush Fire perimeter (Fig 1) Leks locatedoutside the fire perimeter had an average distance of123 km (SD = 84 km) to the nearest fire perimeteredge and ranged from 03 to 270 km outside the fireperimeter Leks located inside the fire perimeter hadan average distance of 47 km (SD = 35 km) to thenearest fire perimeter edge and ranged from 02 to90 km inside the fire perimeter

Modeling approachWe used a statendashspace modeling (hereafter SSM) ap-proach in a Bayesian framework (Royle and Dorazio

2008 Keacutery and Schaub 2011) to estimate λ from lekcount data collected from a population of sage-grousewithin the Susanville study area The advantage of SSMover other methods is that it accounts for observationerror (ε ie detections are imperfect) and it is inher-ently Markovian which was appropriate for these timeseries data We bifurcated the modeling process based

Dudley et al Fire Ecology (2021) 1715 Page 4 of 13

replacement by annual grasses (Shultz 2006 Miller et al2013) and subsequently leading to alternative ecosystemstates (Hobbs et al 2006 Shriver et al 2019)The altered wildfire regime and associated state transi-

tions of sagebrush to annual grasses in sagebrush steppeecosystems is a major threat to species such as the greatersage-grouse (Centrocercus urophasianus Bonaparte 1827hereafter sage-grouse Nelle et al 2000 US Fish and Wild-life Service 2015 Coates et al 2016) that require intactsagebrush communities for certain life stages Sage-grousepopulations were predicted to decline to ~43 of theircurrent population size within the next 30 years withinthe Great Basin if the grassndashfire cycle is left unabated(Coates et al 2016) Sage-grouse are a gallinaceous birdspecies with elaborate courtship rituals that exhibit stronglek and site fidelity (Fischer et al 1993 Schroeder andRobb 2003 Connelly et al 2011a) Individuals will oftenreturn to the same breeding area as used in previous yearsand females often nest near previous nest sites (Fischeret al 1993 Schroeder and Robb 2003 ONeil et al 2020)Such behavioral rigidity following disturbance eventscould negatively influence population dynamics (Schroe-der and Robb 2003 Carroll et al 2017) whereby historic-ally beneficial behaviors become maladaptive in an alteredecosystem (Battin 2004 Robertson et al 2013 ONeil et al2020)Prevailing evidence suggests that sage-grouse continue

to occupy burned areas in years immediately followingwildfire instead of seeking out unburned albeit novel al-ternatives (Lockyer et al 2015 Foster et al 2019 Dudley2020 ONeil et al 2020) Wildfire has been known toalter habitat composition (Hess and Beck 2012 Davisand Crawford 2015) and food resources (Rhodes et al2010) and may reduce nest and adult survival (Lockyeret al 2015 Foster et al 2019 Dudley 2020) with poten-tially negative impacts on lek attendance (Steenvoordenet al 2019) This implies that wildfire is likely to haveshort-term negative impacts on sage-grouse populationgrowth and may also reduce long-term habitat popula-tion capacity when permanent state transitions of habitatpatches to annual grass occur (Miller et al 2011)However because multiple stressors may affect popula-tions simultaneously and sage-grouse populations tendto be cyclical (Garton et al 2015 Coates et al 2018Coates et al 2019) it is often difficult to attribute short-term population decline to a single specific causeUnder these circumstances paired study designs thatfacilitate comparisons between affected and unaffectedareas are especially useful for understanding the influ-ence of localized disturbances on populations of conser-vation concern (Conner et al 2016) Within the GreatBasin for example a better understanding of theimpacts of changing wildfire regimes on sage-grousepopulations has become an important resource

management objective (US Fish and Wildlife Service2015 WAFWA 2015 Ricca and Coates 2020)Recent wildfires that burned substantial areas of sage-

brush in northeastern California and northwesternNevada USA have created both opportunity and ur-gency to evaluate short-term impacts on important sage-grouse breeding concentration areas occurring near theperiphery of current sage-grouse distribution In 2012 alarge wildfire (hereafter the Rush Fire) burned approxi-mately 124 000 ha of sagebrush in Lassen CountyCalifornia and Washoe County Nevada (Bureau of LandManagement 2012) an area that supported a breedingpopulation of 1500 to 4500 sage-grouse between 1987and 2003 (Armentrout and Hall 2005) To evaluate theimpact of the Rush Fire on estimated rate of change in

apparent sage-grouse population abundance ( λ ) in thisregion we proposed and implemented a paired study de-

sign contrasting λ within and outside areas that burnedusing sage-grouse lek count data that were recorded be-fore and after a large fire event For wildlife and resourcemanagers the continued use of lek sites by sage-grousefor courtship provides opportunity for annual monitor-ing of sage-grouse populations Lek counts are the mostcommon and cost-effective method for tracking sage-grouse abundance at various spatial scales (Patterson1952 Connelly and Schroeder 2007 Blomberg andHagen 2020) Lek counts were implemented as early asthe 1930s (Johnson and Rowland 2007) so in manycases long-term population trends can be establishedfrom these datasets Lek counts are a direct measure ofmale lek attendance and are generally assumed to trackoverall abundance and population trends (Blomberget al 2013a Monroe et al 2016 Wann et al 2019) Lekcounts have been used to evaluate effects of a variety ofimpacts within the speciesrsquo range stemming from energydevelopment (Green et al 2017) agriculture (Dohertyet al 2016) livestock grazing (Monroe et al 2017) andconifer expansion (Baruch-Mordo et al 2013) as well asprescribed fire (Connelly et al 2000) and wildfire(Coates et al 2016 Steenvoorden et al 2019)The long-term lek count datasets used in our study fa-

cilitated a before-after-control-impact (BACI) analysisdesign using paired datasets (BACIP Stewart-Oatenet al 1986) which are used to make inference about im-pacts of a treatment or disturbance (Queen et al 2002)relative to controls In this case count data collectedfrom leks inside and outside the known fire perimeterprovided a robust BACIP dataset spanning breedingyears prior to and after the Rush Fire (2007 to 2012 and2013 to 2018 respectively) The primary purpose of theBACIP study design is to compare the state of a systemafter the impact of a disturbance to the state of the same

Dudley et al Fire Ecology (2021) 1715 Page 3 of 13

system where the disturbance did not occur while ac-counting for pre-existing spatial heterogeneity and nat-ural temporal change (Green 1979 Stewart-Oaten et al1986 Underwood 1992) Applying a BACI analysis tosage-grouse lek count data provides an empirically basedframework to quantify the effects of this large-scale wild-fire on the population dynamics of a peripheral popula-tion of sage-grouse We hypothesized that populationgrowth rates of leks located inside the Rush Fire perim-eter would be more adversely affected than leks locatedoutside the fire perimeter

MethodsStudy areaOur study took place within the Buffalo-SkedaddlePopulation Management Unit (PMU) in eastern LassenCounty of northeastern California and Washoe Countyin northwestern Nevada (hereinafter Susanville studyarea) The Buffalo-Skedaddle PMU encompasses an areaof approximately 1 172 260 ha The study site which oc-cupied most of the Buffalo-Skedaddle PMU ranged inelevation from 1350 to 2400 m and consisted predomin-antly of public land administered by the Bureau of LandManagement or private lands During the study period(2007 to 2018) the area experienced a mean annual pre-cipitation of 2717 cm (SD = 1411) and a mean annualtemperature of 106 degC (SD = 074 Susanville MunicipalAirport Western Regional Climate Center httpswrccdrieducgi-bincliMAINplca8702) The Rush Fire tookplace in August 2012 (post breeding season) and burnedapproximately 124 000 ha Most of the burn (gt97) oc-curred within the Buffalo-Skedaddle PMU (~18 ofPMU area burned) extending from Skedaddle Mountainto Madeline Plains along the western side of the Califor-niandashNevada state border (Fig 1)Throughout the study area cheatgrass and medusa-

head wildrye were common understory vegetation com-ponents but were more prevalent inside the fireperimeter post-fire (P Coates US Geological SurveyDixon California USA unpublished data) Outside theRush Fire perimeter the plant community was a colddesert shrub steppe dominated big sagebrush (Artemesiatridentata Nutt) dwarf sagebrush (A arbuscula Nutt)and antelope bitterbrush (Purshia tridentata Curran)Silver sagebrush (A cana Pursh) was common in thenorthwest area of the study site The primary land useswere livestock grazing (sheep and cattle) and irrigatedagriculture US Highway 395 and a network of smallerpaved improved gravel and unimproved two-trackroads provided access throughout the study area Thestudy area included 80 sage-grouse leks with 30 consid-ered active (ge2 males observed on at least two separateoccasions during the previous ten years WAFWA 2015)Local breeding abundance estimates for this sub-

population (PMU-level) ranged from 1500 to 4000 indi-viduals between 1987 and 2003 (Armentrout and Hall2005)

Lek countsPersonnel from California Department of Fish and Wild-life (CDFW) Bureau of Land Management (BLM) USForest Service (USFS) and US Geological Survey (USGS)used established protocols (Connelly et al 2003) tocount sage-grouse leks within the Susanville study areafrom early March to late April spanning the period ofpeak lek attendance by males in this region (Wann et al2019) Lek counts were conducted between 30 min be-fore and 90 min after sunrise by ground observers usingbinoculars spotting scopes or both from suitable obser-vation locations Three lek counts were conducted dur-ing a single survey and the highest male count wasrecorded Each lek was counted multiple times duringthe breeding season and the maximum male count wasassumed to represent peak male attendance for each lekfrom 2007 to 2018 All lek count data used for analyseswere obtained from the Western Association of Fish andWildlife Agencies dataset and were subject to QA andQC measures (WAFWA 2015) prior to analysis

To estimate the impact of the Rush Fire on λ we usedcount data from 15 active leks located within the Buffalo-Skedaddle PMU (Fig 1) Leks used in the analysis had tohave an active status within the WAFWA dataset andfewer than five missing counts over the 12-year studyperiod We overlaid leks that met those criteria with wild-fire spatial data collected from the Monitoring Trends inBurn Severity (Eidenshink et al 2007) database andassigned a categorical fire affiliation of inside (n = 6impact) or outside (n = 9 control) based on their locationrelative to the Rush Fire perimeter (Fig 1) Leks locatedoutside the fire perimeter had an average distance of123 km (SD = 84 km) to the nearest fire perimeteredge and ranged from 03 to 270 km outside the fireperimeter Leks located inside the fire perimeter hadan average distance of 47 km (SD = 35 km) to thenearest fire perimeter edge and ranged from 02 to90 km inside the fire perimeter

Modeling approachWe used a statendashspace modeling (hereafter SSM) ap-proach in a Bayesian framework (Royle and Dorazio

2008 Keacutery and Schaub 2011) to estimate λ from lekcount data collected from a population of sage-grousewithin the Susanville study area The advantage of SSMover other methods is that it accounts for observationerror (ε ie detections are imperfect) and it is inher-ently Markovian which was appropriate for these timeseries data We bifurcated the modeling process based

Dudley et al Fire Ecology (2021) 1715 Page 4 of 13

system where the disturbance did not occur while ac-counting for pre-existing spatial heterogeneity and nat-ural temporal change (Green 1979 Stewart-Oaten et al1986 Underwood 1992) Applying a BACI analysis tosage-grouse lek count data provides an empirically basedframework to quantify the effects of this large-scale wild-fire on the population dynamics of a peripheral popula-tion of sage-grouse We hypothesized that populationgrowth rates of leks located inside the Rush Fire perim-eter would be more adversely affected than leks locatedoutside the fire perimeter

MethodsStudy areaOur study took place within the Buffalo-SkedaddlePopulation Management Unit (PMU) in eastern LassenCounty of northeastern California and Washoe Countyin northwestern Nevada (hereinafter Susanville studyarea) The Buffalo-Skedaddle PMU encompasses an areaof approximately 1 172 260 ha The study site which oc-cupied most of the Buffalo-Skedaddle PMU ranged inelevation from 1350 to 2400 m and consisted predomin-antly of public land administered by the Bureau of LandManagement or private lands During the study period(2007 to 2018) the area experienced a mean annual pre-cipitation of 2717 cm (SD = 1411) and a mean annualtemperature of 106 degC (SD = 074 Susanville MunicipalAirport Western Regional Climate Center httpswrccdrieducgi-bincliMAINplca8702) The Rush Fire tookplace in August 2012 (post breeding season) and burnedapproximately 124 000 ha Most of the burn (gt97) oc-curred within the Buffalo-Skedaddle PMU (~18 ofPMU area burned) extending from Skedaddle Mountainto Madeline Plains along the western side of the Califor-niandashNevada state border (Fig 1)Throughout the study area cheatgrass and medusa-

head wildrye were common understory vegetation com-ponents but were more prevalent inside the fireperimeter post-fire (P Coates US Geological SurveyDixon California USA unpublished data) Outside theRush Fire perimeter the plant community was a colddesert shrub steppe dominated big sagebrush (Artemesiatridentata Nutt) dwarf sagebrush (A arbuscula Nutt)and antelope bitterbrush (Purshia tridentata Curran)Silver sagebrush (A cana Pursh) was common in thenorthwest area of the study site The primary land useswere livestock grazing (sheep and cattle) and irrigatedagriculture US Highway 395 and a network of smallerpaved improved gravel and unimproved two-trackroads provided access throughout the study area Thestudy area included 80 sage-grouse leks with 30 consid-ered active (ge2 males observed on at least two separateoccasions during the previous ten years WAFWA 2015)Local breeding abundance estimates for this sub-

population (PMU-level) ranged from 1500 to 4000 indi-viduals between 1987 and 2003 (Armentrout and Hall2005)

Lek countsPersonnel from California Department of Fish and Wild-life (CDFW) Bureau of Land Management (BLM) USForest Service (USFS) and US Geological Survey (USGS)used established protocols (Connelly et al 2003) tocount sage-grouse leks within the Susanville study areafrom early March to late April spanning the period ofpeak lek attendance by males in this region (Wann et al2019) Lek counts were conducted between 30 min be-fore and 90 min after sunrise by ground observers usingbinoculars spotting scopes or both from suitable obser-vation locations Three lek counts were conducted dur-ing a single survey and the highest male count wasrecorded Each lek was counted multiple times duringthe breeding season and the maximum male count wasassumed to represent peak male attendance for each lekfrom 2007 to 2018 All lek count data used for analyseswere obtained from the Western Association of Fish andWildlife Agencies dataset and were subject to QA andQC measures (WAFWA 2015) prior to analysis

To estimate the impact of the Rush Fire on λ we usedcount data from 15 active leks located within the Buffalo-Skedaddle PMU (Fig 1) Leks used in the analysis had tohave an active status within the WAFWA dataset andfewer than five missing counts over the 12-year studyperiod We overlaid leks that met those criteria with wild-fire spatial data collected from the Monitoring Trends inBurn Severity (Eidenshink et al 2007) database andassigned a categorical fire affiliation of inside (n = 6impact) or outside (n = 9 control) based on their locationrelative to the Rush Fire perimeter (Fig 1) Leks locatedoutside the fire perimeter had an average distance of123 km (SD = 84 km) to the nearest fire perimeteredge and ranged from 03 to 270 km outside the fireperimeter Leks located inside the fire perimeter hadan average distance of 47 km (SD = 35 km) to thenearest fire perimeter edge and ranged from 02 to90 km inside the fire perimeter

Modeling approachWe used a statendashspace modeling (hereafter SSM) ap-proach in a Bayesian framework (Royle and Dorazio

2008 Keacutery and Schaub 2011) to estimate λ from lekcount data collected from a population of sage-grousewithin the Susanville study area The advantage of SSMover other methods is that it accounts for observationerror (ε ie detections are imperfect) and it is inher-ently Markovian which was appropriate for these timeseries data We bifurcated the modeling process based

Dudley et al Fire Ecology (2021) 1715 Page 4 of 13

Fig 1 Map of greater sage-grouse (Centrocercus urophasianus) study site (Buffalo-Skedaddle PMU) in northeastern Lassen County California andnorthwestern Washoe County Nevada USA between 2007 to 2018 The solid black line represents the Buffalo-Skedaddle PMU boundary (redpolygon in inset map) The pink shaded polygon indicates the extent of the 2012 Rush Fire Leks assigned to the control group (unburned leksblack dots) were located between 03 to 270 km outside the fire perimeter Leks assigned to the impact group (burned leks red asterisks) werelocated between 02 to 90 km inside the fire perimeter

Dudley et al Fire Ecology (2021) 1715 Page 5 of 13

on fire category (ie inside perimeter outside perimeter)and applied a set of hierarchical equations to the lektime series data referred to as the process (true but la-tent state) and observation (relationship of observationdata to latent state) components of the SSM For bothfire categories the process component of this model wasexpressed as

log N l jthorn1 frac14 log N lj

thorn rlj eth1THORN

rlj Normal rl σ2rl

eth2THORN

and the observation component was expressed as

log ylj

frac14 log N lj thorn εlj eth3THORN

εlj Normal 0 σ2yl

eth4THORN

log N l1 Uniform minus5 5eth THORN eth5THORN

We used log-transformed lek counts within the model-ing process and used intrinsic growth rate ethrTHORN as apopulation rate of change parameter for each lek (l) andeach year (j) with normally distributed mean intrinsicgrowth rate with variance parameter ethσ2rlTHORN (Keacutery andSchaub 2011 Green et al 2017) We assigned a vagueprior to the mean intrinsic growth rate (rlTHORN for each lekA vague prior was also specified for the initial popula-tion size (N l1 ) using a uniform distribution with lower(minus5) and upper (5) limits which approximated a rangeof 0 to 150 on a linear scale The upper limit was ap-proximately twice the maximum observed initial lekcount for the population and thus provided ample spacefor estimating N l1 We derived the finite rate of increase

(λ) from r using the equation

λlj frac14 exp rlj

eth6THORN

We sampled 100 000 model iterations from three in-dependent chains after a burn in of 50 000 iterationsPosterior samples saved for inference were thinned by afactor of five Statistical analyses were conducted usingprogram JAGS version 43 (Plummer 2017) run throughprogram R version 340 (R Core Team 2017) usingpacking rjags (Plummer 2019)

BACIP ratios and controlndashimpact measuresTo evaluate the effect of the Rush Fire on populationgrowth of sage-grouse we applied BACI ratio method-ologies (Conner et al 2016) and two controlndashimpact(CI) measures (Chevalier et al 2019) to the posteriordistributions of estimated growth rates at leks catego-rized by fire impact versus controlWe assigned posterior distributions of population

growth rate estimates ( λ jg) to a year (j) and group (g)where the group-level index was categorized as either in-side (ie impact i) or outside (ie control c) the RushFire perimeter Population growth rate ratios (R

λijc) were

calculated on an annual basis

Rλijcfrac14 λji

λjc eth7THORN

where the rate of change at impact sites ( λji ) served asthe numerator and the rate of change at control sites

(λjc ) served as the denominator We averaged annual rateof change ratios across two time periods corresponding toeither before (2007 to 2008 2011 to 2012 R

λijc before

) or

after (2012 to 2013 2017 to 2018 Rλijc after

) the wildfire

event Because λ in year j was calculated as the change inabundance from year j to j+1 and because the Rush Fireoccurred between population counts in 2012 and 2013

we assigned the λ and R values for 2012 to the afterperiod To estimate the relative wildfire effect on popula-tion rate of change ethR

λBACI

THORN we divided the rate of change

ratio of the after period by the before period

RλBACIfrac14

Rλijc after

Rλijc before

eth8THORN

We calculated two additional CI measures (CI-contri-bution and CI-divergence) to provide greater insight intonot only the magnitude but also the direction (iesource) of variability among the four BACI groups(Chevalier et al 2019) CI-contribution measures relativechange in the impact area to the control area and wasexpressed as

CI minus contribution frac14 λiafter minus λibefore

minus λcafter minus λcbefore

eth9THORNwhere positive values indicate that changes in the impactareas are driving overall system observed changes

Dudley et al Fire Ecology (2021) 1715 Page 6 of 13

Conversely negative values indicate that changes in thecontrol area are driving overall observed changesCI-divergence measures the dissimilarity of impact

and control areas after the wildfire relative to before thewildfire and was expressed as

CI minus divergence frac14 λiafter minus λcafter

minus λibefore minus λcbefore

eth10THORN

Positive CI-divergence values indicate that differencesbetween control and impact population growth rateshave increased (ie are more dissimilar) after the wild-fire as compared to before the wildfire Negative valuesindicate that control and impact population growth ratesafter the wildfire are more similar as compared to beforethe wildfire

ResultsWe used count data from six leks located inside and nineleks located outside the Rush Fire perimeter (Fig 1) Be-

fore the Rush Fire λ at leks that later burned (ie oc-curred inside the Rush Fire perimeter impact group) weregenerally higher (108 95 Credible Interval [CRI Lee1997] = 099 to 114) than leks that did not burn (097

95 CRI = 088 to 103) Conversely after the Rush Fire λat burned leks was generally lower (088 95 CRI = 084to 095) than for unburned leks (095 95 CRI = 091 to104 Fig 2) Using a BACI ratio approach we found that

the mean λ ratio after the Rush Fire (Rλijc after

) had a me-

dian value of 094 (95 CRI = 086 to 103) and was less

than the mean λ ratio before the fire (Rλijc before

) which had

a median value of 113 (95 CRI = 102 to 127 Fig 2) Interms of posterior evidence we found that R

λijc after

had

nearly 73 times as many posterior samples below 1 (~910)as compared to R

λijc before

(~13 of posterior samples) This

suggests little evidence of a lower λ value across leks insidethe fire compared to leks outside the fire prior to the fire

event Conversely there was strong evidence for lower λvalues across leks inside the fire compared to leks outsidethe fire following the fire eventThe overall median effect (R

λBACI

) was 084 indicating that

λ at burned leks decreased approximately 16 (95 CRI =

071 to 098) relative to λ at unburned leks following theRush Fire Moreover approximately 985 of the posteriordistribution of the ratio estimate was lt1 indicating substan-tial evidence of negative rate of change (Fig 3) CI measures

indicate that the observed change in λ after the Rush Fire

was largely due to a change in λ at the burned leks (CI-con-tribution = 014 95 CRI = minus001 to 026) with moderate

evidence of λ between burned and unburned leks be-coming more similar after the Rush Fire (median CI-divergence = minus004 95 CRI = minus015 to 007)

DiscussionAssessing the impacts of disturbance on wildlife popula-tions is a cornerstone of wildlife conservation We evalu-ated the localized impacts of wildfire a dynamicdisturbance type that is central to management and con-servation of sage-grouse in the Great Basin (Miller et al2011 US Fish and Wildlife Service 2015 Coates et al2016) Using a robust time series of lek counts that tookplace before and after a major wildfire event we wereable to isolate the influence that a specific wildfire eventhad on the local sage-grouse population by making useof a BACIP experimental design within a Bayesian hier-archical SSM framework Sage-grouse populations ex-press cyclical patterns (ranging in duration from 10 to12 years Row and Fedy 2017) and are strongly corre-lated with annual changes in precipitation (Coates et al2018) Yet these potential confounding influences canbe accounted for by measuring the responses of sage-grouse within the same sub-populations before and afterwildfire while contrasting responses inside and outsideburned areas Applying this concept within the BACIframework (Conner et al 2016) we observed strong evi-

dence (985 probability) of negative change in λ atsage-grouse leks affected by a large wildfire relative toleks that occurred outside the fire perimeter (ie not af-

fected) After the fire λ for leks located within the fireperimeter declined by approximately 16 relative tocontrol leks which was based on minimal changes ob-served at those leks located outside the fire perimeter

(median λ before fire = 097 median λ after fire = 095)Our results indicate a meaningful shift in local sage-grouse

population dynamics following wildfire The mean λ ratio ofimpact to control before the fire was gt1 (Fig 2C) meaning

that λ inside the fire perimeter was higher than λ outside

the fire perimeter (pre fire) After the fire the mean λ ratio

was lt1 (Fig 2D) meaning that λ inside the fire perimeter

was lower than λ outside the fire perimeter (post fire)Based on the CI-contribution measure the observed

change in λ ratio in the wake of the Rush Fire was largely

due to a change in λ at burned leks and the degree of dis-

similarity in λ among burned and unburned leks de-

creased (ieλ at burned and unburned leks became moresimilar) over the same time period One explanation forthis shift is that habitat conditions prior to wildfire werebetter within the burn perimeter than the more peripheral

Dudley et al Fire Ecology (2021) 1715 Page 7 of 13

habitat outside the burn resulting in superior sage-grousepopulation performance Following the fire howeverhabitat conditions were apparently degraded such thatsage-grouse population responses were no longer superiorwithin the burned area with negative instead of positivetrends in growth rate This change in the BACI ratiocoupled with a now declining population at leks that

burned suggests that localized extirpation within theBuffalo-Skedaddle PMU is a threat to this relatively iso-lated population Sage-grouse populations on the periph-ery of the species distribution such as the population inthe Buffalo-Skedaddle PMU may be at least partiallydependent on dispersal from more interior populationssuggesting implications for the maintenance of lek

Fig 2 Estimated annual population growth rate (λ) of greater sage-grouse (Centrocercus urophasianus) leks (A) before (2007 to 2008 2011 to

2012) and (B) after (2012 to 2013 2017 to 2018) wildfire and ratios of the estimated annual population growth rates (λ) (C) before fire and (D)after fire in burned areas to unburned areas for each year (blue line) and the mean of the ratios (dashed yellow line) for the Rush Fire in LassenCounty California and Washoe County Nevada USA Shaded polygons represent the 95 credible interval limits The vertical line represents theseparation of growth rates in terms of period (before versus after) assignment The horizontal dashed line represents value of 1 for both ratios

Dudley et al Fire Ecology (2021) 1715 Page 8 of 13

connectivity (Knick and Hanser 2011 Knick et al 2013Row et al 2018) The Rush Fire may have isolated thislocal population from more interior and southern popula-tions by fragmenting habitat thereby leading to reducedconnectivity and subsequent short-term population de-cline If declines are not curbed by habitat restoration orrapid recovery efforts (Ricca and Coates 2020) acute long-term impacts become increasingly likely especially consid-ering natural recovery rates of a decade or more for mostsagebrush communities (Pilliod et al 2017 Pyke et al2020)We found that overall population growth was reduced

following wildfire Wildfire can have a variety of impactson the demographics of local sage-grouse populationswhich has been demonstrated in several study regionsand suggests mechanisms for the population declinesthat we observed at the Buffalo-Skedaddle PMU TheRush Fire occurred in August 2012 which implied thatmost if not all hatch-yearsage-grouse chicks were mo-bile and flighted decreasing the likelihood of direct mor-tality caused by fire However the Rush Fire burnedapproximately 80 to 90 of the vegetation within thewildfire perimeter (Bureau of Land Management 2012)Fall and winter resources were likely substantially af-fected because wildfire kills sagebrush which otherwise

provides critical forage and cover for sage-grouse duringthe winter season (Connelly et al 2011b Miller et al2013) For example substantial reductions in wintersurvival were documented following a large wildfire inOregon USA (Foster 2016) Moreover nesting vegeta-tion was severely affected which likely contributed tolow nest survival documented after the fire between2015 and 2018 (Dudley 2020) After the wildfire sage-grouse used a higher percent of non-shrub nest cover in-side the fire perimeter (eg perennial grasses and forbs)than outside the perimeter (Dudley 2020) Increasedhabitat edge by way of fragmentation of sagebrush com-munities may also increase the occupancy and density ofvisual nest predators such as common ravens (Corvuscorax Linnaeus 1758 Howe et al 2014 OrsquoNeil et al2018 Coates et al 2020) with greater potential impactswhere shrub cover has been reduced (Coates and Dele-hanty 2010) Sage-grouse chicks require habitat that pro-vides both cover and foraging opportunity which can becharacterized by a shrub overstory and herbaceousunderstory with an abundance of insects (Connelly et al2011b Blomberg et al 2013b Gibson et al 2017) Nativeplant communities including shrub overstory may bereplaced by annual grasses after wildfire (Chamberset al 2007 Beck et al 2009 Miller et al 2013 Chamberset al 2014) Such habitat conversion can also negativelyaffect insect abundance (Beck et al 2012) Rhodes et al(2010) found that fire reduced the abundance of ants(Hymenoptera) an important food source for youngsage-grouse chicks While the Rush Fire occurred aftercritical nesting and brood rearing seasons in 2012 thelocal sage-grouse populations were likely subject tolong-term seasonal indirect effects through impacts oncover and food resources and could have lasting effectson the sagebrush community in areas of low ecosystemresistance and resilience (Miller et al 2011 Chamberset al 2014 Coates et al 2016) Continued assessmentsof the sage-grouse demographic responses in this regionare needed to inform post-fire mechanisms contributingto population declineThe extent of large-scale wildfires can exceed the

range of movements exhibited by typical sage-grousepopulations which may constrain adaptive behaviorssuch as nest foraging and lead to maladaptive selectionpatterns (Remeš 2000 ONeil et al 2020) Before theRush Fire female sage-grouse nested on average 37 km(SD = 29) from the nearest lek (Davis et al 2014) whichis significantly less than the average distance betweenthe fire perimeter edge and affected leks used in thisanalysis (mean = 47 km range = 02 to 90 km) Hensthat continue to attend fire-affected leks are less likely toaccess resources and nest beyond the fire perimeter dueto strong patterns of site fidelity (Connelly et al 2011a)and may instead settle in sub-optimal habitats that

Fig 3 Distribution of relative change in population growth rate (λ)of greater sage-grouse (Centrocercus urophasianus) leks in LassenCounty California and Washoe County Nevada USA from beforethe Rush Fire (2007 to 2008 2011 to 2012) to after the Rush Fire(2012 to 2013 2017 to 2018) Relative change below 1 (black

vertical line) indicates a decrease of λ for leks in impact areas(burned) relative to control (unburned) areas after the Rush Fire

whereas relative change above 1 indicates an increase of λ for leksin impact areas relative to control area The percentage of theposterior distribution falling below 1 is indicated by yellow shadingin the legend while the percentage occurring above 1 is indicatedby green shading

Dudley et al Fire Ecology (2021) 1715 Page 9 of 13

contribute to poor performance (Battin 2004) Islands ofunburned habitat could provide partial refuge for sage-grouse occupying areas affected by wildfire (Steenvoordenet al 2019) which could prove to be important in areaswhere sage-grouse exhibit high degrees of site fidelityHowever it is unlikely that habitat in the form of islandscould fully compensate for potential population declinesfollowing fire Although further investigation is needed in-tact sagebrush islands appeared to be sparse within ourstudy area based on estimated loss of native plant commu-nities loss (Bureau of Land Management 2012) and typeconversion to cheatgrass approximately eight yearsfollowing the wildfire (Dudley 2020)Our findings are consistent with several studies show-

ing population impacts on sage-grouse following a majorwildfire event A simulation analysis conducted byPedersen et al (2003) found that under most scenariosfire resulted in reduced sage-grouse populations some-times leading to local population extirpation Resultsfrom Smith and Beck (2018) also demonstrated thatwildfire was associated with immediate and enduring ad-verse impacts on sage-grouse population change suchthat growth rates were reduced for up to 11 years postwildfire In the Great Basin sage-grouse populationswere predicted to decline 57 by 2044 if current annualgrassndashwildfire cycle trends continued (Coates et al2016) The results from our analysis are consistent withthose findings and provide a pattern-based case studythat demonstrates reductions in population size and sug-gests a potential mechanism for species range contrac-tion that can occur when peripheral populations areaffected (eg Coates et al 2019) Although not investi-gated as part of this study reductions in population sizefollowing wildfire are likely a function of reduced ratesof survival and recruitment (Foster et al 2019 Anthony2020 Dudley 2020) as well as potential emigration awayfrom affected areas Additional demographic studies areneeded to identify mechanisms by which wildfire influ-ences population dynamics and the long-term preva-lence of such negative effects

ConclusionsThis study contributes additional evidence that wildfirehas short-term negative impacts on sage-grouse popula-tions Long-term impacts are also likely given the timerequired for sagebrush communities to recover coupledwith the existing threat of permanent state transitions toannual grassland associated with a grassndashfire feedbackcycle (Balch et al 2013 Coates et al 2016 Shriver et al2019) Continued monitoring of wildfire-affected popula-tions is warranted as lingering wildfire effects may re-duce habitat quality and population capacity over anextended period (Coates et al 2016) In addition im-pacts to other sagebrush ecosystem species need

investigation to understand community-wide impacts onspecies diversity Active restoration efforts that facilitatesagebrush regrowth while providing short-term coverand resources for nesting and winter foraging (Pykeet al 2020 Ricca and Coates 2020) may be required tosustain local populations following increasingly frequentwildfire events affecting sage-grouse habitat across theextent of its range

AcknowledgementsWe thank R Croston K Miller and T Kimball for providing helpful commentsthat improved this manuscript This research was supported by funding fromthe California Department of Fish and Wildlife (CDFW) Bureau of LandManagement (BLM) and US Geological Survey (USGS) Collection of fielddata was supported by multiple federal and state agencies including CDFWBLM USGS Idaho State University and University of Idaho We areparticularly grateful to M Ricca (USGS) J Atkinson (USGS) R Kelble (USGS) JSeverson (USGS) S Mathews (USGS) A Johnson (BLM) K Miller (CDFW) andK Collum (BLM) for their contributions to field study logistics data andconceptual design We thank numerous technicians who helped conduct lekcounts Any use of trade firm or product names is for descriptive purposesonly and does not imply endorsement by the US Government

Authorsrsquo contributionsIn alphabetical order of last name PSC and DJD conceived idea anddesign IFD and SCG collected the data BGP IFD and STO analyzedthe data PSC DJD IFD SCG STO and BGP wrote and edited themanuscript PSC DJD and SCG contributed resources and funding Allauthors read and approved the final manuscript

FundingThis research was conducted under grants from California Department ofFish and Wildlife Bureau of Land Management and US Geological Survey

Availability of data and materialsThe data that support the findings of this study are available from CaliforniaDepartment of Fish and Wildlife but restrictions apply to the availability ofthese data which were used under license for the current study and so arenot publicly available Data are however available from the authors uponreasonable request and with permission of California Department of Fish andWildlife

Declarations

Ethics approval and consent to participateNot applicable

Consent for publicationNot applicable

Competing interestsThe authors declare that they have no competing interests

Author details1US Geological Survey Western Ecological Research Center Dixon FieldStation 800 Business Park Drive Suite D Dixon California 95620 USA2Department of Biological Sciences Idaho State University 921 South 8thAvenue Pocatello Idaho 83209 USA 3California Department of Fish andWildlife 1010 Riverside Parkway West Sacramento California 95605 USA

Received 28 July 2020 Accepted 9 March 2021

ReferencesAnthony CR 2020 Thermal ecology and population dynamics of female greater

sage-grouse following wildfire in the Trout Creek Mountains of Oregon andNevada Dissertation Corvallis USA Oregon State University

Armentrout DJ and F Hall 2005 Conservation strategy for sage-grouse(Centrocercus urophasianus) and sagebrush ecosystems within the Buffalo-

Dudley et al Fire Ecology (2021) 1715 Page 10 of 13

Skedaddle Population Management Unit Susanville Bureau of LandManagement Eagle Lake Field Office

Baker WL 2006 Fire and restoration of sagebrush ecosystems Wildlife SocietyBulletin 34 (1) 177ndash185 httpsdoiorg1021930091-7648(2006)34[177FAROSE]20CO2

Balch JK BA Bradley CM DrsquoAntonio and J Goacutemez-Dans 2013 Introducedannual grass increases regional fire activity across the arid western USA(1980-2009) Global Change Biology 19 (1) 173ndash183 httpsdoiorg101111gcb12046

Baruch-Mordo S JS Evans JP Severson DE Naugle JD Maestas JM Kiesecker MJ Falkowski CA Hagen and KP Reese 2013 Saving sage-grouse from the treesa proactive solution to reducing a key threat to a candidate species BiologicalConservation 167 233ndash241 httpsdoiorg101016jbiocon201308017

Battin J 2004 When good animals love bad habitats ecological traps and theconservation of animal populations Conservation Biology 18 (6) 1482ndash1491httpsdoiorg101111j1523-1739200400417x

Beck JL JW Connelly and KP Reese 2009 Recovery of greater sage-grousehabitat features in Wyoming big sagebrush following prescribed fire RestorationEcology 17 (3) 393ndash403 httpsdoiorg101111j1526-100X200800380x

Beck JL JW Connelly and CL Wambolt 2012 Consequences of treatingWyoming big sagebrush to enhance wildlife habitats Rangeland Ecology ampManagement 65 (5) 444ndash455 httpsdoiorg102111REM-D-10-001231

Blomberg E and C Hagen 2020 How many leks does it take Minimumsamples sizes for measuring local-scale conservation outcomes in greatersage-grouse Avian Conservation and Ecology 15 9 httpsdoiorg105751ACE-01517-150109

Blomberg EJ SR Poulson JS Sedinger and D Gibson 2013b Prefledging diet iscorrelated with individual growth in greater sage-grouse (Centrocercusurophasianus) The Auk 130 (4) 715ndash724 httpsdoiorg101525auk201312188

Blomberg EJ JS Sedinger DV Nonne and MT Atamian 2013a Annual malelek attendance influences count-based population indices of greater sage-grouse The Journal of Wildlife Management 77 (8) 1583ndash1592 httpsdoiorg101002jwmg615

Brooks ML CM DrsquoAntonio DM Richardson JB Grace JE Keeley JMDiTomaso RJ Hobbs M Pellant and D Pyke 2004 Effects of invasive alienplants on fire regimes BioScience 54 (7) 677ndash688 httpsdoiorg1016410006-3568(2004)054[0677EOIAPO]20CO2

Brooks ML JR Matchett DJ Shinneman and PS Coates 2015 Fire patterns inthe range of greater sage-grouse 1984-2013 implications for conservationand management In US Geological Survey Open-File Report 2015-1167 RestonUS Geological Survey httpsdoiorg103133ofr20151167

Bunting SC BM Kilgore and CL Bushey 1987 Guidelines for prescribedburning sagebrush-grass rangelands in the northern Great Basin In USDAGeneral Technical Report INT-GTR-231 Ogden USDA Forest ServiceIntermountain Research Station httpsdoiorg102737INT-GTR-231

Bureau of Land Management 2012 Environmental assessment Rush Fireemergency stabilization and rehabilitation DOI-BLM-CA-N050-2012-45-EASusanville Bureau of Land Management Eagle Lake Field Office

Carroll JM TJ Hovick CA Davis RD Elmore and SD Fuhlendorf 2017Reproductive plasticity and landscape heterogeneity benefit a ground-nesting bird in a fire-prone ecosystem Ecological Applications 27 (7) 2234ndash2244 httpsdoiorg101002eap1604

Chambers JC BA Bradley CS Brown C DrsquoAntonio MJ Germino JB Grace SPHardegree RF Miller and DA Pyke 2014 Resilience to stress anddisturbance and resistance to Bromus tectorum L invasion in cold desertshrublands of western North America Ecosystems 17 (2) 360ndash375 httpsdoiorg101007s10021-013-9725-5

Chambers JC BA Roundy RR Blank SE Meyer and A Whittaker 2007 Whatmakes Great Basin sagebrush ecosystems invasible by Bromus tectorumEcological Monographs 77 (1) 117ndash145 httpsdoiorg10189005-1991

Chevalier M JC Russell and J Knape 2019 New measures for evaluation ofenvironmental perturbations using Before-After-Control-Impact analysesEcological Applications 29 (2) e01838 httpsdoiorg101002eap1838

Coates PS and DJ Delehanty 2010 Nest predation of greater sage-grouse inrelation to microhabitat factors and predators Journal of WildlifeManagement 74 (2) 240ndash248 httpsdoiorg1021932009-047

Coates PS ST OrsquoNeil BE Brussee MA Ricca PJ Jackson JB Dinkins KBHowe AM Moser LJ Foster and DJ Delehanty 2020 Broad-scale impactsof an invasive native predator on a sensitive native prey species within theshifting avian community of the North American Great Basin BiologicalConservation 243 article108409 httpsdoiorg101016jbiocon2020108409

Coates PS BG Prochazka MA Ricca BJ Halstead ML Casazza EJ Blomberg BEBrussee L Wiechman J Tebbenkamp SC Gardner and KP Reese 2018 Therelative importance of intrinsic and extrinsic drivers to population growth varyamong local populations of greater sage-grouse an integrated populationmodeling approach Auk 135 (2) 240ndash261 httpsdoiorg101642AUK-17-1371

Coates PS MA Ricca BG Prochazka ML Brooks KE Doherty T Kroger EJBlomberg CA Hagen and ML Casazza 2016 Wildfire climate and invasivegrass interactions negatively impact an indicator species by reshapingsagebrush ecosystems Proceedings of the National Academy of Sciences 113(45) 12745ndash12750 httpsdoiorg101073pnas1606898113

Coates PS MA Ricca BG Prochazka ST OrsquoNeil JP Severson SR Mathews SEspinosa S Gardner S Lisius and DJ Delehanty 2019 Population andhabitat analyses for greater sage-grouse (Centrocercus urophasianus) in thebi-state distinct population segment 2018 update In US Geological SurveyOpen-File Report 2019-1149 Reston U S Geological Survey httpsdoiorg103133ofr20191149

Connelly JW CA Hagen and MA Schroeder 2011a Characteristics anddynamics of greater sage-grouse populations In Greater sage-grouse ecologyand conservation of a landscape species and its habitats ed ST Knick and JW Connelly 53ndash67 Berkeley University of California Press httpsdoiorg101525california97805202671140030004

Connelly JW ST Knick CE Braun WL Baker EA Beever TJ Christiansen KEDoherty EO Garton CA Hagen SE Hanser DH Johnson M Leu RF MillerDE Naugle SJ Oyler-McCance DA Pyke KP Reese MA Schroeder SJStiver BL Walker and MJ Wisdom 2011b Conservation of greater sage-grousemdasha synthesis of current trends and future management In Greatersage-grouse ecology and conservation of a landscape species and its habitatsed ST Knick and JW Connelly 549ndash563 Berkeley University of CaliforniaPress httpsdoiorg101525california97805202671140030025

Connelly JW KP Reese and MA Schroeder 2003 Monitoring of greater sage-grouse habitats and populations Station bulletin 80 Moscow Idaho Universityof Idaho College of Natural Resources Experiment Station httpsdoiorg105962bhltitle153828

Connelly JW and MA Schroeder 2007 Historical and current approaches tomonitoring greater sage-grouse In Proceedings of a symposium monitoringpopulations of sage-grouse Station bulletin 88 ed KP Reese and RT Bowyer3ndash9 Moscow Idaho University of Idaho College of Natural ResourcesExperiment Station

Connelly JW MA Schroeder AR Sands and CE Braun 2000 Guidelines tomanage sage grouse populations and their habitats Wildlife Society Bulletin28 967ndash985

Conner MM WC Saunders N Bouwes and C Jordan 2016 Evaluating impactsusing a BACI design ratios and a Bayesian approach with a focus onrestoration Environmental Monitoring and Assessment 188 (10) 555 httpsdoiorg101007s10661-016-5526-6

DrsquoAntonio CM and PM Vitousek 1992 Biological invasions by exotic grasses thegrassfire cycle and global change Annual Review of Ecology and Systematics 23(1) 63ndash87 httpsdoiorg101146annureves23110192000431

Davis DM and JA Crawford 2015 Case study short-term response of greatersage-grouse habitats to wildfire in mountain big sagebrush communitiesWildlife Society Bulletin 39 (1) 129ndash137 httpsdoiorg101002wsb505

Davis DM KP Reese and SC Gardner 2014 Diurnal space use and seasonalmovement patterns of greater sage-grouse in northeastern California WildlifeSociety Bulletin 38 (4) 710ndash720 httpsdoiorg101002wsb467

Doherty KE JS Evans PS Coates LM Juliusson and BC Fedy 2016Importance of regional variation in conservation planning a rangewideexample of the greater sage-grouse Ecosphere 7 (10) 1ndash27 httpsdoiorg101002ecs21462

Dudley IF 2020 Maladaptive nest site selection and reduced nest survival in femalesage-grouse following wildfire Thesis Pocatello USA Idaho State University

Eidenshink J B Schwind K Brewer ZL Zhu B Quayle and S Howard 2007 Aproject for monitoring trends in burn severity Fire Ecology 3 (1) 3ndash22 httpsdoiorg104996fireecology0301003

Fischer RA AD Apa WL Wakkinen KP Reese and JW Connelly 1993Nesting-area fidelity of sage grouse in southeastern Idaho Condor 95 (4)1038ndash1041 httpsdoiorg1023071369442

Foster LJ 2016 Resource selection and demographic rats of female sage-grousefollowing large-scale wildfire Thesis Corvallis USA Oregon State University

Foster LJ KM Dugger CA Hagen and DA Budeau 2019 Greater sage-grousevital rates after wildfire Journal of Wildlife Management 83 (1) 121ndash134httpsdoiorg101002jwmg21573

Dudley et al Fire Ecology (2021) 1715 Page 11 of 13

on fire category (ie inside perimeter outside perimeter)and applied a set of hierarchical equations to the lektime series data referred to as the process (true but la-tent state) and observation (relationship of observationdata to latent state) components of the SSM For bothfire categories the process component of this model wasexpressed as

log N l jthorn1 frac14 log N lj

thorn rlj eth1THORN

rlj Normal rl σ2rl

eth2THORN

and the observation component was expressed as

log ylj

frac14 log N lj thorn εlj eth3THORN

εlj Normal 0 σ2yl

eth4THORN

log N l1 Uniform minus5 5eth THORN eth5THORN

We used log-transformed lek counts within the model-ing process and used intrinsic growth rate ethrTHORN as apopulation rate of change parameter for each lek (l) andeach year (j) with normally distributed mean intrinsicgrowth rate with variance parameter ethσ2rlTHORN (Keacutery andSchaub 2011 Green et al 2017) We assigned a vagueprior to the mean intrinsic growth rate (rlTHORN for each lekA vague prior was also specified for the initial popula-tion size (N l1 ) using a uniform distribution with lower(minus5) and upper (5) limits which approximated a rangeof 0 to 150 on a linear scale The upper limit was ap-proximately twice the maximum observed initial lekcount for the population and thus provided ample spacefor estimating N l1 We derived the finite rate of increase

(λ) from r using the equation

λlj frac14 exp rlj

eth6THORN

We sampled 100 000 model iterations from three in-dependent chains after a burn in of 50 000 iterationsPosterior samples saved for inference were thinned by afactor of five Statistical analyses were conducted usingprogram JAGS version 43 (Plummer 2017) run throughprogram R version 340 (R Core Team 2017) usingpacking rjags (Plummer 2019)

BACIP ratios and controlndashimpact measuresTo evaluate the effect of the Rush Fire on populationgrowth of sage-grouse we applied BACI ratio method-ologies (Conner et al 2016) and two controlndashimpact(CI) measures (Chevalier et al 2019) to the posteriordistributions of estimated growth rates at leks catego-rized by fire impact versus controlWe assigned posterior distributions of population

growth rate estimates ( λ jg) to a year (j) and group (g)where the group-level index was categorized as either in-side (ie impact i) or outside (ie control c) the RushFire perimeter Population growth rate ratios (R

λijc) were

calculated on an annual basis

Rλijcfrac14 λji

λjc eth7THORN

where the rate of change at impact sites ( λji ) served asthe numerator and the rate of change at control sites

(λjc ) served as the denominator We averaged annual rateof change ratios across two time periods corresponding toeither before (2007 to 2008 2011 to 2012 R

λijc before

) or

after (2012 to 2013 2017 to 2018 Rλijc after

) the wildfire

event Because λ in year j was calculated as the change inabundance from year j to j+1 and because the Rush Fireoccurred between population counts in 2012 and 2013

we assigned the λ and R values for 2012 to the afterperiod To estimate the relative wildfire effect on popula-tion rate of change ethR

λBACI

THORN we divided the rate of change

ratio of the after period by the before period

RλBACIfrac14

Rλijc after

Rλijc before

eth8THORN

We calculated two additional CI measures (CI-contri-bution and CI-divergence) to provide greater insight intonot only the magnitude but also the direction (iesource) of variability among the four BACI groups(Chevalier et al 2019) CI-contribution measures relativechange in the impact area to the control area and wasexpressed as

CI minus contribution frac14 λiafter minus λibefore

minus λcafter minus λcbefore

eth9THORNwhere positive values indicate that changes in the impactareas are driving overall system observed changes

Dudley et al Fire Ecology (2021) 1715 Page 6 of 13

Conversely negative values indicate that changes in thecontrol area are driving overall observed changesCI-divergence measures the dissimilarity of impact

and control areas after the wildfire relative to before thewildfire and was expressed as

CI minus divergence frac14 λiafter minus λcafter

minus λibefore minus λcbefore

eth10THORN

Positive CI-divergence values indicate that differencesbetween control and impact population growth rateshave increased (ie are more dissimilar) after the wild-fire as compared to before the wildfire Negative valuesindicate that control and impact population growth ratesafter the wildfire are more similar as compared to beforethe wildfire

ResultsWe used count data from six leks located inside and nineleks located outside the Rush Fire perimeter (Fig 1) Be-

fore the Rush Fire λ at leks that later burned (ie oc-curred inside the Rush Fire perimeter impact group) weregenerally higher (108 95 Credible Interval [CRI Lee1997] = 099 to 114) than leks that did not burn (097

95 CRI = 088 to 103) Conversely after the Rush Fire λat burned leks was generally lower (088 95 CRI = 084to 095) than for unburned leks (095 95 CRI = 091 to104 Fig 2) Using a BACI ratio approach we found that

the mean λ ratio after the Rush Fire (Rλijc after

) had a me-

dian value of 094 (95 CRI = 086 to 103) and was less

than the mean λ ratio before the fire (Rλijc before

) which had

a median value of 113 (95 CRI = 102 to 127 Fig 2) Interms of posterior evidence we found that R

λijc after

had

nearly 73 times as many posterior samples below 1 (~910)as compared to R

λijc before

(~13 of posterior samples) This

suggests little evidence of a lower λ value across leks insidethe fire compared to leks outside the fire prior to the fire

event Conversely there was strong evidence for lower λvalues across leks inside the fire compared to leks outsidethe fire following the fire eventThe overall median effect (R

λBACI

) was 084 indicating that

λ at burned leks decreased approximately 16 (95 CRI =

071 to 098) relative to λ at unburned leks following theRush Fire Moreover approximately 985 of the posteriordistribution of the ratio estimate was lt1 indicating substan-tial evidence of negative rate of change (Fig 3) CI measures

indicate that the observed change in λ after the Rush Fire

was largely due to a change in λ at the burned leks (CI-con-tribution = 014 95 CRI = minus001 to 026) with moderate

evidence of λ between burned and unburned leks be-coming more similar after the Rush Fire (median CI-divergence = minus004 95 CRI = minus015 to 007)

DiscussionAssessing the impacts of disturbance on wildlife popula-tions is a cornerstone of wildlife conservation We evalu-ated the localized impacts of wildfire a dynamicdisturbance type that is central to management and con-servation of sage-grouse in the Great Basin (Miller et al2011 US Fish and Wildlife Service 2015 Coates et al2016) Using a robust time series of lek counts that tookplace before and after a major wildfire event we wereable to isolate the influence that a specific wildfire eventhad on the local sage-grouse population by making useof a BACIP experimental design within a Bayesian hier-archical SSM framework Sage-grouse populations ex-press cyclical patterns (ranging in duration from 10 to12 years Row and Fedy 2017) and are strongly corre-lated with annual changes in precipitation (Coates et al2018) Yet these potential confounding influences canbe accounted for by measuring the responses of sage-grouse within the same sub-populations before and afterwildfire while contrasting responses inside and outsideburned areas Applying this concept within the BACIframework (Conner et al 2016) we observed strong evi-

dence (985 probability) of negative change in λ atsage-grouse leks affected by a large wildfire relative toleks that occurred outside the fire perimeter (ie not af-

fected) After the fire λ for leks located within the fireperimeter declined by approximately 16 relative tocontrol leks which was based on minimal changes ob-served at those leks located outside the fire perimeter

(median λ before fire = 097 median λ after fire = 095)Our results indicate a meaningful shift in local sage-grouse

population dynamics following wildfire The mean λ ratio ofimpact to control before the fire was gt1 (Fig 2C) meaning

that λ inside the fire perimeter was higher than λ outside

the fire perimeter (pre fire) After the fire the mean λ ratio

was lt1 (Fig 2D) meaning that λ inside the fire perimeter

was lower than λ outside the fire perimeter (post fire)Based on the CI-contribution measure the observed

change in λ ratio in the wake of the Rush Fire was largely

due to a change in λ at burned leks and the degree of dis-

similarity in λ among burned and unburned leks de-

creased (ieλ at burned and unburned leks became moresimilar) over the same time period One explanation forthis shift is that habitat conditions prior to wildfire werebetter within the burn perimeter than the more peripheral

Dudley et al Fire Ecology (2021) 1715 Page 7 of 13

habitat outside the burn resulting in superior sage-grousepopulation performance Following the fire howeverhabitat conditions were apparently degraded such thatsage-grouse population responses were no longer superiorwithin the burned area with negative instead of positivetrends in growth rate This change in the BACI ratiocoupled with a now declining population at leks that

burned suggests that localized extirpation within theBuffalo-Skedaddle PMU is a threat to this relatively iso-lated population Sage-grouse populations on the periph-ery of the species distribution such as the population inthe Buffalo-Skedaddle PMU may be at least partiallydependent on dispersal from more interior populationssuggesting implications for the maintenance of lek

Fig 2 Estimated annual population growth rate (λ) of greater sage-grouse (Centrocercus urophasianus) leks (A) before (2007 to 2008 2011 to

2012) and (B) after (2012 to 2013 2017 to 2018) wildfire and ratios of the estimated annual population growth rates (λ) (C) before fire and (D)after fire in burned areas to unburned areas for each year (blue line) and the mean of the ratios (dashed yellow line) for the Rush Fire in LassenCounty California and Washoe County Nevada USA Shaded polygons represent the 95 credible interval limits The vertical line represents theseparation of growth rates in terms of period (before versus after) assignment The horizontal dashed line represents value of 1 for both ratios

Dudley et al Fire Ecology (2021) 1715 Page 8 of 13

connectivity (Knick and Hanser 2011 Knick et al 2013Row et al 2018) The Rush Fire may have isolated thislocal population from more interior and southern popula-tions by fragmenting habitat thereby leading to reducedconnectivity and subsequent short-term population de-cline If declines are not curbed by habitat restoration orrapid recovery efforts (Ricca and Coates 2020) acute long-term impacts become increasingly likely especially consid-ering natural recovery rates of a decade or more for mostsagebrush communities (Pilliod et al 2017 Pyke et al2020)We found that overall population growth was reduced

following wildfire Wildfire can have a variety of impactson the demographics of local sage-grouse populationswhich has been demonstrated in several study regionsand suggests mechanisms for the population declinesthat we observed at the Buffalo-Skedaddle PMU TheRush Fire occurred in August 2012 which implied thatmost if not all hatch-yearsage-grouse chicks were mo-bile and flighted decreasing the likelihood of direct mor-tality caused by fire However the Rush Fire burnedapproximately 80 to 90 of the vegetation within thewildfire perimeter (Bureau of Land Management 2012)Fall and winter resources were likely substantially af-fected because wildfire kills sagebrush which otherwise

provides critical forage and cover for sage-grouse duringthe winter season (Connelly et al 2011b Miller et al2013) For example substantial reductions in wintersurvival were documented following a large wildfire inOregon USA (Foster 2016) Moreover nesting vegeta-tion was severely affected which likely contributed tolow nest survival documented after the fire between2015 and 2018 (Dudley 2020) After the wildfire sage-grouse used a higher percent of non-shrub nest cover in-side the fire perimeter (eg perennial grasses and forbs)than outside the perimeter (Dudley 2020) Increasedhabitat edge by way of fragmentation of sagebrush com-munities may also increase the occupancy and density ofvisual nest predators such as common ravens (Corvuscorax Linnaeus 1758 Howe et al 2014 OrsquoNeil et al2018 Coates et al 2020) with greater potential impactswhere shrub cover has been reduced (Coates and Dele-hanty 2010) Sage-grouse chicks require habitat that pro-vides both cover and foraging opportunity which can becharacterized by a shrub overstory and herbaceousunderstory with an abundance of insects (Connelly et al2011b Blomberg et al 2013b Gibson et al 2017) Nativeplant communities including shrub overstory may bereplaced by annual grasses after wildfire (Chamberset al 2007 Beck et al 2009 Miller et al 2013 Chamberset al 2014) Such habitat conversion can also negativelyaffect insect abundance (Beck et al 2012) Rhodes et al(2010) found that fire reduced the abundance of ants(Hymenoptera) an important food source for youngsage-grouse chicks While the Rush Fire occurred aftercritical nesting and brood rearing seasons in 2012 thelocal sage-grouse populations were likely subject tolong-term seasonal indirect effects through impacts oncover and food resources and could have lasting effectson the sagebrush community in areas of low ecosystemresistance and resilience (Miller et al 2011 Chamberset al 2014 Coates et al 2016) Continued assessmentsof the sage-grouse demographic responses in this regionare needed to inform post-fire mechanisms contributingto population declineThe extent of large-scale wildfires can exceed the

range of movements exhibited by typical sage-grousepopulations which may constrain adaptive behaviorssuch as nest foraging and lead to maladaptive selectionpatterns (Remeš 2000 ONeil et al 2020) Before theRush Fire female sage-grouse nested on average 37 km(SD = 29) from the nearest lek (Davis et al 2014) whichis significantly less than the average distance betweenthe fire perimeter edge and affected leks used in thisanalysis (mean = 47 km range = 02 to 90 km) Hensthat continue to attend fire-affected leks are less likely toaccess resources and nest beyond the fire perimeter dueto strong patterns of site fidelity (Connelly et al 2011a)and may instead settle in sub-optimal habitats that

Fig 3 Distribution of relative change in population growth rate (λ)of greater sage-grouse (Centrocercus urophasianus) leks in LassenCounty California and Washoe County Nevada USA from beforethe Rush Fire (2007 to 2008 2011 to 2012) to after the Rush Fire(2012 to 2013 2017 to 2018) Relative change below 1 (black

vertical line) indicates a decrease of λ for leks in impact areas(burned) relative to control (unburned) areas after the Rush Fire

whereas relative change above 1 indicates an increase of λ for leksin impact areas relative to control area The percentage of theposterior distribution falling below 1 is indicated by yellow shadingin the legend while the percentage occurring above 1 is indicatedby green shading

Dudley et al Fire Ecology (2021) 1715 Page 9 of 13

contribute to poor performance (Battin 2004) Islands ofunburned habitat could provide partial refuge for sage-grouse occupying areas affected by wildfire (Steenvoordenet al 2019) which could prove to be important in areaswhere sage-grouse exhibit high degrees of site fidelityHowever it is unlikely that habitat in the form of islandscould fully compensate for potential population declinesfollowing fire Although further investigation is needed in-tact sagebrush islands appeared to be sparse within ourstudy area based on estimated loss of native plant commu-nities loss (Bureau of Land Management 2012) and typeconversion to cheatgrass approximately eight yearsfollowing the wildfire (Dudley 2020)Our findings are consistent with several studies show-

ing population impacts on sage-grouse following a majorwildfire event A simulation analysis conducted byPedersen et al (2003) found that under most scenariosfire resulted in reduced sage-grouse populations some-times leading to local population extirpation Resultsfrom Smith and Beck (2018) also demonstrated thatwildfire was associated with immediate and enduring ad-verse impacts on sage-grouse population change suchthat growth rates were reduced for up to 11 years postwildfire In the Great Basin sage-grouse populationswere predicted to decline 57 by 2044 if current annualgrassndashwildfire cycle trends continued (Coates et al2016) The results from our analysis are consistent withthose findings and provide a pattern-based case studythat demonstrates reductions in population size and sug-gests a potential mechanism for species range contrac-tion that can occur when peripheral populations areaffected (eg Coates et al 2019) Although not investi-gated as part of this study reductions in population sizefollowing wildfire are likely a function of reduced ratesof survival and recruitment (Foster et al 2019 Anthony2020 Dudley 2020) as well as potential emigration awayfrom affected areas Additional demographic studies areneeded to identify mechanisms by which wildfire influ-ences population dynamics and the long-term preva-lence of such negative effects

ConclusionsThis study contributes additional evidence that wildfirehas short-term negative impacts on sage-grouse popula-tions Long-term impacts are also likely given the timerequired for sagebrush communities to recover coupledwith the existing threat of permanent state transitions toannual grassland associated with a grassndashfire feedbackcycle (Balch et al 2013 Coates et al 2016 Shriver et al2019) Continued monitoring of wildfire-affected popula-tions is warranted as lingering wildfire effects may re-duce habitat quality and population capacity over anextended period (Coates et al 2016) In addition im-pacts to other sagebrush ecosystem species need

investigation to understand community-wide impacts onspecies diversity Active restoration efforts that facilitatesagebrush regrowth while providing short-term coverand resources for nesting and winter foraging (Pykeet al 2020 Ricca and Coates 2020) may be required tosustain local populations following increasingly frequentwildfire events affecting sage-grouse habitat across theextent of its range

AcknowledgementsWe thank R Croston K Miller and T Kimball for providing helpful commentsthat improved this manuscript This research was supported by funding fromthe California Department of Fish and Wildlife (CDFW) Bureau of LandManagement (BLM) and US Geological Survey (USGS) Collection of fielddata was supported by multiple federal and state agencies including CDFWBLM USGS Idaho State University and University of Idaho We areparticularly grateful to M Ricca (USGS) J Atkinson (USGS) R Kelble (USGS) JSeverson (USGS) S Mathews (USGS) A Johnson (BLM) K Miller (CDFW) andK Collum (BLM) for their contributions to field study logistics data andconceptual design We thank numerous technicians who helped conduct lekcounts Any use of trade firm or product names is for descriptive purposesonly and does not imply endorsement by the US Government

Authorsrsquo contributionsIn alphabetical order of last name PSC and DJD conceived idea anddesign IFD and SCG collected the data BGP IFD and STO analyzedthe data PSC DJD IFD SCG STO and BGP wrote and edited themanuscript PSC DJD and SCG contributed resources and funding Allauthors read and approved the final manuscript

FundingThis research was conducted under grants from California Department ofFish and Wildlife Bureau of Land Management and US Geological Survey

Availability of data and materialsThe data that support the findings of this study are available from CaliforniaDepartment of Fish and Wildlife but restrictions apply to the availability ofthese data which were used under license for the current study and so arenot publicly available Data are however available from the authors uponreasonable request and with permission of California Department of Fish andWildlife

Declarations

Ethics approval and consent to participateNot applicable

Consent for publicationNot applicable

Competing interestsThe authors declare that they have no competing interests

Author details1US Geological Survey Western Ecological Research Center Dixon FieldStation 800 Business Park Drive Suite D Dixon California 95620 USA2Department of Biological Sciences Idaho State University 921 South 8thAvenue Pocatello Idaho 83209 USA 3California Department of Fish andWildlife 1010 Riverside Parkway West Sacramento California 95605 USA

Received 28 July 2020 Accepted 9 March 2021

ReferencesAnthony CR 2020 Thermal ecology and population dynamics of female greater

sage-grouse following wildfire in the Trout Creek Mountains of Oregon andNevada Dissertation Corvallis USA Oregon State University

Armentrout DJ and F Hall 2005 Conservation strategy for sage-grouse(Centrocercus urophasianus) and sagebrush ecosystems within the Buffalo-

Dudley et al Fire Ecology (2021) 1715 Page 10 of 13

Skedaddle Population Management Unit Susanville Bureau of LandManagement Eagle Lake Field Office

Baker WL 2006 Fire and restoration of sagebrush ecosystems Wildlife SocietyBulletin 34 (1) 177ndash185 httpsdoiorg1021930091-7648(2006)34[177FAROSE]20CO2

Balch JK BA Bradley CM DrsquoAntonio and J Goacutemez-Dans 2013 Introducedannual grass increases regional fire activity across the arid western USA(1980-2009) Global Change Biology 19 (1) 173ndash183 httpsdoiorg101111gcb12046

Baruch-Mordo S JS Evans JP Severson DE Naugle JD Maestas JM Kiesecker MJ Falkowski CA Hagen and KP Reese 2013 Saving sage-grouse from the treesa proactive solution to reducing a key threat to a candidate species BiologicalConservation 167 233ndash241 httpsdoiorg101016jbiocon201308017

Battin J 2004 When good animals love bad habitats ecological traps and theconservation of animal populations Conservation Biology 18 (6) 1482ndash1491httpsdoiorg101111j1523-1739200400417x

Beck JL JW Connelly and KP Reese 2009 Recovery of greater sage-grousehabitat features in Wyoming big sagebrush following prescribed fire RestorationEcology 17 (3) 393ndash403 httpsdoiorg101111j1526-100X200800380x

Beck JL JW Connelly and CL Wambolt 2012 Consequences of treatingWyoming big sagebrush to enhance wildlife habitats Rangeland Ecology ampManagement 65 (5) 444ndash455 httpsdoiorg102111REM-D-10-001231

Blomberg E and C Hagen 2020 How many leks does it take Minimumsamples sizes for measuring local-scale conservation outcomes in greatersage-grouse Avian Conservation and Ecology 15 9 httpsdoiorg105751ACE-01517-150109

Blomberg EJ SR Poulson JS Sedinger and D Gibson 2013b Prefledging diet iscorrelated with individual growth in greater sage-grouse (Centrocercusurophasianus) The Auk 130 (4) 715ndash724 httpsdoiorg101525auk201312188

Blomberg EJ JS Sedinger DV Nonne and MT Atamian 2013a Annual malelek attendance influences count-based population indices of greater sage-grouse The Journal of Wildlife Management 77 (8) 1583ndash1592 httpsdoiorg101002jwmg615

Brooks ML CM DrsquoAntonio DM Richardson JB Grace JE Keeley JMDiTomaso RJ Hobbs M Pellant and D Pyke 2004 Effects of invasive alienplants on fire regimes BioScience 54 (7) 677ndash688 httpsdoiorg1016410006-3568(2004)054[0677EOIAPO]20CO2

Brooks ML JR Matchett DJ Shinneman and PS Coates 2015 Fire patterns inthe range of greater sage-grouse 1984-2013 implications for conservationand management In US Geological Survey Open-File Report 2015-1167 RestonUS Geological Survey httpsdoiorg103133ofr20151167

Bunting SC BM Kilgore and CL Bushey 1987 Guidelines for prescribedburning sagebrush-grass rangelands in the northern Great Basin In USDAGeneral Technical Report INT-GTR-231 Ogden USDA Forest ServiceIntermountain Research Station httpsdoiorg102737INT-GTR-231

Bureau of Land Management 2012 Environmental assessment Rush Fireemergency stabilization and rehabilitation DOI-BLM-CA-N050-2012-45-EASusanville Bureau of Land Management Eagle Lake Field Office

Carroll JM TJ Hovick CA Davis RD Elmore and SD Fuhlendorf 2017Reproductive plasticity and landscape heterogeneity benefit a ground-nesting bird in a fire-prone ecosystem Ecological Applications 27 (7) 2234ndash2244 httpsdoiorg101002eap1604

Chambers JC BA Bradley CS Brown C DrsquoAntonio MJ Germino JB Grace SPHardegree RF Miller and DA Pyke 2014 Resilience to stress anddisturbance and resistance to Bromus tectorum L invasion in cold desertshrublands of western North America Ecosystems 17 (2) 360ndash375 httpsdoiorg101007s10021-013-9725-5

Chambers JC BA Roundy RR Blank SE Meyer and A Whittaker 2007 Whatmakes Great Basin sagebrush ecosystems invasible by Bromus tectorumEcological Monographs 77 (1) 117ndash145 httpsdoiorg10189005-1991

Chevalier M JC Russell and J Knape 2019 New measures for evaluation ofenvironmental perturbations using Before-After-Control-Impact analysesEcological Applications 29 (2) e01838 httpsdoiorg101002eap1838

Coates PS and DJ Delehanty 2010 Nest predation of greater sage-grouse inrelation to microhabitat factors and predators Journal of WildlifeManagement 74 (2) 240ndash248 httpsdoiorg1021932009-047

Coates PS ST OrsquoNeil BE Brussee MA Ricca PJ Jackson JB Dinkins KBHowe AM Moser LJ Foster and DJ Delehanty 2020 Broad-scale impactsof an invasive native predator on a sensitive native prey species within theshifting avian community of the North American Great Basin BiologicalConservation 243 article108409 httpsdoiorg101016jbiocon2020108409

Coates PS BG Prochazka MA Ricca BJ Halstead ML Casazza EJ Blomberg BEBrussee L Wiechman J Tebbenkamp SC Gardner and KP Reese 2018 Therelative importance of intrinsic and extrinsic drivers to population growth varyamong local populations of greater sage-grouse an integrated populationmodeling approach Auk 135 (2) 240ndash261 httpsdoiorg101642AUK-17-1371

Coates PS MA Ricca BG Prochazka ML Brooks KE Doherty T Kroger EJBlomberg CA Hagen and ML Casazza 2016 Wildfire climate and invasivegrass interactions negatively impact an indicator species by reshapingsagebrush ecosystems Proceedings of the National Academy of Sciences 113(45) 12745ndash12750 httpsdoiorg101073pnas1606898113

Coates PS MA Ricca BG Prochazka ST OrsquoNeil JP Severson SR Mathews SEspinosa S Gardner S Lisius and DJ Delehanty 2019 Population andhabitat analyses for greater sage-grouse (Centrocercus urophasianus) in thebi-state distinct population segment 2018 update In US Geological SurveyOpen-File Report 2019-1149 Reston U S Geological Survey httpsdoiorg103133ofr20191149

Connelly JW CA Hagen and MA Schroeder 2011a Characteristics anddynamics of greater sage-grouse populations In Greater sage-grouse ecologyand conservation of a landscape species and its habitats ed ST Knick and JW Connelly 53ndash67 Berkeley University of California Press httpsdoiorg101525california97805202671140030004

Connelly JW ST Knick CE Braun WL Baker EA Beever TJ Christiansen KEDoherty EO Garton CA Hagen SE Hanser DH Johnson M Leu RF MillerDE Naugle SJ Oyler-McCance DA Pyke KP Reese MA Schroeder SJStiver BL Walker and MJ Wisdom 2011b Conservation of greater sage-grousemdasha synthesis of current trends and future management In Greatersage-grouse ecology and conservation of a landscape species and its habitatsed ST Knick and JW Connelly 549ndash563 Berkeley University of CaliforniaPress httpsdoiorg101525california97805202671140030025

Connelly JW KP Reese and MA Schroeder 2003 Monitoring of greater sage-grouse habitats and populations Station bulletin 80 Moscow Idaho Universityof Idaho College of Natural Resources Experiment Station httpsdoiorg105962bhltitle153828

Connelly JW and MA Schroeder 2007 Historical and current approaches tomonitoring greater sage-grouse In Proceedings of a symposium monitoringpopulations of sage-grouse Station bulletin 88 ed KP Reese and RT Bowyer3ndash9 Moscow Idaho University of Idaho College of Natural ResourcesExperiment Station

Connelly JW MA Schroeder AR Sands and CE Braun 2000 Guidelines tomanage sage grouse populations and their habitats Wildlife Society Bulletin28 967ndash985

Conner MM WC Saunders N Bouwes and C Jordan 2016 Evaluating impactsusing a BACI design ratios and a Bayesian approach with a focus onrestoration Environmental Monitoring and Assessment 188 (10) 555 httpsdoiorg101007s10661-016-5526-6

DrsquoAntonio CM and PM Vitousek 1992 Biological invasions by exotic grasses thegrassfire cycle and global change Annual Review of Ecology and Systematics 23(1) 63ndash87 httpsdoiorg101146annureves23110192000431

Davis DM and JA Crawford 2015 Case study short-term response of greatersage-grouse habitats to wildfire in mountain big sagebrush communitiesWildlife Society Bulletin 39 (1) 129ndash137 httpsdoiorg101002wsb505

Davis DM KP Reese and SC Gardner 2014 Diurnal space use and seasonalmovement patterns of greater sage-grouse in northeastern California WildlifeSociety Bulletin 38 (4) 710ndash720 httpsdoiorg101002wsb467

Doherty KE JS Evans PS Coates LM Juliusson and BC Fedy 2016Importance of regional variation in conservation planning a rangewideexample of the greater sage-grouse Ecosphere 7 (10) 1ndash27 httpsdoiorg101002ecs21462

Dudley IF 2020 Maladaptive nest site selection and reduced nest survival in femalesage-grouse following wildfire Thesis Pocatello USA Idaho State University

Eidenshink J B Schwind K Brewer ZL Zhu B Quayle and S Howard 2007 Aproject for monitoring trends in burn severity Fire Ecology 3 (1) 3ndash22 httpsdoiorg104996fireecology0301003

Fischer RA AD Apa WL Wakkinen KP Reese and JW Connelly 1993Nesting-area fidelity of sage grouse in southeastern Idaho Condor 95 (4)1038ndash1041 httpsdoiorg1023071369442

Foster LJ 2016 Resource selection and demographic rats of female sage-grousefollowing large-scale wildfire Thesis Corvallis USA Oregon State University

Foster LJ KM Dugger CA Hagen and DA Budeau 2019 Greater sage-grousevital rates after wildfire Journal of Wildlife Management 83 (1) 121ndash134httpsdoiorg101002jwmg21573

Dudley et al Fire Ecology (2021) 1715 Page 11 of 13

Conversely negative values indicate that changes in thecontrol area are driving overall observed changesCI-divergence measures the dissimilarity of impact

and control areas after the wildfire relative to before thewildfire and was expressed as

CI minus divergence frac14 λiafter minus λcafter

minus λibefore minus λcbefore

eth10THORN

Positive CI-divergence values indicate that differencesbetween control and impact population growth rateshave increased (ie are more dissimilar) after the wild-fire as compared to before the wildfire Negative valuesindicate that control and impact population growth ratesafter the wildfire are more similar as compared to beforethe wildfire

ResultsWe used count data from six leks located inside and nineleks located outside the Rush Fire perimeter (Fig 1) Be-

fore the Rush Fire λ at leks that later burned (ie oc-curred inside the Rush Fire perimeter impact group) weregenerally higher (108 95 Credible Interval [CRI Lee1997] = 099 to 114) than leks that did not burn (097

95 CRI = 088 to 103) Conversely after the Rush Fire λat burned leks was generally lower (088 95 CRI = 084to 095) than for unburned leks (095 95 CRI = 091 to104 Fig 2) Using a BACI ratio approach we found that

the mean λ ratio after the Rush Fire (Rλijc after

) had a me-

dian value of 094 (95 CRI = 086 to 103) and was less

than the mean λ ratio before the fire (Rλijc before

) which had

a median value of 113 (95 CRI = 102 to 127 Fig 2) Interms of posterior evidence we found that R

λijc after

had

nearly 73 times as many posterior samples below 1 (~910)as compared to R

λijc before

(~13 of posterior samples) This

suggests little evidence of a lower λ value across leks insidethe fire compared to leks outside the fire prior to the fire

event Conversely there was strong evidence for lower λvalues across leks inside the fire compared to leks outsidethe fire following the fire eventThe overall median effect (R

λBACI

) was 084 indicating that

λ at burned leks decreased approximately 16 (95 CRI =

071 to 098) relative to λ at unburned leks following theRush Fire Moreover approximately 985 of the posteriordistribution of the ratio estimate was lt1 indicating substan-tial evidence of negative rate of change (Fig 3) CI measures

indicate that the observed change in λ after the Rush Fire

was largely due to a change in λ at the burned leks (CI-con-tribution = 014 95 CRI = minus001 to 026) with moderate

evidence of λ between burned and unburned leks be-coming more similar after the Rush Fire (median CI-divergence = minus004 95 CRI = minus015 to 007)

DiscussionAssessing the impacts of disturbance on wildlife popula-tions is a cornerstone of wildlife conservation We evalu-ated the localized impacts of wildfire a dynamicdisturbance type that is central to management and con-servation of sage-grouse in the Great Basin (Miller et al2011 US Fish and Wildlife Service 2015 Coates et al2016) Using a robust time series of lek counts that tookplace before and after a major wildfire event we wereable to isolate the influence that a specific wildfire eventhad on the local sage-grouse population by making useof a BACIP experimental design within a Bayesian hier-archical SSM framework Sage-grouse populations ex-press cyclical patterns (ranging in duration from 10 to12 years Row and Fedy 2017) and are strongly corre-lated with annual changes in precipitation (Coates et al2018) Yet these potential confounding influences canbe accounted for by measuring the responses of sage-grouse within the same sub-populations before and afterwildfire while contrasting responses inside and outsideburned areas Applying this concept within the BACIframework (Conner et al 2016) we observed strong evi-

dence (985 probability) of negative change in λ atsage-grouse leks affected by a large wildfire relative toleks that occurred outside the fire perimeter (ie not af-

fected) After the fire λ for leks located within the fireperimeter declined by approximately 16 relative tocontrol leks which was based on minimal changes ob-served at those leks located outside the fire perimeter

(median λ before fire = 097 median λ after fire = 095)Our results indicate a meaningful shift in local sage-grouse

population dynamics following wildfire The mean λ ratio ofimpact to control before the fire was gt1 (Fig 2C) meaning

that λ inside the fire perimeter was higher than λ outside

the fire perimeter (pre fire) After the fire the mean λ ratio

was lt1 (Fig 2D) meaning that λ inside the fire perimeter

was lower than λ outside the fire perimeter (post fire)Based on the CI-contribution measure the observed

change in λ ratio in the wake of the Rush Fire was largely

due to a change in λ at burned leks and the degree of dis-

similarity in λ among burned and unburned leks de-

creased (ieλ at burned and unburned leks became moresimilar) over the same time period One explanation forthis shift is that habitat conditions prior to wildfire werebetter within the burn perimeter than the more peripheral

Dudley et al Fire Ecology (2021) 1715 Page 7 of 13

habitat outside the burn resulting in superior sage-grousepopulation performance Following the fire howeverhabitat conditions were apparently degraded such thatsage-grouse population responses were no longer superiorwithin the burned area with negative instead of positivetrends in growth rate This change in the BACI ratiocoupled with a now declining population at leks that

burned suggests that localized extirpation within theBuffalo-Skedaddle PMU is a threat to this relatively iso-lated population Sage-grouse populations on the periph-ery of the species distribution such as the population inthe Buffalo-Skedaddle PMU may be at least partiallydependent on dispersal from more interior populationssuggesting implications for the maintenance of lek

Fig 2 Estimated annual population growth rate (λ) of greater sage-grouse (Centrocercus urophasianus) leks (A) before (2007 to 2008 2011 to

2012) and (B) after (2012 to 2013 2017 to 2018) wildfire and ratios of the estimated annual population growth rates (λ) (C) before fire and (D)after fire in burned areas to unburned areas for each year (blue line) and the mean of the ratios (dashed yellow line) for the Rush Fire in LassenCounty California and Washoe County Nevada USA Shaded polygons represent the 95 credible interval limits The vertical line represents theseparation of growth rates in terms of period (before versus after) assignment The horizontal dashed line represents value of 1 for both ratios

Dudley et al Fire Ecology (2021) 1715 Page 8 of 13

connectivity (Knick and Hanser 2011 Knick et al 2013Row et al 2018) The Rush Fire may have isolated thislocal population from more interior and southern popula-tions by fragmenting habitat thereby leading to reducedconnectivity and subsequent short-term population de-cline If declines are not curbed by habitat restoration orrapid recovery efforts (Ricca and Coates 2020) acute long-term impacts become increasingly likely especially consid-ering natural recovery rates of a decade or more for mostsagebrush communities (Pilliod et al 2017 Pyke et al2020)We found that overall population growth was reduced

following wildfire Wildfire can have a variety of impactson the demographics of local sage-grouse populationswhich has been demonstrated in several study regionsand suggests mechanisms for the population declinesthat we observed at the Buffalo-Skedaddle PMU TheRush Fire occurred in August 2012 which implied thatmost if not all hatch-yearsage-grouse chicks were mo-bile and flighted decreasing the likelihood of direct mor-tality caused by fire However the Rush Fire burnedapproximately 80 to 90 of the vegetation within thewildfire perimeter (Bureau of Land Management 2012)Fall and winter resources were likely substantially af-fected because wildfire kills sagebrush which otherwise

provides critical forage and cover for sage-grouse duringthe winter season (Connelly et al 2011b Miller et al2013) For example substantial reductions in wintersurvival were documented following a large wildfire inOregon USA (Foster 2016) Moreover nesting vegeta-tion was severely affected which likely contributed tolow nest survival documented after the fire between2015 and 2018 (Dudley 2020) After the wildfire sage-grouse used a higher percent of non-shrub nest cover in-side the fire perimeter (eg perennial grasses and forbs)than outside the perimeter (Dudley 2020) Increasedhabitat edge by way of fragmentation of sagebrush com-munities may also increase the occupancy and density ofvisual nest predators such as common ravens (Corvuscorax Linnaeus 1758 Howe et al 2014 OrsquoNeil et al2018 Coates et al 2020) with greater potential impactswhere shrub cover has been reduced (Coates and Dele-hanty 2010) Sage-grouse chicks require habitat that pro-vides both cover and foraging opportunity which can becharacterized by a shrub overstory and herbaceousunderstory with an abundance of insects (Connelly et al2011b Blomberg et al 2013b Gibson et al 2017) Nativeplant communities including shrub overstory may bereplaced by annual grasses after wildfire (Chamberset al 2007 Beck et al 2009 Miller et al 2013 Chamberset al 2014) Such habitat conversion can also negativelyaffect insect abundance (Beck et al 2012) Rhodes et al(2010) found that fire reduced the abundance of ants(Hymenoptera) an important food source for youngsage-grouse chicks While the Rush Fire occurred aftercritical nesting and brood rearing seasons in 2012 thelocal sage-grouse populations were likely subject tolong-term seasonal indirect effects through impacts oncover and food resources and could have lasting effectson the sagebrush community in areas of low ecosystemresistance and resilience (Miller et al 2011 Chamberset al 2014 Coates et al 2016) Continued assessmentsof the sage-grouse demographic responses in this regionare needed to inform post-fire mechanisms contributingto population declineThe extent of large-scale wildfires can exceed the

range of movements exhibited by typical sage-grousepopulations which may constrain adaptive behaviorssuch as nest foraging and lead to maladaptive selectionpatterns (Remeš 2000 ONeil et al 2020) Before theRush Fire female sage-grouse nested on average 37 km(SD = 29) from the nearest lek (Davis et al 2014) whichis significantly less than the average distance betweenthe fire perimeter edge and affected leks used in thisanalysis (mean = 47 km range = 02 to 90 km) Hensthat continue to attend fire-affected leks are less likely toaccess resources and nest beyond the fire perimeter dueto strong patterns of site fidelity (Connelly et al 2011a)and may instead settle in sub-optimal habitats that

Fig 3 Distribution of relative change in population growth rate (λ)of greater sage-grouse (Centrocercus urophasianus) leks in LassenCounty California and Washoe County Nevada USA from beforethe Rush Fire (2007 to 2008 2011 to 2012) to after the Rush Fire(2012 to 2013 2017 to 2018) Relative change below 1 (black

vertical line) indicates a decrease of λ for leks in impact areas(burned) relative to control (unburned) areas after the Rush Fire

whereas relative change above 1 indicates an increase of λ for leksin impact areas relative to control area The percentage of theposterior distribution falling below 1 is indicated by yellow shadingin the legend while the percentage occurring above 1 is indicatedby green shading

Dudley et al Fire Ecology (2021) 1715 Page 9 of 13

contribute to poor performance (Battin 2004) Islands ofunburned habitat could provide partial refuge for sage-grouse occupying areas affected by wildfire (Steenvoordenet al 2019) which could prove to be important in areaswhere sage-grouse exhibit high degrees of site fidelityHowever it is unlikely that habitat in the form of islandscould fully compensate for potential population declinesfollowing fire Although further investigation is needed in-tact sagebrush islands appeared to be sparse within ourstudy area based on estimated loss of native plant commu-nities loss (Bureau of Land Management 2012) and typeconversion to cheatgrass approximately eight yearsfollowing the wildfire (Dudley 2020)Our findings are consistent with several studies show-

ing population impacts on sage-grouse following a majorwildfire event A simulation analysis conducted byPedersen et al (2003) found that under most scenariosfire resulted in reduced sage-grouse populations some-times leading to local population extirpation Resultsfrom Smith and Beck (2018) also demonstrated thatwildfire was associated with immediate and enduring ad-verse impacts on sage-grouse population change suchthat growth rates were reduced for up to 11 years postwildfire In the Great Basin sage-grouse populationswere predicted to decline 57 by 2044 if current annualgrassndashwildfire cycle trends continued (Coates et al2016) The results from our analysis are consistent withthose findings and provide a pattern-based case studythat demonstrates reductions in population size and sug-gests a potential mechanism for species range contrac-tion that can occur when peripheral populations areaffected (eg Coates et al 2019) Although not investi-gated as part of this study reductions in population sizefollowing wildfire are likely a function of reduced ratesof survival and recruitment (Foster et al 2019 Anthony2020 Dudley 2020) as well as potential emigration awayfrom affected areas Additional demographic studies areneeded to identify mechanisms by which wildfire influ-ences population dynamics and the long-term preva-lence of such negative effects

ConclusionsThis study contributes additional evidence that wildfirehas short-term negative impacts on sage-grouse popula-tions Long-term impacts are also likely given the timerequired for sagebrush communities to recover coupledwith the existing threat of permanent state transitions toannual grassland associated with a grassndashfire feedbackcycle (Balch et al 2013 Coates et al 2016 Shriver et al2019) Continued monitoring of wildfire-affected popula-tions is warranted as lingering wildfire effects may re-duce habitat quality and population capacity over anextended period (Coates et al 2016) In addition im-pacts to other sagebrush ecosystem species need

investigation to understand community-wide impacts onspecies diversity Active restoration efforts that facilitatesagebrush regrowth while providing short-term coverand resources for nesting and winter foraging (Pykeet al 2020 Ricca and Coates 2020) may be required tosustain local populations following increasingly frequentwildfire events affecting sage-grouse habitat across theextent of its range

AcknowledgementsWe thank R Croston K Miller and T Kimball for providing helpful commentsthat improved this manuscript This research was supported by funding fromthe California Department of Fish and Wildlife (CDFW) Bureau of LandManagement (BLM) and US Geological Survey (USGS) Collection of fielddata was supported by multiple federal and state agencies including CDFWBLM USGS Idaho State University and University of Idaho We areparticularly grateful to M Ricca (USGS) J Atkinson (USGS) R Kelble (USGS) JSeverson (USGS) S Mathews (USGS) A Johnson (BLM) K Miller (CDFW) andK Collum (BLM) for their contributions to field study logistics data andconceptual design We thank numerous technicians who helped conduct lekcounts Any use of trade firm or product names is for descriptive purposesonly and does not imply endorsement by the US Government

Authorsrsquo contributionsIn alphabetical order of last name PSC and DJD conceived idea anddesign IFD and SCG collected the data BGP IFD and STO analyzedthe data PSC DJD IFD SCG STO and BGP wrote and edited themanuscript PSC DJD and SCG contributed resources and funding Allauthors read and approved the final manuscript

FundingThis research was conducted under grants from California Department ofFish and Wildlife Bureau of Land Management and US Geological Survey

Availability of data and materialsThe data that support the findings of this study are available from CaliforniaDepartment of Fish and Wildlife but restrictions apply to the availability ofthese data which were used under license for the current study and so arenot publicly available Data are however available from the authors uponreasonable request and with permission of California Department of Fish andWildlife

Declarations

Ethics approval and consent to participateNot applicable

Consent for publicationNot applicable

Competing interestsThe authors declare that they have no competing interests

Author details1US Geological Survey Western Ecological Research Center Dixon FieldStation 800 Business Park Drive Suite D Dixon California 95620 USA2Department of Biological Sciences Idaho State University 921 South 8thAvenue Pocatello Idaho 83209 USA 3California Department of Fish andWildlife 1010 Riverside Parkway West Sacramento California 95605 USA

Received 28 July 2020 Accepted 9 March 2021

ReferencesAnthony CR 2020 Thermal ecology and population dynamics of female greater

sage-grouse following wildfire in the Trout Creek Mountains of Oregon andNevada Dissertation Corvallis USA Oregon State University

Armentrout DJ and F Hall 2005 Conservation strategy for sage-grouse(Centrocercus urophasianus) and sagebrush ecosystems within the Buffalo-

Dudley et al Fire Ecology (2021) 1715 Page 10 of 13

Skedaddle Population Management Unit Susanville Bureau of LandManagement Eagle Lake Field Office

Baker WL 2006 Fire and restoration of sagebrush ecosystems Wildlife SocietyBulletin 34 (1) 177ndash185 httpsdoiorg1021930091-7648(2006)34[177FAROSE]20CO2

Balch JK BA Bradley CM DrsquoAntonio and J Goacutemez-Dans 2013 Introducedannual grass increases regional fire activity across the arid western USA(1980-2009) Global Change Biology 19 (1) 173ndash183 httpsdoiorg101111gcb12046

Baruch-Mordo S JS Evans JP Severson DE Naugle JD Maestas JM Kiesecker MJ Falkowski CA Hagen and KP Reese 2013 Saving sage-grouse from the treesa proactive solution to reducing a key threat to a candidate species BiologicalConservation 167 233ndash241 httpsdoiorg101016jbiocon201308017

Battin J 2004 When good animals love bad habitats ecological traps and theconservation of animal populations Conservation Biology 18 (6) 1482ndash1491httpsdoiorg101111j1523-1739200400417x

Beck JL JW Connelly and KP Reese 2009 Recovery of greater sage-grousehabitat features in Wyoming big sagebrush following prescribed fire RestorationEcology 17 (3) 393ndash403 httpsdoiorg101111j1526-100X200800380x

Beck JL JW Connelly and CL Wambolt 2012 Consequences of treatingWyoming big sagebrush to enhance wildlife habitats Rangeland Ecology ampManagement 65 (5) 444ndash455 httpsdoiorg102111REM-D-10-001231

Blomberg E and C Hagen 2020 How many leks does it take Minimumsamples sizes for measuring local-scale conservation outcomes in greatersage-grouse Avian Conservation and Ecology 15 9 httpsdoiorg105751ACE-01517-150109

Blomberg EJ SR Poulson JS Sedinger and D Gibson 2013b Prefledging diet iscorrelated with individual growth in greater sage-grouse (Centrocercusurophasianus) The Auk 130 (4) 715ndash724 httpsdoiorg101525auk201312188

Blomberg EJ JS Sedinger DV Nonne and MT Atamian 2013a Annual malelek attendance influences count-based population indices of greater sage-grouse The Journal of Wildlife Management 77 (8) 1583ndash1592 httpsdoiorg101002jwmg615

Brooks ML CM DrsquoAntonio DM Richardson JB Grace JE Keeley JMDiTomaso RJ Hobbs M Pellant and D Pyke 2004 Effects of invasive alienplants on fire regimes BioScience 54 (7) 677ndash688 httpsdoiorg1016410006-3568(2004)054[0677EOIAPO]20CO2

Brooks ML JR Matchett DJ Shinneman and PS Coates 2015 Fire patterns inthe range of greater sage-grouse 1984-2013 implications for conservationand management In US Geological Survey Open-File Report 2015-1167 RestonUS Geological Survey httpsdoiorg103133ofr20151167

Bunting SC BM Kilgore and CL Bushey 1987 Guidelines for prescribedburning sagebrush-grass rangelands in the northern Great Basin In USDAGeneral Technical Report INT-GTR-231 Ogden USDA Forest ServiceIntermountain Research Station httpsdoiorg102737INT-GTR-231

Bureau of Land Management 2012 Environmental assessment Rush Fireemergency stabilization and rehabilitation DOI-BLM-CA-N050-2012-45-EASusanville Bureau of Land Management Eagle Lake Field Office

Carroll JM TJ Hovick CA Davis RD Elmore and SD Fuhlendorf 2017Reproductive plasticity and landscape heterogeneity benefit a ground-nesting bird in a fire-prone ecosystem Ecological Applications 27 (7) 2234ndash2244 httpsdoiorg101002eap1604

Chambers JC BA Bradley CS Brown C DrsquoAntonio MJ Germino JB Grace SPHardegree RF Miller and DA Pyke 2014 Resilience to stress anddisturbance and resistance to Bromus tectorum L invasion in cold desertshrublands of western North America Ecosystems 17 (2) 360ndash375 httpsdoiorg101007s10021-013-9725-5

Chambers JC BA Roundy RR Blank SE Meyer and A Whittaker 2007 Whatmakes Great Basin sagebrush ecosystems invasible by Bromus tectorumEcological Monographs 77 (1) 117ndash145 httpsdoiorg10189005-1991

Chevalier M JC Russell and J Knape 2019 New measures for evaluation ofenvironmental perturbations using Before-After-Control-Impact analysesEcological Applications 29 (2) e01838 httpsdoiorg101002eap1838

Coates PS and DJ Delehanty 2010 Nest predation of greater sage-grouse inrelation to microhabitat factors and predators Journal of WildlifeManagement 74 (2) 240ndash248 httpsdoiorg1021932009-047

Coates PS ST OrsquoNeil BE Brussee MA Ricca PJ Jackson JB Dinkins KBHowe AM Moser LJ Foster and DJ Delehanty 2020 Broad-scale impactsof an invasive native predator on a sensitive native prey species within theshifting avian community of the North American Great Basin BiologicalConservation 243 article108409 httpsdoiorg101016jbiocon2020108409

Coates PS BG Prochazka MA Ricca BJ Halstead ML Casazza EJ Blomberg BEBrussee L Wiechman J Tebbenkamp SC Gardner and KP Reese 2018 Therelative importance of intrinsic and extrinsic drivers to population growth varyamong local populations of greater sage-grouse an integrated populationmodeling approach Auk 135 (2) 240ndash261 httpsdoiorg101642AUK-17-1371

Coates PS MA Ricca BG Prochazka ML Brooks KE Doherty T Kroger EJBlomberg CA Hagen and ML Casazza 2016 Wildfire climate and invasivegrass interactions negatively impact an indicator species by reshapingsagebrush ecosystems Proceedings of the National Academy of Sciences 113(45) 12745ndash12750 httpsdoiorg101073pnas1606898113

Coates PS MA Ricca BG Prochazka ST OrsquoNeil JP Severson SR Mathews SEspinosa S Gardner S Lisius and DJ Delehanty 2019 Population andhabitat analyses for greater sage-grouse (Centrocercus urophasianus) in thebi-state distinct population segment 2018 update In US Geological SurveyOpen-File Report 2019-1149 Reston U S Geological Survey httpsdoiorg103133ofr20191149

Connelly JW CA Hagen and MA Schroeder 2011a Characteristics anddynamics of greater sage-grouse populations In Greater sage-grouse ecologyand conservation of a landscape species and its habitats ed ST Knick and JW Connelly 53ndash67 Berkeley University of California Press httpsdoiorg101525california97805202671140030004

Connelly JW ST Knick CE Braun WL Baker EA Beever TJ Christiansen KEDoherty EO Garton CA Hagen SE Hanser DH Johnson M Leu RF MillerDE Naugle SJ Oyler-McCance DA Pyke KP Reese MA Schroeder SJStiver BL Walker and MJ Wisdom 2011b Conservation of greater sage-grousemdasha synthesis of current trends and future management In Greatersage-grouse ecology and conservation of a landscape species and its habitatsed ST Knick and JW Connelly 549ndash563 Berkeley University of CaliforniaPress httpsdoiorg101525california97805202671140030025

Connelly JW KP Reese and MA Schroeder 2003 Monitoring of greater sage-grouse habitats and populations Station bulletin 80 Moscow Idaho Universityof Idaho College of Natural Resources Experiment Station httpsdoiorg105962bhltitle153828

Connelly JW and MA Schroeder 2007 Historical and current approaches tomonitoring greater sage-grouse In Proceedings of a symposium monitoringpopulations of sage-grouse Station bulletin 88 ed KP Reese and RT Bowyer3ndash9 Moscow Idaho University of Idaho College of Natural ResourcesExperiment Station

Connelly JW MA Schroeder AR Sands and CE Braun 2000 Guidelines tomanage sage grouse populations and their habitats Wildlife Society Bulletin28 967ndash985

Conner MM WC Saunders N Bouwes and C Jordan 2016 Evaluating impactsusing a BACI design ratios and a Bayesian approach with a focus onrestoration Environmental Monitoring and Assessment 188 (10) 555 httpsdoiorg101007s10661-016-5526-6

DrsquoAntonio CM and PM Vitousek 1992 Biological invasions by exotic grasses thegrassfire cycle and global change Annual Review of Ecology and Systematics 23(1) 63ndash87 httpsdoiorg101146annureves23110192000431

Davis DM and JA Crawford 2015 Case study short-term response of greatersage-grouse habitats to wildfire in mountain big sagebrush communitiesWildlife Society Bulletin 39 (1) 129ndash137 httpsdoiorg101002wsb505

Davis DM KP Reese and SC Gardner 2014 Diurnal space use and seasonalmovement patterns of greater sage-grouse in northeastern California WildlifeSociety Bulletin 38 (4) 710ndash720 httpsdoiorg101002wsb467

Doherty KE JS Evans PS Coates LM Juliusson and BC Fedy 2016Importance of regional variation in conservation planning a rangewideexample of the greater sage-grouse Ecosphere 7 (10) 1ndash27 httpsdoiorg101002ecs21462

Dudley IF 2020 Maladaptive nest site selection and reduced nest survival in femalesage-grouse following wildfire Thesis Pocatello USA Idaho State University

Eidenshink J B Schwind K Brewer ZL Zhu B Quayle and S Howard 2007 Aproject for monitoring trends in burn severity Fire Ecology 3 (1) 3ndash22 httpsdoiorg104996fireecology0301003

Fischer RA AD Apa WL Wakkinen KP Reese and JW Connelly 1993Nesting-area fidelity of sage grouse in southeastern Idaho Condor 95 (4)1038ndash1041 httpsdoiorg1023071369442

Foster LJ 2016 Resource selection and demographic rats of female sage-grousefollowing large-scale wildfire Thesis Corvallis USA Oregon State University

Foster LJ KM Dugger CA Hagen and DA Budeau 2019 Greater sage-grousevital rates after wildfire Journal of Wildlife Management 83 (1) 121ndash134httpsdoiorg101002jwmg21573

Dudley et al Fire Ecology (2021) 1715 Page 11 of 13

habitat outside the burn resulting in superior sage-grousepopulation performance Following the fire howeverhabitat conditions were apparently degraded such thatsage-grouse population responses were no longer superiorwithin the burned area with negative instead of positivetrends in growth rate This change in the BACI ratiocoupled with a now declining population at leks that

burned suggests that localized extirpation within theBuffalo-Skedaddle PMU is a threat to this relatively iso-lated population Sage-grouse populations on the periph-ery of the species distribution such as the population inthe Buffalo-Skedaddle PMU may be at least partiallydependent on dispersal from more interior populationssuggesting implications for the maintenance of lek

Fig 2 Estimated annual population growth rate (λ) of greater sage-grouse (Centrocercus urophasianus) leks (A) before (2007 to 2008 2011 to

2012) and (B) after (2012 to 2013 2017 to 2018) wildfire and ratios of the estimated annual population growth rates (λ) (C) before fire and (D)after fire in burned areas to unburned areas for each year (blue line) and the mean of the ratios (dashed yellow line) for the Rush Fire in LassenCounty California and Washoe County Nevada USA Shaded polygons represent the 95 credible interval limits The vertical line represents theseparation of growth rates in terms of period (before versus after) assignment The horizontal dashed line represents value of 1 for both ratios

Dudley et al Fire Ecology (2021) 1715 Page 8 of 13

connectivity (Knick and Hanser 2011 Knick et al 2013Row et al 2018) The Rush Fire may have isolated thislocal population from more interior and southern popula-tions by fragmenting habitat thereby leading to reducedconnectivity and subsequent short-term population de-cline If declines are not curbed by habitat restoration orrapid recovery efforts (Ricca and Coates 2020) acute long-term impacts become increasingly likely especially consid-ering natural recovery rates of a decade or more for mostsagebrush communities (Pilliod et al 2017 Pyke et al2020)We found that overall population growth was reduced

following wildfire Wildfire can have a variety of impactson the demographics of local sage-grouse populationswhich has been demonstrated in several study regionsand suggests mechanisms for the population declinesthat we observed at the Buffalo-Skedaddle PMU TheRush Fire occurred in August 2012 which implied thatmost if not all hatch-yearsage-grouse chicks were mo-bile and flighted decreasing the likelihood of direct mor-tality caused by fire However the Rush Fire burnedapproximately 80 to 90 of the vegetation within thewildfire perimeter (Bureau of Land Management 2012)Fall and winter resources were likely substantially af-fected because wildfire kills sagebrush which otherwise

provides critical forage and cover for sage-grouse duringthe winter season (Connelly et al 2011b Miller et al2013) For example substantial reductions in wintersurvival were documented following a large wildfire inOregon USA (Foster 2016) Moreover nesting vegeta-tion was severely affected which likely contributed tolow nest survival documented after the fire between2015 and 2018 (Dudley 2020) After the wildfire sage-grouse used a higher percent of non-shrub nest cover in-side the fire perimeter (eg perennial grasses and forbs)than outside the perimeter (Dudley 2020) Increasedhabitat edge by way of fragmentation of sagebrush com-munities may also increase the occupancy and density ofvisual nest predators such as common ravens (Corvuscorax Linnaeus 1758 Howe et al 2014 OrsquoNeil et al2018 Coates et al 2020) with greater potential impactswhere shrub cover has been reduced (Coates and Dele-hanty 2010) Sage-grouse chicks require habitat that pro-vides both cover and foraging opportunity which can becharacterized by a shrub overstory and herbaceousunderstory with an abundance of insects (Connelly et al2011b Blomberg et al 2013b Gibson et al 2017) Nativeplant communities including shrub overstory may bereplaced by annual grasses after wildfire (Chamberset al 2007 Beck et al 2009 Miller et al 2013 Chamberset al 2014) Such habitat conversion can also negativelyaffect insect abundance (Beck et al 2012) Rhodes et al(2010) found that fire reduced the abundance of ants(Hymenoptera) an important food source for youngsage-grouse chicks While the Rush Fire occurred aftercritical nesting and brood rearing seasons in 2012 thelocal sage-grouse populations were likely subject tolong-term seasonal indirect effects through impacts oncover and food resources and could have lasting effectson the sagebrush community in areas of low ecosystemresistance and resilience (Miller et al 2011 Chamberset al 2014 Coates et al 2016) Continued assessmentsof the sage-grouse demographic responses in this regionare needed to inform post-fire mechanisms contributingto population declineThe extent of large-scale wildfires can exceed the

range of movements exhibited by typical sage-grousepopulations which may constrain adaptive behaviorssuch as nest foraging and lead to maladaptive selectionpatterns (Remeš 2000 ONeil et al 2020) Before theRush Fire female sage-grouse nested on average 37 km(SD = 29) from the nearest lek (Davis et al 2014) whichis significantly less than the average distance betweenthe fire perimeter edge and affected leks used in thisanalysis (mean = 47 km range = 02 to 90 km) Hensthat continue to attend fire-affected leks are less likely toaccess resources and nest beyond the fire perimeter dueto strong patterns of site fidelity (Connelly et al 2011a)and may instead settle in sub-optimal habitats that

Fig 3 Distribution of relative change in population growth rate (λ)of greater sage-grouse (Centrocercus urophasianus) leks in LassenCounty California and Washoe County Nevada USA from beforethe Rush Fire (2007 to 2008 2011 to 2012) to after the Rush Fire(2012 to 2013 2017 to 2018) Relative change below 1 (black

vertical line) indicates a decrease of λ for leks in impact areas(burned) relative to control (unburned) areas after the Rush Fire

whereas relative change above 1 indicates an increase of λ for leksin impact areas relative to control area The percentage of theposterior distribution falling below 1 is indicated by yellow shadingin the legend while the percentage occurring above 1 is indicatedby green shading

Dudley et al Fire Ecology (2021) 1715 Page 9 of 13

contribute to poor performance (Battin 2004) Islands ofunburned habitat could provide partial refuge for sage-grouse occupying areas affected by wildfire (Steenvoordenet al 2019) which could prove to be important in areaswhere sage-grouse exhibit high degrees of site fidelityHowever it is unlikely that habitat in the form of islandscould fully compensate for potential population declinesfollowing fire Although further investigation is needed in-tact sagebrush islands appeared to be sparse within ourstudy area based on estimated loss of native plant commu-nities loss (Bureau of Land Management 2012) and typeconversion to cheatgrass approximately eight yearsfollowing the wildfire (Dudley 2020)Our findings are consistent with several studies show-

ing population impacts on sage-grouse following a majorwildfire event A simulation analysis conducted byPedersen et al (2003) found that under most scenariosfire resulted in reduced sage-grouse populations some-times leading to local population extirpation Resultsfrom Smith and Beck (2018) also demonstrated thatwildfire was associated with immediate and enduring ad-verse impacts on sage-grouse population change suchthat growth rates were reduced for up to 11 years postwildfire In the Great Basin sage-grouse populationswere predicted to decline 57 by 2044 if current annualgrassndashwildfire cycle trends continued (Coates et al2016) The results from our analysis are consistent withthose findings and provide a pattern-based case studythat demonstrates reductions in population size and sug-gests a potential mechanism for species range contrac-tion that can occur when peripheral populations areaffected (eg Coates et al 2019) Although not investi-gated as part of this study reductions in population sizefollowing wildfire are likely a function of reduced ratesof survival and recruitment (Foster et al 2019 Anthony2020 Dudley 2020) as well as potential emigration awayfrom affected areas Additional demographic studies areneeded to identify mechanisms by which wildfire influ-ences population dynamics and the long-term preva-lence of such negative effects

ConclusionsThis study contributes additional evidence that wildfirehas short-term negative impacts on sage-grouse popula-tions Long-term impacts are also likely given the timerequired for sagebrush communities to recover coupledwith the existing threat of permanent state transitions toannual grassland associated with a grassndashfire feedbackcycle (Balch et al 2013 Coates et al 2016 Shriver et al2019) Continued monitoring of wildfire-affected popula-tions is warranted as lingering wildfire effects may re-duce habitat quality and population capacity over anextended period (Coates et al 2016) In addition im-pacts to other sagebrush ecosystem species need

investigation to understand community-wide impacts onspecies diversity Active restoration efforts that facilitatesagebrush regrowth while providing short-term coverand resources for nesting and winter foraging (Pykeet al 2020 Ricca and Coates 2020) may be required tosustain local populations following increasingly frequentwildfire events affecting sage-grouse habitat across theextent of its range

AcknowledgementsWe thank R Croston K Miller and T Kimball for providing helpful commentsthat improved this manuscript This research was supported by funding fromthe California Department of Fish and Wildlife (CDFW) Bureau of LandManagement (BLM) and US Geological Survey (USGS) Collection of fielddata was supported by multiple federal and state agencies including CDFWBLM USGS Idaho State University and University of Idaho We areparticularly grateful to M Ricca (USGS) J Atkinson (USGS) R Kelble (USGS) JSeverson (USGS) S Mathews (USGS) A Johnson (BLM) K Miller (CDFW) andK Collum (BLM) for their contributions to field study logistics data andconceptual design We thank numerous technicians who helped conduct lekcounts Any use of trade firm or product names is for descriptive purposesonly and does not imply endorsement by the US Government

Authorsrsquo contributionsIn alphabetical order of last name PSC and DJD conceived idea anddesign IFD and SCG collected the data BGP IFD and STO analyzedthe data PSC DJD IFD SCG STO and BGP wrote and edited themanuscript PSC DJD and SCG contributed resources and funding Allauthors read and approved the final manuscript

FundingThis research was conducted under grants from California Department ofFish and Wildlife Bureau of Land Management and US Geological Survey

Availability of data and materialsThe data that support the findings of this study are available from CaliforniaDepartment of Fish and Wildlife but restrictions apply to the availability ofthese data which were used under license for the current study and so arenot publicly available Data are however available from the authors uponreasonable request and with permission of California Department of Fish andWildlife

Declarations

Ethics approval and consent to participateNot applicable

Consent for publicationNot applicable

Competing interestsThe authors declare that they have no competing interests

Author details1US Geological Survey Western Ecological Research Center Dixon FieldStation 800 Business Park Drive Suite D Dixon California 95620 USA2Department of Biological Sciences Idaho State University 921 South 8thAvenue Pocatello Idaho 83209 USA 3California Department of Fish andWildlife 1010 Riverside Parkway West Sacramento California 95605 USA

Received 28 July 2020 Accepted 9 March 2021

ReferencesAnthony CR 2020 Thermal ecology and population dynamics of female greater

sage-grouse following wildfire in the Trout Creek Mountains of Oregon andNevada Dissertation Corvallis USA Oregon State University

Armentrout DJ and F Hall 2005 Conservation strategy for sage-grouse(Centrocercus urophasianus) and sagebrush ecosystems within the Buffalo-

Dudley et al Fire Ecology (2021) 1715 Page 10 of 13

Skedaddle Population Management Unit Susanville Bureau of LandManagement Eagle Lake Field Office

Baker WL 2006 Fire and restoration of sagebrush ecosystems Wildlife SocietyBulletin 34 (1) 177ndash185 httpsdoiorg1021930091-7648(2006)34[177FAROSE]20CO2

Balch JK BA Bradley CM DrsquoAntonio and J Goacutemez-Dans 2013 Introducedannual grass increases regional fire activity across the arid western USA(1980-2009) Global Change Biology 19 (1) 173ndash183 httpsdoiorg101111gcb12046

Baruch-Mordo S JS Evans JP Severson DE Naugle JD Maestas JM Kiesecker MJ Falkowski CA Hagen and KP Reese 2013 Saving sage-grouse from the treesa proactive solution to reducing a key threat to a candidate species BiologicalConservation 167 233ndash241 httpsdoiorg101016jbiocon201308017

Battin J 2004 When good animals love bad habitats ecological traps and theconservation of animal populations Conservation Biology 18 (6) 1482ndash1491httpsdoiorg101111j1523-1739200400417x

Beck JL JW Connelly and KP Reese 2009 Recovery of greater sage-grousehabitat features in Wyoming big sagebrush following prescribed fire RestorationEcology 17 (3) 393ndash403 httpsdoiorg101111j1526-100X200800380x

Beck JL JW Connelly and CL Wambolt 2012 Consequences of treatingWyoming big sagebrush to enhance wildlife habitats Rangeland Ecology ampManagement 65 (5) 444ndash455 httpsdoiorg102111REM-D-10-001231

Blomberg E and C Hagen 2020 How many leks does it take Minimumsamples sizes for measuring local-scale conservation outcomes in greatersage-grouse Avian Conservation and Ecology 15 9 httpsdoiorg105751ACE-01517-150109

Blomberg EJ SR Poulson JS Sedinger and D Gibson 2013b Prefledging diet iscorrelated with individual growth in greater sage-grouse (Centrocercusurophasianus) The Auk 130 (4) 715ndash724 httpsdoiorg101525auk201312188

Blomberg EJ JS Sedinger DV Nonne and MT Atamian 2013a Annual malelek attendance influences count-based population indices of greater sage-grouse The Journal of Wildlife Management 77 (8) 1583ndash1592 httpsdoiorg101002jwmg615

Brooks ML CM DrsquoAntonio DM Richardson JB Grace JE Keeley JMDiTomaso RJ Hobbs M Pellant and D Pyke 2004 Effects of invasive alienplants on fire regimes BioScience 54 (7) 677ndash688 httpsdoiorg1016410006-3568(2004)054[0677EOIAPO]20CO2

Brooks ML JR Matchett DJ Shinneman and PS Coates 2015 Fire patterns inthe range of greater sage-grouse 1984-2013 implications for conservationand management In US Geological Survey Open-File Report 2015-1167 RestonUS Geological Survey httpsdoiorg103133ofr20151167

Bunting SC BM Kilgore and CL Bushey 1987 Guidelines for prescribedburning sagebrush-grass rangelands in the northern Great Basin In USDAGeneral Technical Report INT-GTR-231 Ogden USDA Forest ServiceIntermountain Research Station httpsdoiorg102737INT-GTR-231

Bureau of Land Management 2012 Environmental assessment Rush Fireemergency stabilization and rehabilitation DOI-BLM-CA-N050-2012-45-EASusanville Bureau of Land Management Eagle Lake Field Office

Carroll JM TJ Hovick CA Davis RD Elmore and SD Fuhlendorf 2017Reproductive plasticity and landscape heterogeneity benefit a ground-nesting bird in a fire-prone ecosystem Ecological Applications 27 (7) 2234ndash2244 httpsdoiorg101002eap1604

Chambers JC BA Bradley CS Brown C DrsquoAntonio MJ Germino JB Grace SPHardegree RF Miller and DA Pyke 2014 Resilience to stress anddisturbance and resistance to Bromus tectorum L invasion in cold desertshrublands of western North America Ecosystems 17 (2) 360ndash375 httpsdoiorg101007s10021-013-9725-5

Chambers JC BA Roundy RR Blank SE Meyer and A Whittaker 2007 Whatmakes Great Basin sagebrush ecosystems invasible by Bromus tectorumEcological Monographs 77 (1) 117ndash145 httpsdoiorg10189005-1991

Chevalier M JC Russell and J Knape 2019 New measures for evaluation ofenvironmental perturbations using Before-After-Control-Impact analysesEcological Applications 29 (2) e01838 httpsdoiorg101002eap1838

Coates PS and DJ Delehanty 2010 Nest predation of greater sage-grouse inrelation to microhabitat factors and predators Journal of WildlifeManagement 74 (2) 240ndash248 httpsdoiorg1021932009-047

Coates PS ST OrsquoNeil BE Brussee MA Ricca PJ Jackson JB Dinkins KBHowe AM Moser LJ Foster and DJ Delehanty 2020 Broad-scale impactsof an invasive native predator on a sensitive native prey species within theshifting avian community of the North American Great Basin BiologicalConservation 243 article108409 httpsdoiorg101016jbiocon2020108409

Coates PS BG Prochazka MA Ricca BJ Halstead ML Casazza EJ Blomberg BEBrussee L Wiechman J Tebbenkamp SC Gardner and KP Reese 2018 Therelative importance of intrinsic and extrinsic drivers to population growth varyamong local populations of greater sage-grouse an integrated populationmodeling approach Auk 135 (2) 240ndash261 httpsdoiorg101642AUK-17-1371

Coates PS MA Ricca BG Prochazka ML Brooks KE Doherty T Kroger EJBlomberg CA Hagen and ML Casazza 2016 Wildfire climate and invasivegrass interactions negatively impact an indicator species by reshapingsagebrush ecosystems Proceedings of the National Academy of Sciences 113(45) 12745ndash12750 httpsdoiorg101073pnas1606898113

Coates PS MA Ricca BG Prochazka ST OrsquoNeil JP Severson SR Mathews SEspinosa S Gardner S Lisius and DJ Delehanty 2019 Population andhabitat analyses for greater sage-grouse (Centrocercus urophasianus) in thebi-state distinct population segment 2018 update In US Geological SurveyOpen-File Report 2019-1149 Reston U S Geological Survey httpsdoiorg103133ofr20191149

Connelly JW CA Hagen and MA Schroeder 2011a Characteristics anddynamics of greater sage-grouse populations In Greater sage-grouse ecologyand conservation of a landscape species and its habitats ed ST Knick and JW Connelly 53ndash67 Berkeley University of California Press httpsdoiorg101525california97805202671140030004

Connelly JW ST Knick CE Braun WL Baker EA Beever TJ Christiansen KEDoherty EO Garton CA Hagen SE Hanser DH Johnson M Leu RF MillerDE Naugle SJ Oyler-McCance DA Pyke KP Reese MA Schroeder SJStiver BL Walker and MJ Wisdom 2011b Conservation of greater sage-grousemdasha synthesis of current trends and future management In Greatersage-grouse ecology and conservation of a landscape species and its habitatsed ST Knick and JW Connelly 549ndash563 Berkeley University of CaliforniaPress httpsdoiorg101525california97805202671140030025

Connelly JW KP Reese and MA Schroeder 2003 Monitoring of greater sage-grouse habitats and populations Station bulletin 80 Moscow Idaho Universityof Idaho College of Natural Resources Experiment Station httpsdoiorg105962bhltitle153828

Connelly JW and MA Schroeder 2007 Historical and current approaches tomonitoring greater sage-grouse In Proceedings of a symposium monitoringpopulations of sage-grouse Station bulletin 88 ed KP Reese and RT Bowyer3ndash9 Moscow Idaho University of Idaho College of Natural ResourcesExperiment Station

Connelly JW MA Schroeder AR Sands and CE Braun 2000 Guidelines tomanage sage grouse populations and their habitats Wildlife Society Bulletin28 967ndash985

Conner MM WC Saunders N Bouwes and C Jordan 2016 Evaluating impactsusing a BACI design ratios and a Bayesian approach with a focus onrestoration Environmental Monitoring and Assessment 188 (10) 555 httpsdoiorg101007s10661-016-5526-6

DrsquoAntonio CM and PM Vitousek 1992 Biological invasions by exotic grasses thegrassfire cycle and global change Annual Review of Ecology and Systematics 23(1) 63ndash87 httpsdoiorg101146annureves23110192000431

Davis DM and JA Crawford 2015 Case study short-term response of greatersage-grouse habitats to wildfire in mountain big sagebrush communitiesWildlife Society Bulletin 39 (1) 129ndash137 httpsdoiorg101002wsb505

Davis DM KP Reese and SC Gardner 2014 Diurnal space use and seasonalmovement patterns of greater sage-grouse in northeastern California WildlifeSociety Bulletin 38 (4) 710ndash720 httpsdoiorg101002wsb467

Doherty KE JS Evans PS Coates LM Juliusson and BC Fedy 2016Importance of regional variation in conservation planning a rangewideexample of the greater sage-grouse Ecosphere 7 (10) 1ndash27 httpsdoiorg101002ecs21462

Dudley IF 2020 Maladaptive nest site selection and reduced nest survival in femalesage-grouse following wildfire Thesis Pocatello USA Idaho State University

Eidenshink J B Schwind K Brewer ZL Zhu B Quayle and S Howard 2007 Aproject for monitoring trends in burn severity Fire Ecology 3 (1) 3ndash22 httpsdoiorg104996fireecology0301003

Fischer RA AD Apa WL Wakkinen KP Reese and JW Connelly 1993Nesting-area fidelity of sage grouse in southeastern Idaho Condor 95 (4)1038ndash1041 httpsdoiorg1023071369442

Foster LJ 2016 Resource selection and demographic rats of female sage-grousefollowing large-scale wildfire Thesis Corvallis USA Oregon State University

Foster LJ KM Dugger CA Hagen and DA Budeau 2019 Greater sage-grousevital rates after wildfire Journal of Wildlife Management 83 (1) 121ndash134httpsdoiorg101002jwmg21573

Dudley et al Fire Ecology (2021) 1715 Page 11 of 13

connectivity (Knick and Hanser 2011 Knick et al 2013Row et al 2018) The Rush Fire may have isolated thislocal population from more interior and southern popula-tions by fragmenting habitat thereby leading to reducedconnectivity and subsequent short-term population de-cline If declines are not curbed by habitat restoration orrapid recovery efforts (Ricca and Coates 2020) acute long-term impacts become increasingly likely especially consid-ering natural recovery rates of a decade or more for mostsagebrush communities (Pilliod et al 2017 Pyke et al2020)We found that overall population growth was reduced

following wildfire Wildfire can have a variety of impactson the demographics of local sage-grouse populationswhich has been demonstrated in several study regionsand suggests mechanisms for the population declinesthat we observed at the Buffalo-Skedaddle PMU TheRush Fire occurred in August 2012 which implied thatmost if not all hatch-yearsage-grouse chicks were mo-bile and flighted decreasing the likelihood of direct mor-tality caused by fire However the Rush Fire burnedapproximately 80 to 90 of the vegetation within thewildfire perimeter (Bureau of Land Management 2012)Fall and winter resources were likely substantially af-fected because wildfire kills sagebrush which otherwise

provides critical forage and cover for sage-grouse duringthe winter season (Connelly et al 2011b Miller et al2013) For example substantial reductions in wintersurvival were documented following a large wildfire inOregon USA (Foster 2016) Moreover nesting vegeta-tion was severely affected which likely contributed tolow nest survival documented after the fire between2015 and 2018 (Dudley 2020) After the wildfire sage-grouse used a higher percent of non-shrub nest cover in-side the fire perimeter (eg perennial grasses and forbs)than outside the perimeter (Dudley 2020) Increasedhabitat edge by way of fragmentation of sagebrush com-munities may also increase the occupancy and density ofvisual nest predators such as common ravens (Corvuscorax Linnaeus 1758 Howe et al 2014 OrsquoNeil et al2018 Coates et al 2020) with greater potential impactswhere shrub cover has been reduced (Coates and Dele-hanty 2010) Sage-grouse chicks require habitat that pro-vides both cover and foraging opportunity which can becharacterized by a shrub overstory and herbaceousunderstory with an abundance of insects (Connelly et al2011b Blomberg et al 2013b Gibson et al 2017) Nativeplant communities including shrub overstory may bereplaced by annual grasses after wildfire (Chamberset al 2007 Beck et al 2009 Miller et al 2013 Chamberset al 2014) Such habitat conversion can also negativelyaffect insect abundance (Beck et al 2012) Rhodes et al(2010) found that fire reduced the abundance of ants(Hymenoptera) an important food source for youngsage-grouse chicks While the Rush Fire occurred aftercritical nesting and brood rearing seasons in 2012 thelocal sage-grouse populations were likely subject tolong-term seasonal indirect effects through impacts oncover and food resources and could have lasting effectson the sagebrush community in areas of low ecosystemresistance and resilience (Miller et al 2011 Chamberset al 2014 Coates et al 2016) Continued assessmentsof the sage-grouse demographic responses in this regionare needed to inform post-fire mechanisms contributingto population declineThe extent of large-scale wildfires can exceed the

range of movements exhibited by typical sage-grousepopulations which may constrain adaptive behaviorssuch as nest foraging and lead to maladaptive selectionpatterns (Remeš 2000 ONeil et al 2020) Before theRush Fire female sage-grouse nested on average 37 km(SD = 29) from the nearest lek (Davis et al 2014) whichis significantly less than the average distance betweenthe fire perimeter edge and affected leks used in thisanalysis (mean = 47 km range = 02 to 90 km) Hensthat continue to attend fire-affected leks are less likely toaccess resources and nest beyond the fire perimeter dueto strong patterns of site fidelity (Connelly et al 2011a)and may instead settle in sub-optimal habitats that

Fig 3 Distribution of relative change in population growth rate (λ)of greater sage-grouse (Centrocercus urophasianus) leks in LassenCounty California and Washoe County Nevada USA from beforethe Rush Fire (2007 to 2008 2011 to 2012) to after the Rush Fire(2012 to 2013 2017 to 2018) Relative change below 1 (black

vertical line) indicates a decrease of λ for leks in impact areas(burned) relative to control (unburned) areas after the Rush Fire

whereas relative change above 1 indicates an increase of λ for leksin impact areas relative to control area The percentage of theposterior distribution falling below 1 is indicated by yellow shadingin the legend while the percentage occurring above 1 is indicatedby green shading

Dudley et al Fire Ecology (2021) 1715 Page 9 of 13

contribute to poor performance (Battin 2004) Islands ofunburned habitat could provide partial refuge for sage-grouse occupying areas affected by wildfire (Steenvoordenet al 2019) which could prove to be important in areaswhere sage-grouse exhibit high degrees of site fidelityHowever it is unlikely that habitat in the form of islandscould fully compensate for potential population declinesfollowing fire Although further investigation is needed in-tact sagebrush islands appeared to be sparse within ourstudy area based on estimated loss of native plant commu-nities loss (Bureau of Land Management 2012) and typeconversion to cheatgrass approximately eight yearsfollowing the wildfire (Dudley 2020)Our findings are consistent with several studies show-

ing population impacts on sage-grouse following a majorwildfire event A simulation analysis conducted byPedersen et al (2003) found that under most scenariosfire resulted in reduced sage-grouse populations some-times leading to local population extirpation Resultsfrom Smith and Beck (2018) also demonstrated thatwildfire was associated with immediate and enduring ad-verse impacts on sage-grouse population change suchthat growth rates were reduced for up to 11 years postwildfire In the Great Basin sage-grouse populationswere predicted to decline 57 by 2044 if current annualgrassndashwildfire cycle trends continued (Coates et al2016) The results from our analysis are consistent withthose findings and provide a pattern-based case studythat demonstrates reductions in population size and sug-gests a potential mechanism for species range contrac-tion that can occur when peripheral populations areaffected (eg Coates et al 2019) Although not investi-gated as part of this study reductions in population sizefollowing wildfire are likely a function of reduced ratesof survival and recruitment (Foster et al 2019 Anthony2020 Dudley 2020) as well as potential emigration awayfrom affected areas Additional demographic studies areneeded to identify mechanisms by which wildfire influ-ences population dynamics and the long-term preva-lence of such negative effects

ConclusionsThis study contributes additional evidence that wildfirehas short-term negative impacts on sage-grouse popula-tions Long-term impacts are also likely given the timerequired for sagebrush communities to recover coupledwith the existing threat of permanent state transitions toannual grassland associated with a grassndashfire feedbackcycle (Balch et al 2013 Coates et al 2016 Shriver et al2019) Continued monitoring of wildfire-affected popula-tions is warranted as lingering wildfire effects may re-duce habitat quality and population capacity over anextended period (Coates et al 2016) In addition im-pacts to other sagebrush ecosystem species need

investigation to understand community-wide impacts onspecies diversity Active restoration efforts that facilitatesagebrush regrowth while providing short-term coverand resources for nesting and winter foraging (Pykeet al 2020 Ricca and Coates 2020) may be required tosustain local populations following increasingly frequentwildfire events affecting sage-grouse habitat across theextent of its range

AcknowledgementsWe thank R Croston K Miller and T Kimball for providing helpful commentsthat improved this manuscript This research was supported by funding fromthe California Department of Fish and Wildlife (CDFW) Bureau of LandManagement (BLM) and US Geological Survey (USGS) Collection of fielddata was supported by multiple federal and state agencies including CDFWBLM USGS Idaho State University and University of Idaho We areparticularly grateful to M Ricca (USGS) J Atkinson (USGS) R Kelble (USGS) JSeverson (USGS) S Mathews (USGS) A Johnson (BLM) K Miller (CDFW) andK Collum (BLM) for their contributions to field study logistics data andconceptual design We thank numerous technicians who helped conduct lekcounts Any use of trade firm or product names is for descriptive purposesonly and does not imply endorsement by the US Government

Authorsrsquo contributionsIn alphabetical order of last name PSC and DJD conceived idea anddesign IFD and SCG collected the data BGP IFD and STO analyzedthe data PSC DJD IFD SCG STO and BGP wrote and edited themanuscript PSC DJD and SCG contributed resources and funding Allauthors read and approved the final manuscript

FundingThis research was conducted under grants from California Department ofFish and Wildlife Bureau of Land Management and US Geological Survey

Availability of data and materialsThe data that support the findings of this study are available from CaliforniaDepartment of Fish and Wildlife but restrictions apply to the availability ofthese data which were used under license for the current study and so arenot publicly available Data are however available from the authors uponreasonable request and with permission of California Department of Fish andWildlife

Declarations

Ethics approval and consent to participateNot applicable

Consent for publicationNot applicable

Competing interestsThe authors declare that they have no competing interests

Author details1US Geological Survey Western Ecological Research Center Dixon FieldStation 800 Business Park Drive Suite D Dixon California 95620 USA2Department of Biological Sciences Idaho State University 921 South 8thAvenue Pocatello Idaho 83209 USA 3California Department of Fish andWildlife 1010 Riverside Parkway West Sacramento California 95605 USA

Received 28 July 2020 Accepted 9 March 2021

ReferencesAnthony CR 2020 Thermal ecology and population dynamics of female greater

sage-grouse following wildfire in the Trout Creek Mountains of Oregon andNevada Dissertation Corvallis USA Oregon State University

Armentrout DJ and F Hall 2005 Conservation strategy for sage-grouse(Centrocercus urophasianus) and sagebrush ecosystems within the Buffalo-

Dudley et al Fire Ecology (2021) 1715 Page 10 of 13

Skedaddle Population Management Unit Susanville Bureau of LandManagement Eagle Lake Field Office

Baker WL 2006 Fire and restoration of sagebrush ecosystems Wildlife SocietyBulletin 34 (1) 177ndash185 httpsdoiorg1021930091-7648(2006)34[177FAROSE]20CO2

Balch JK BA Bradley CM DrsquoAntonio and J Goacutemez-Dans 2013 Introducedannual grass increases regional fire activity across the arid western USA(1980-2009) Global Change Biology 19 (1) 173ndash183 httpsdoiorg101111gcb12046

Baruch-Mordo S JS Evans JP Severson DE Naugle JD Maestas JM Kiesecker MJ Falkowski CA Hagen and KP Reese 2013 Saving sage-grouse from the treesa proactive solution to reducing a key threat to a candidate species BiologicalConservation 167 233ndash241 httpsdoiorg101016jbiocon201308017

Battin J 2004 When good animals love bad habitats ecological traps and theconservation of animal populations Conservation Biology 18 (6) 1482ndash1491httpsdoiorg101111j1523-1739200400417x

Beck JL JW Connelly and KP Reese 2009 Recovery of greater sage-grousehabitat features in Wyoming big sagebrush following prescribed fire RestorationEcology 17 (3) 393ndash403 httpsdoiorg101111j1526-100X200800380x

Beck JL JW Connelly and CL Wambolt 2012 Consequences of treatingWyoming big sagebrush to enhance wildlife habitats Rangeland Ecology ampManagement 65 (5) 444ndash455 httpsdoiorg102111REM-D-10-001231

Blomberg E and C Hagen 2020 How many leks does it take Minimumsamples sizes for measuring local-scale conservation outcomes in greatersage-grouse Avian Conservation and Ecology 15 9 httpsdoiorg105751ACE-01517-150109

Blomberg EJ SR Poulson JS Sedinger and D Gibson 2013b Prefledging diet iscorrelated with individual growth in greater sage-grouse (Centrocercusurophasianus) The Auk 130 (4) 715ndash724 httpsdoiorg101525auk201312188

Blomberg EJ JS Sedinger DV Nonne and MT Atamian 2013a Annual malelek attendance influences count-based population indices of greater sage-grouse The Journal of Wildlife Management 77 (8) 1583ndash1592 httpsdoiorg101002jwmg615

Brooks ML CM DrsquoAntonio DM Richardson JB Grace JE Keeley JMDiTomaso RJ Hobbs M Pellant and D Pyke 2004 Effects of invasive alienplants on fire regimes BioScience 54 (7) 677ndash688 httpsdoiorg1016410006-3568(2004)054[0677EOIAPO]20CO2

Brooks ML JR Matchett DJ Shinneman and PS Coates 2015 Fire patterns inthe range of greater sage-grouse 1984-2013 implications for conservationand management In US Geological Survey Open-File Report 2015-1167 RestonUS Geological Survey httpsdoiorg103133ofr20151167

Bunting SC BM Kilgore and CL Bushey 1987 Guidelines for prescribedburning sagebrush-grass rangelands in the northern Great Basin In USDAGeneral Technical Report INT-GTR-231 Ogden USDA Forest ServiceIntermountain Research Station httpsdoiorg102737INT-GTR-231

Bureau of Land Management 2012 Environmental assessment Rush Fireemergency stabilization and rehabilitation DOI-BLM-CA-N050-2012-45-EASusanville Bureau of Land Management Eagle Lake Field Office

Carroll JM TJ Hovick CA Davis RD Elmore and SD Fuhlendorf 2017Reproductive plasticity and landscape heterogeneity benefit a ground-nesting bird in a fire-prone ecosystem Ecological Applications 27 (7) 2234ndash2244 httpsdoiorg101002eap1604

Chambers JC BA Bradley CS Brown C DrsquoAntonio MJ Germino JB Grace SPHardegree RF Miller and DA Pyke 2014 Resilience to stress anddisturbance and resistance to Bromus tectorum L invasion in cold desertshrublands of western North America Ecosystems 17 (2) 360ndash375 httpsdoiorg101007s10021-013-9725-5

Chambers JC BA Roundy RR Blank SE Meyer and A Whittaker 2007 Whatmakes Great Basin sagebrush ecosystems invasible by Bromus tectorumEcological Monographs 77 (1) 117ndash145 httpsdoiorg10189005-1991

Chevalier M JC Russell and J Knape 2019 New measures for evaluation ofenvironmental perturbations using Before-After-Control-Impact analysesEcological Applications 29 (2) e01838 httpsdoiorg101002eap1838

Coates PS and DJ Delehanty 2010 Nest predation of greater sage-grouse inrelation to microhabitat factors and predators Journal of WildlifeManagement 74 (2) 240ndash248 httpsdoiorg1021932009-047

Coates PS ST OrsquoNeil BE Brussee MA Ricca PJ Jackson JB Dinkins KBHowe AM Moser LJ Foster and DJ Delehanty 2020 Broad-scale impactsof an invasive native predator on a sensitive native prey species within theshifting avian community of the North American Great Basin BiologicalConservation 243 article108409 httpsdoiorg101016jbiocon2020108409

Coates PS BG Prochazka MA Ricca BJ Halstead ML Casazza EJ Blomberg BEBrussee L Wiechman J Tebbenkamp SC Gardner and KP Reese 2018 Therelative importance of intrinsic and extrinsic drivers to population growth varyamong local populations of greater sage-grouse an integrated populationmodeling approach Auk 135 (2) 240ndash261 httpsdoiorg101642AUK-17-1371

Coates PS MA Ricca BG Prochazka ML Brooks KE Doherty T Kroger EJBlomberg CA Hagen and ML Casazza 2016 Wildfire climate and invasivegrass interactions negatively impact an indicator species by reshapingsagebrush ecosystems Proceedings of the National Academy of Sciences 113(45) 12745ndash12750 httpsdoiorg101073pnas1606898113

Coates PS MA Ricca BG Prochazka ST OrsquoNeil JP Severson SR Mathews SEspinosa S Gardner S Lisius and DJ Delehanty 2019 Population andhabitat analyses for greater sage-grouse (Centrocercus urophasianus) in thebi-state distinct population segment 2018 update In US Geological SurveyOpen-File Report 2019-1149 Reston U S Geological Survey httpsdoiorg103133ofr20191149

Connelly JW CA Hagen and MA Schroeder 2011a Characteristics anddynamics of greater sage-grouse populations In Greater sage-grouse ecologyand conservation of a landscape species and its habitats ed ST Knick and JW Connelly 53ndash67 Berkeley University of California Press httpsdoiorg101525california97805202671140030004

Connelly JW ST Knick CE Braun WL Baker EA Beever TJ Christiansen KEDoherty EO Garton CA Hagen SE Hanser DH Johnson M Leu RF MillerDE Naugle SJ Oyler-McCance DA Pyke KP Reese MA Schroeder SJStiver BL Walker and MJ Wisdom 2011b Conservation of greater sage-grousemdasha synthesis of current trends and future management In Greatersage-grouse ecology and conservation of a landscape species and its habitatsed ST Knick and JW Connelly 549ndash563 Berkeley University of CaliforniaPress httpsdoiorg101525california97805202671140030025

Connelly JW KP Reese and MA Schroeder 2003 Monitoring of greater sage-grouse habitats and populations Station bulletin 80 Moscow Idaho Universityof Idaho College of Natural Resources Experiment Station httpsdoiorg105962bhltitle153828

Connelly JW and MA Schroeder 2007 Historical and current approaches tomonitoring greater sage-grouse In Proceedings of a symposium monitoringpopulations of sage-grouse Station bulletin 88 ed KP Reese and RT Bowyer3ndash9 Moscow Idaho University of Idaho College of Natural ResourcesExperiment Station

Connelly JW MA Schroeder AR Sands and CE Braun 2000 Guidelines tomanage sage grouse populations and their habitats Wildlife Society Bulletin28 967ndash985

Conner MM WC Saunders N Bouwes and C Jordan 2016 Evaluating impactsusing a BACI design ratios and a Bayesian approach with a focus onrestoration Environmental Monitoring and Assessment 188 (10) 555 httpsdoiorg101007s10661-016-5526-6

DrsquoAntonio CM and PM Vitousek 1992 Biological invasions by exotic grasses thegrassfire cycle and global change Annual Review of Ecology and Systematics 23(1) 63ndash87 httpsdoiorg101146annureves23110192000431

Davis DM and JA Crawford 2015 Case study short-term response of greatersage-grouse habitats to wildfire in mountain big sagebrush communitiesWildlife Society Bulletin 39 (1) 129ndash137 httpsdoiorg101002wsb505

Davis DM KP Reese and SC Gardner 2014 Diurnal space use and seasonalmovement patterns of greater sage-grouse in northeastern California WildlifeSociety Bulletin 38 (4) 710ndash720 httpsdoiorg101002wsb467

Doherty KE JS Evans PS Coates LM Juliusson and BC Fedy 2016Importance of regional variation in conservation planning a rangewideexample of the greater sage-grouse Ecosphere 7 (10) 1ndash27 httpsdoiorg101002ecs21462

Dudley IF 2020 Maladaptive nest site selection and reduced nest survival in femalesage-grouse following wildfire Thesis Pocatello USA Idaho State University

Eidenshink J B Schwind K Brewer ZL Zhu B Quayle and S Howard 2007 Aproject for monitoring trends in burn severity Fire Ecology 3 (1) 3ndash22 httpsdoiorg104996fireecology0301003

Fischer RA AD Apa WL Wakkinen KP Reese and JW Connelly 1993Nesting-area fidelity of sage grouse in southeastern Idaho Condor 95 (4)1038ndash1041 httpsdoiorg1023071369442

Foster LJ 2016 Resource selection and demographic rats of female sage-grousefollowing large-scale wildfire Thesis Corvallis USA Oregon State University

Foster LJ KM Dugger CA Hagen and DA Budeau 2019 Greater sage-grousevital rates after wildfire Journal of Wildlife Management 83 (1) 121ndash134httpsdoiorg101002jwmg21573

Dudley et al Fire Ecology (2021) 1715 Page 11 of 13

contribute to poor performance (Battin 2004) Islands ofunburned habitat could provide partial refuge for sage-grouse occupying areas affected by wildfire (Steenvoordenet al 2019) which could prove to be important in areaswhere sage-grouse exhibit high degrees of site fidelityHowever it is unlikely that habitat in the form of islandscould fully compensate for potential population declinesfollowing fire Although further investigation is needed in-tact sagebrush islands appeared to be sparse within ourstudy area based on estimated loss of native plant commu-nities loss (Bureau of Land Management 2012) and typeconversion to cheatgrass approximately eight yearsfollowing the wildfire (Dudley 2020)Our findings are consistent with several studies show-

ing population impacts on sage-grouse following a majorwildfire event A simulation analysis conducted byPedersen et al (2003) found that under most scenariosfire resulted in reduced sage-grouse populations some-times leading to local population extirpation Resultsfrom Smith and Beck (2018) also demonstrated thatwildfire was associated with immediate and enduring ad-verse impacts on sage-grouse population change suchthat growth rates were reduced for up to 11 years postwildfire In the Great Basin sage-grouse populationswere predicted to decline 57 by 2044 if current annualgrassndashwildfire cycle trends continued (Coates et al2016) The results from our analysis are consistent withthose findings and provide a pattern-based case studythat demonstrates reductions in population size and sug-gests a potential mechanism for species range contrac-tion that can occur when peripheral populations areaffected (eg Coates et al 2019) Although not investi-gated as part of this study reductions in population sizefollowing wildfire are likely a function of reduced ratesof survival and recruitment (Foster et al 2019 Anthony2020 Dudley 2020) as well as potential emigration awayfrom affected areas Additional demographic studies areneeded to identify mechanisms by which wildfire influ-ences population dynamics and the long-term preva-lence of such negative effects

ConclusionsThis study contributes additional evidence that wildfirehas short-term negative impacts on sage-grouse popula-tions Long-term impacts are also likely given the timerequired for sagebrush communities to recover coupledwith the existing threat of permanent state transitions toannual grassland associated with a grassndashfire feedbackcycle (Balch et al 2013 Coates et al 2016 Shriver et al2019) Continued monitoring of wildfire-affected popula-tions is warranted as lingering wildfire effects may re-duce habitat quality and population capacity over anextended period (Coates et al 2016) In addition im-pacts to other sagebrush ecosystem species need

investigation to understand community-wide impacts onspecies diversity Active restoration efforts that facilitatesagebrush regrowth while providing short-term coverand resources for nesting and winter foraging (Pykeet al 2020 Ricca and Coates 2020) may be required tosustain local populations following increasingly frequentwildfire events affecting sage-grouse habitat across theextent of its range

AcknowledgementsWe thank R Croston K Miller and T Kimball for providing helpful commentsthat improved this manuscript This research was supported by funding fromthe California Department of Fish and Wildlife (CDFW) Bureau of LandManagement (BLM) and US Geological Survey (USGS) Collection of fielddata was supported by multiple federal and state agencies including CDFWBLM USGS Idaho State University and University of Idaho We areparticularly grateful to M Ricca (USGS) J Atkinson (USGS) R Kelble (USGS) JSeverson (USGS) S Mathews (USGS) A Johnson (BLM) K Miller (CDFW) andK Collum (BLM) for their contributions to field study logistics data andconceptual design We thank numerous technicians who helped conduct lekcounts Any use of trade firm or product names is for descriptive purposesonly and does not imply endorsement by the US Government

Authorsrsquo contributionsIn alphabetical order of last name PSC and DJD conceived idea anddesign IFD and SCG collected the data BGP IFD and STO analyzedthe data PSC DJD IFD SCG STO and BGP wrote and edited themanuscript PSC DJD and SCG contributed resources and funding Allauthors read and approved the final manuscript

FundingThis research was conducted under grants from California Department ofFish and Wildlife Bureau of Land Management and US Geological Survey

Availability of data and materialsThe data that support the findings of this study are available from CaliforniaDepartment of Fish and Wildlife but restrictions apply to the availability ofthese data which were used under license for the current study and so arenot publicly available Data are however available from the authors uponreasonable request and with permission of California Department of Fish andWildlife

Declarations

Ethics approval and consent to participateNot applicable

Consent for publicationNot applicable

Competing interestsThe authors declare that they have no competing interests

Author details1US Geological Survey Western Ecological Research Center Dixon FieldStation 800 Business Park Drive Suite D Dixon California 95620 USA2Department of Biological Sciences Idaho State University 921 South 8thAvenue Pocatello Idaho 83209 USA 3California Department of Fish andWildlife 1010 Riverside Parkway West Sacramento California 95605 USA

Received 28 July 2020 Accepted 9 March 2021

ReferencesAnthony CR 2020 Thermal ecology and population dynamics of female greater

sage-grouse following wildfire in the Trout Creek Mountains of Oregon andNevada Dissertation Corvallis USA Oregon State University

Armentrout DJ and F Hall 2005 Conservation strategy for sage-grouse(Centrocercus urophasianus) and sagebrush ecosystems within the Buffalo-

Dudley et al Fire Ecology (2021) 1715 Page 10 of 13

Skedaddle Population Management Unit Susanville Bureau of LandManagement Eagle Lake Field Office

Baker WL 2006 Fire and restoration of sagebrush ecosystems Wildlife SocietyBulletin 34 (1) 177ndash185 httpsdoiorg1021930091-7648(2006)34[177FAROSE]20CO2

Balch JK BA Bradley CM DrsquoAntonio and J Goacutemez-Dans 2013 Introducedannual grass increases regional fire activity across the arid western USA(1980-2009) Global Change Biology 19 (1) 173ndash183 httpsdoiorg101111gcb12046

Baruch-Mordo S JS Evans JP Severson DE Naugle JD Maestas JM Kiesecker MJ Falkowski CA Hagen and KP Reese 2013 Saving sage-grouse from the treesa proactive solution to reducing a key threat to a candidate species BiologicalConservation 167 233ndash241 httpsdoiorg101016jbiocon201308017

Battin J 2004 When good animals love bad habitats ecological traps and theconservation of animal populations Conservation Biology 18 (6) 1482ndash1491httpsdoiorg101111j1523-1739200400417x

Beck JL JW Connelly and KP Reese 2009 Recovery of greater sage-grousehabitat features in Wyoming big sagebrush following prescribed fire RestorationEcology 17 (3) 393ndash403 httpsdoiorg101111j1526-100X200800380x

Beck JL JW Connelly and CL Wambolt 2012 Consequences of treatingWyoming big sagebrush to enhance wildlife habitats Rangeland Ecology ampManagement 65 (5) 444ndash455 httpsdoiorg102111REM-D-10-001231

Blomberg E and C Hagen 2020 How many leks does it take Minimumsamples sizes for measuring local-scale conservation outcomes in greatersage-grouse Avian Conservation and Ecology 15 9 httpsdoiorg105751ACE-01517-150109

Blomberg EJ SR Poulson JS Sedinger and D Gibson 2013b Prefledging diet iscorrelated with individual growth in greater sage-grouse (Centrocercusurophasianus) The Auk 130 (4) 715ndash724 httpsdoiorg101525auk201312188

Blomberg EJ JS Sedinger DV Nonne and MT Atamian 2013a Annual malelek attendance influences count-based population indices of greater sage-grouse The Journal of Wildlife Management 77 (8) 1583ndash1592 httpsdoiorg101002jwmg615

Brooks ML CM DrsquoAntonio DM Richardson JB Grace JE Keeley JMDiTomaso RJ Hobbs M Pellant and D Pyke 2004 Effects of invasive alienplants on fire regimes BioScience 54 (7) 677ndash688 httpsdoiorg1016410006-3568(2004)054[0677EOIAPO]20CO2

Brooks ML JR Matchett DJ Shinneman and PS Coates 2015 Fire patterns inthe range of greater sage-grouse 1984-2013 implications for conservationand management In US Geological Survey Open-File Report 2015-1167 RestonUS Geological Survey httpsdoiorg103133ofr20151167

Bunting SC BM Kilgore and CL Bushey 1987 Guidelines for prescribedburning sagebrush-grass rangelands in the northern Great Basin In USDAGeneral Technical Report INT-GTR-231 Ogden USDA Forest ServiceIntermountain Research Station httpsdoiorg102737INT-GTR-231

Bureau of Land Management 2012 Environmental assessment Rush Fireemergency stabilization and rehabilitation DOI-BLM-CA-N050-2012-45-EASusanville Bureau of Land Management Eagle Lake Field Office

Carroll JM TJ Hovick CA Davis RD Elmore and SD Fuhlendorf 2017Reproductive plasticity and landscape heterogeneity benefit a ground-nesting bird in a fire-prone ecosystem Ecological Applications 27 (7) 2234ndash2244 httpsdoiorg101002eap1604

Chambers JC BA Bradley CS Brown C DrsquoAntonio MJ Germino JB Grace SPHardegree RF Miller and DA Pyke 2014 Resilience to stress anddisturbance and resistance to Bromus tectorum L invasion in cold desertshrublands of western North America Ecosystems 17 (2) 360ndash375 httpsdoiorg101007s10021-013-9725-5

Chambers JC BA Roundy RR Blank SE Meyer and A Whittaker 2007 Whatmakes Great Basin sagebrush ecosystems invasible by Bromus tectorumEcological Monographs 77 (1) 117ndash145 httpsdoiorg10189005-1991

Chevalier M JC Russell and J Knape 2019 New measures for evaluation ofenvironmental perturbations using Before-After-Control-Impact analysesEcological Applications 29 (2) e01838 httpsdoiorg101002eap1838

Coates PS and DJ Delehanty 2010 Nest predation of greater sage-grouse inrelation to microhabitat factors and predators Journal of WildlifeManagement 74 (2) 240ndash248 httpsdoiorg1021932009-047

Coates PS ST OrsquoNeil BE Brussee MA Ricca PJ Jackson JB Dinkins KBHowe AM Moser LJ Foster and DJ Delehanty 2020 Broad-scale impactsof an invasive native predator on a sensitive native prey species within theshifting avian community of the North American Great Basin BiologicalConservation 243 article108409 httpsdoiorg101016jbiocon2020108409

Coates PS BG Prochazka MA Ricca BJ Halstead ML Casazza EJ Blomberg BEBrussee L Wiechman J Tebbenkamp SC Gardner and KP Reese 2018 Therelative importance of intrinsic and extrinsic drivers to population growth varyamong local populations of greater sage-grouse an integrated populationmodeling approach Auk 135 (2) 240ndash261 httpsdoiorg101642AUK-17-1371

Coates PS MA Ricca BG Prochazka ML Brooks KE Doherty T Kroger EJBlomberg CA Hagen and ML Casazza 2016 Wildfire climate and invasivegrass interactions negatively impact an indicator species by reshapingsagebrush ecosystems Proceedings of the National Academy of Sciences 113(45) 12745ndash12750 httpsdoiorg101073pnas1606898113

Coates PS MA Ricca BG Prochazka ST OrsquoNeil JP Severson SR Mathews SEspinosa S Gardner S Lisius and DJ Delehanty 2019 Population andhabitat analyses for greater sage-grouse (Centrocercus urophasianus) in thebi-state distinct population segment 2018 update In US Geological SurveyOpen-File Report 2019-1149 Reston U S Geological Survey httpsdoiorg103133ofr20191149

Connelly JW CA Hagen and MA Schroeder 2011a Characteristics anddynamics of greater sage-grouse populations In Greater sage-grouse ecologyand conservation of a landscape species and its habitats ed ST Knick and JW Connelly 53ndash67 Berkeley University of California Press httpsdoiorg101525california97805202671140030004

Connelly JW ST Knick CE Braun WL Baker EA Beever TJ Christiansen KEDoherty EO Garton CA Hagen SE Hanser DH Johnson M Leu RF MillerDE Naugle SJ Oyler-McCance DA Pyke KP Reese MA Schroeder SJStiver BL Walker and MJ Wisdom 2011b Conservation of greater sage-grousemdasha synthesis of current trends and future management In Greatersage-grouse ecology and conservation of a landscape species and its habitatsed ST Knick and JW Connelly 549ndash563 Berkeley University of CaliforniaPress httpsdoiorg101525california97805202671140030025

Connelly JW KP Reese and MA Schroeder 2003 Monitoring of greater sage-grouse habitats and populations Station bulletin 80 Moscow Idaho Universityof Idaho College of Natural Resources Experiment Station httpsdoiorg105962bhltitle153828

Connelly JW and MA Schroeder 2007 Historical and current approaches tomonitoring greater sage-grouse In Proceedings of a symposium monitoringpopulations of sage-grouse Station bulletin 88 ed KP Reese and RT Bowyer3ndash9 Moscow Idaho University of Idaho College of Natural ResourcesExperiment Station

Connelly JW MA Schroeder AR Sands and CE Braun 2000 Guidelines tomanage sage grouse populations and their habitats Wildlife Society Bulletin28 967ndash985

Conner MM WC Saunders N Bouwes and C Jordan 2016 Evaluating impactsusing a BACI design ratios and a Bayesian approach with a focus onrestoration Environmental Monitoring and Assessment 188 (10) 555 httpsdoiorg101007s10661-016-5526-6

DrsquoAntonio CM and PM Vitousek 1992 Biological invasions by exotic grasses thegrassfire cycle and global change Annual Review of Ecology and Systematics 23(1) 63ndash87 httpsdoiorg101146annureves23110192000431

Davis DM and JA Crawford 2015 Case study short-term response of greatersage-grouse habitats to wildfire in mountain big sagebrush communitiesWildlife Society Bulletin 39 (1) 129ndash137 httpsdoiorg101002wsb505

Davis DM KP Reese and SC Gardner 2014 Diurnal space use and seasonalmovement patterns of greater sage-grouse in northeastern California WildlifeSociety Bulletin 38 (4) 710ndash720 httpsdoiorg101002wsb467

Doherty KE JS Evans PS Coates LM Juliusson and BC Fedy 2016Importance of regional variation in conservation planning a rangewideexample of the greater sage-grouse Ecosphere 7 (10) 1ndash27 httpsdoiorg101002ecs21462

Dudley IF 2020 Maladaptive nest site selection and reduced nest survival in femalesage-grouse following wildfire Thesis Pocatello USA Idaho State University

Eidenshink J B Schwind K Brewer ZL Zhu B Quayle and S Howard 2007 Aproject for monitoring trends in burn severity Fire Ecology 3 (1) 3ndash22 httpsdoiorg104996fireecology0301003

Fischer RA AD Apa WL Wakkinen KP Reese and JW Connelly 1993Nesting-area fidelity of sage grouse in southeastern Idaho Condor 95 (4)1038ndash1041 httpsdoiorg1023071369442

Foster LJ 2016 Resource selection and demographic rats of female sage-grousefollowing large-scale wildfire Thesis Corvallis USA Oregon State University

Foster LJ KM Dugger CA Hagen and DA Budeau 2019 Greater sage-grousevital rates after wildfire Journal of Wildlife Management 83 (1) 121ndash134httpsdoiorg101002jwmg21573

Dudley et al Fire Ecology (2021) 1715 Page 11 of 13

Skedaddle Population Management Unit Susanville Bureau of LandManagement Eagle Lake Field Office

Baker WL 2006 Fire and restoration of sagebrush ecosystems Wildlife SocietyBulletin 34 (1) 177ndash185 httpsdoiorg1021930091-7648(2006)34[177FAROSE]20CO2

Balch JK BA Bradley CM DrsquoAntonio and J Goacutemez-Dans 2013 Introducedannual grass increases regional fire activity across the arid western USA(1980-2009) Global Change Biology 19 (1) 173ndash183 httpsdoiorg101111gcb12046

Baruch-Mordo S JS Evans JP Severson DE Naugle JD Maestas JM Kiesecker MJ Falkowski CA Hagen and KP Reese 2013 Saving sage-grouse from the treesa proactive solution to reducing a key threat to a candidate species BiologicalConservation 167 233ndash241 httpsdoiorg101016jbiocon201308017

Battin J 2004 When good animals love bad habitats ecological traps and theconservation of animal populations Conservation Biology 18 (6) 1482ndash1491httpsdoiorg101111j1523-1739200400417x

Beck JL JW Connelly and KP Reese 2009 Recovery of greater sage-grousehabitat features in Wyoming big sagebrush following prescribed fire RestorationEcology 17 (3) 393ndash403 httpsdoiorg101111j1526-100X200800380x

Beck JL JW Connelly and CL Wambolt 2012 Consequences of treatingWyoming big sagebrush to enhance wildlife habitats Rangeland Ecology ampManagement 65 (5) 444ndash455 httpsdoiorg102111REM-D-10-001231

Blomberg E and C Hagen 2020 How many leks does it take Minimumsamples sizes for measuring local-scale conservation outcomes in greatersage-grouse Avian Conservation and Ecology 15 9 httpsdoiorg105751ACE-01517-150109

Blomberg EJ SR Poulson JS Sedinger and D Gibson 2013b Prefledging diet iscorrelated with individual growth in greater sage-grouse (Centrocercusurophasianus) The Auk 130 (4) 715ndash724 httpsdoiorg101525auk201312188

Blomberg EJ JS Sedinger DV Nonne and MT Atamian 2013a Annual malelek attendance influences count-based population indices of greater sage-grouse The Journal of Wildlife Management 77 (8) 1583ndash1592 httpsdoiorg101002jwmg615

Brooks ML CM DrsquoAntonio DM Richardson JB Grace JE Keeley JMDiTomaso RJ Hobbs M Pellant and D Pyke 2004 Effects of invasive alienplants on fire regimes BioScience 54 (7) 677ndash688 httpsdoiorg1016410006-3568(2004)054[0677EOIAPO]20CO2

Brooks ML JR Matchett DJ Shinneman and PS Coates 2015 Fire patterns inthe range of greater sage-grouse 1984-2013 implications for conservationand management In US Geological Survey Open-File Report 2015-1167 RestonUS Geological Survey httpsdoiorg103133ofr20151167

Bunting SC BM Kilgore and CL Bushey 1987 Guidelines for prescribedburning sagebrush-grass rangelands in the northern Great Basin In USDAGeneral Technical Report INT-GTR-231 Ogden USDA Forest ServiceIntermountain Research Station httpsdoiorg102737INT-GTR-231

Bureau of Land Management 2012 Environmental assessment Rush Fireemergency stabilization and rehabilitation DOI-BLM-CA-N050-2012-45-EASusanville Bureau of Land Management Eagle Lake Field Office

Carroll JM TJ Hovick CA Davis RD Elmore and SD Fuhlendorf 2017Reproductive plasticity and landscape heterogeneity benefit a ground-nesting bird in a fire-prone ecosystem Ecological Applications 27 (7) 2234ndash2244 httpsdoiorg101002eap1604

Chambers JC BA Bradley CS Brown C DrsquoAntonio MJ Germino JB Grace SPHardegree RF Miller and DA Pyke 2014 Resilience to stress anddisturbance and resistance to Bromus tectorum L invasion in cold desertshrublands of western North America Ecosystems 17 (2) 360ndash375 httpsdoiorg101007s10021-013-9725-5

Chambers JC BA Roundy RR Blank SE Meyer and A Whittaker 2007 Whatmakes Great Basin sagebrush ecosystems invasible by Bromus tectorumEcological Monographs 77 (1) 117ndash145 httpsdoiorg10189005-1991

Chevalier M JC Russell and J Knape 2019 New measures for evaluation ofenvironmental perturbations using Before-After-Control-Impact analysesEcological Applications 29 (2) e01838 httpsdoiorg101002eap1838

Coates PS and DJ Delehanty 2010 Nest predation of greater sage-grouse inrelation to microhabitat factors and predators Journal of WildlifeManagement 74 (2) 240ndash248 httpsdoiorg1021932009-047

Coates PS ST OrsquoNeil BE Brussee MA Ricca PJ Jackson JB Dinkins KBHowe AM Moser LJ Foster and DJ Delehanty 2020 Broad-scale impactsof an invasive native predator on a sensitive native prey species within theshifting avian community of the North American Great Basin BiologicalConservation 243 article108409 httpsdoiorg101016jbiocon2020108409

Coates PS BG Prochazka MA Ricca BJ Halstead ML Casazza EJ Blomberg BEBrussee L Wiechman J Tebbenkamp SC Gardner and KP Reese 2018 Therelative importance of intrinsic and extrinsic drivers to population growth varyamong local populations of greater sage-grouse an integrated populationmodeling approach Auk 135 (2) 240ndash261 httpsdoiorg101642AUK-17-1371

Coates PS MA Ricca BG Prochazka ML Brooks KE Doherty T Kroger EJBlomberg CA Hagen and ML Casazza 2016 Wildfire climate and invasivegrass interactions negatively impact an indicator species by reshapingsagebrush ecosystems Proceedings of the National Academy of Sciences 113(45) 12745ndash12750 httpsdoiorg101073pnas1606898113

Coates PS MA Ricca BG Prochazka ST OrsquoNeil JP Severson SR Mathews SEspinosa S Gardner S Lisius and DJ Delehanty 2019 Population andhabitat analyses for greater sage-grouse (Centrocercus urophasianus) in thebi-state distinct population segment 2018 update In US Geological SurveyOpen-File Report 2019-1149 Reston U S Geological Survey httpsdoiorg103133ofr20191149

Connelly JW CA Hagen and MA Schroeder 2011a Characteristics anddynamics of greater sage-grouse populations In Greater sage-grouse ecologyand conservation of a landscape species and its habitats ed ST Knick and JW Connelly 53ndash67 Berkeley University of California Press httpsdoiorg101525california97805202671140030004

Connelly JW ST Knick CE Braun WL Baker EA Beever TJ Christiansen KEDoherty EO Garton CA Hagen SE Hanser DH Johnson M Leu RF MillerDE Naugle SJ Oyler-McCance DA Pyke KP Reese MA Schroeder SJStiver BL Walker and MJ Wisdom 2011b Conservation of greater sage-grousemdasha synthesis of current trends and future management In Greatersage-grouse ecology and conservation of a landscape species and its habitatsed ST Knick and JW Connelly 549ndash563 Berkeley University of CaliforniaPress httpsdoiorg101525california97805202671140030025

Connelly JW KP Reese and MA Schroeder 2003 Monitoring of greater sage-grouse habitats and populations Station bulletin 80 Moscow Idaho Universityof Idaho College of Natural Resources Experiment Station httpsdoiorg105962bhltitle153828

Connelly JW and MA Schroeder 2007 Historical and current approaches tomonitoring greater sage-grouse In Proceedings of a symposium monitoringpopulations of sage-grouse Station bulletin 88 ed KP Reese and RT Bowyer3ndash9 Moscow Idaho University of Idaho College of Natural ResourcesExperiment Station

Connelly JW MA Schroeder AR Sands and CE Braun 2000 Guidelines tomanage sage grouse populations and their habitats Wildlife Society Bulletin28 967ndash985

Conner MM WC Saunders N Bouwes and C Jordan 2016 Evaluating impactsusing a BACI design ratios and a Bayesian approach with a focus onrestoration Environmental Monitoring and Assessment 188 (10) 555 httpsdoiorg101007s10661-016-5526-6

DrsquoAntonio CM and PM Vitousek 1992 Biological invasions by exotic grasses thegrassfire cycle and global change Annual Review of Ecology and Systematics 23(1) 63ndash87 httpsdoiorg101146annureves23110192000431

Davis DM and JA Crawford 2015 Case study short-term response of greatersage-grouse habitats to wildfire in mountain big sagebrush communitiesWildlife Society Bulletin 39 (1) 129ndash137 httpsdoiorg101002wsb505

Davis DM KP Reese and SC Gardner 2014 Diurnal space use and seasonalmovement patterns of greater sage-grouse in northeastern California WildlifeSociety Bulletin 38 (4) 710ndash720 httpsdoiorg101002wsb467

Doherty KE JS Evans PS Coates LM Juliusson and BC Fedy 2016Importance of regional variation in conservation planning a rangewideexample of the greater sage-grouse Ecosphere 7 (10) 1ndash27 httpsdoiorg101002ecs21462

Dudley IF 2020 Maladaptive nest site selection and reduced nest survival in femalesage-grouse following wildfire Thesis Pocatello USA Idaho State University

Eidenshink J B Schwind K Brewer ZL Zhu B Quayle and S Howard 2007 Aproject for monitoring trends in burn severity Fire Ecology 3 (1) 3ndash22 httpsdoiorg104996fireecology0301003

Fischer RA AD Apa WL Wakkinen KP Reese and JW Connelly 1993Nesting-area fidelity of sage grouse in southeastern Idaho Condor 95 (4)1038ndash1041 httpsdoiorg1023071369442

Foster LJ 2016 Resource selection and demographic rats of female sage-grousefollowing large-scale wildfire Thesis Corvallis USA Oregon State University

Foster LJ KM Dugger CA Hagen and DA Budeau 2019 Greater sage-grousevital rates after wildfire Journal of Wildlife Management 83 (1) 121ndash134httpsdoiorg101002jwmg21573

Dudley et al Fire Ecology (2021) 1715 Page 11 of 13

Garton EO AG Wells JA Baumgardt and JW Connelly 2015 Greater sage-grouse population dynamics and probability of persistence Final report to PewCharitable Trusts Philadelphia Pew Charitable Trusts httpswwweenewsnetassets20150424document_daily_03pdf

Gibson D EJ Blomberg MT Atamian and JS Sedinger 2017 Weather habitatcomposition and female behavior interact to modify offspring survival in greatersage grouse Ecological Applications 27 (1) 168ndash181 httpsdoiorg101002eap1427

Green AW CL Aldridge and MS OrsquoDonnell 2017 Investigating impacts of oiland gas development on greater sage-grouse Journal of WildlifeManagement 81 (1) 46ndash57 httpsdoiorg101002jwmg21179

Green RH 1979 Sampling design and statistical methods for environmentalbiologists New York Wiley

Hess JE and JL Beck 2012 Burning and mowing Wyoming big sagebrush dotreated sites meet minimum guidelines for greater sage-grouse breedinghabitats Wildlife Society Bulletin 36 (1) 85ndash93 httpsdoiorg101002wsb92

Hobbs RJ S Arico J Aronson JS Baron P Bridgewater VA Cramer PREpstein JJ Ewel CA Klink and AE Lugo 2006 Novel ecosystemstheoretical and management aspects of the new ecological world orderGlobal Ecology and Biogeography 15 (1) 1ndash7 httpsdoiorg101111j1466-822X200600212x

Howe KB PS Coates and DJ Delehanty 2014 Selection of anthropogenicfeatures and vegetation characteristics by nesting common ravens in thesagebrush ecosystem Condor 116 (1) 35ndash49 httpsdoiorg101650CONDOR-13-115-R21

Johnson DH and MM Rowland 2007 The utility of lek counts for monitoringgreater sage-grouse In Proceedings of a symposium monitoring populations ofsage-grouse Station bulletin 88 ed KP Reese and RT Bowyer 15ndash23 MoscowIdaho University of Idaho College of Natural Resources Experiment Station

Keacutery M and M Schaub 2011 Bayesian population analysis using WinBUGS ahierarchical perspective Burlington Academic

Knapp PA 1996 Cheatgrass (Bromus tectorum L) dominance in the Great Basindesert history persistence and influences to human activities GlobalEnvironmental Change 6 (1) 37ndash52 httpsdoiorg1010160959-3780(95)00112-3

Knick ST and SE Hanser 2011 Connecting pattern and process in greater sage-grouse populations and sagebrush landscapes In Greater sage-grouseecology and conservation of a landscape species and its habitats Studies inAvian Biology Volume 38 ed ST Knick and JW Connelly 383ndash405 BerkeleyUniversity of California Press httpsdoiorg101525california97805202671140030017

Knick ST SE Hanser and KL Preston 2013 Modeling ecological minimumrequirements for distribution of greater sage-grouse leks implications forpopulation connectivity across their western range USA Ecology andEvolution 3 (6) 1539ndash1551 httpsdoiorg101002ece3557

Lee PM 1997 Bayesian statistics an introduction 3rd ed London Arnold HodderEducation Publishers

Lockyer ZB PS Coates ML Casazza S Espinosa and DJ Delehanty 2015 Nest-site selection and reproductive success of greater sage-grouse in a fire-affected habitat of northwestern Nevada Journal of Wildlife Management 79(5) 785ndash797 httpsdoiorg101002jwmg899

Miller RF JC Chambers DA Pyke FB Pierson and CJ Williams 2013 A reviewof fire effects on vegetation and soils in the Great Basin region response andecological site characteristics In USDA Forest Service General Technical ReportRMRS GTR-308 Fort Collins USDA Forest Service Rocky Mountain ResearchStation httpsdoiorg102737RMRS-GTR-308

Miller RF ST Knick DA Pyke CW Meinke SE Hanser MJ Wisdom and ALHild 2011 Characteristics of sagebrush habitats and limitations to long-termconservation In Greater sage-grouse ecology and conservation of a landscapespecies and its habitats Studies in avian biology volume 38 ed ST Knick andJW Connelly 145ndash184 Berkeley University of California Press httpsdoiorg101525california97805202671140030011

Monroe AP CL Aldridge TJ Assal KE Veblen DA Pyke and ML Casazza2017 Patterns in greater sage-grouse population dynamics correspond withpublic grazing records at broad scales Ecological Applications 27 (4) 1096ndash1107 httpsdoiorg101002eap1512

Monroe AP DR Edmunds and CL Aldridge 2016 Effects of lek countprotocols on greater sage-grouse population trend estimates Journal ofWildlife Management 80 (4) 667ndash678 httpsdoiorg101002jwmg1050

Nelle PJ KP Reese and JW Connelly 2000 Long-term effects of fire on sagegrouse habitat Journal of Range Management 53 (6) 586ndash591 httpsdoiorg1023074003151

OrsquoNeil ST PS Coates BE Brussee PJ Jackson KB Howe AM Moser LJ Fosterand DJ Delehanty 2018 Broad-scale occurrence of a subsidized avian predatorReducing impacts of ravens on sage-grouse and other sensitive prey Journal ofApplied Ecology 55 (6) 2641ndash2652 httpsdoiorg1011111365-266413249

ONeil ST PS Coates BE Brussee MA Ricca SP Espinosa S Gardner and DJDelehanty 2020 Wildfire and the ecological niche diminishing habitatsuitability for an indicator species within semi-arid ecosystems GlobalChange Biology 26 (11) 6296ndash6312 httpsdoiorg101111gcb15300

Patterson RL 1952 The sage grouse in Wyoming Denver Sage BooksPechony O and DT Shindell 2010 Driving forces of global wildfires over the

past millennium and the forthcoming century Proceedings of the NationalAcademy of Sciences 107 (45) 19167ndash19170 httpsdoiorg101073pnas1003669107

Pedersen EK JW Connelly JR Hendrickson and WE Grant 2003 Effect of sheepgrazing and fire on sage grouse populations in southeastern Idaho EcologicalModelling 165 (1) 23ndash47 httpsdoiorg101016S0304-3800(02)00382-4

Pilliod DS JL Welty and RS Arkle 2017 Refining the cheatgrass-fire cycle inthe Great Basin precipitation timing and fine fuel composition predictwildfire trends Ecology and Evolution 7 (19) 8126ndash8151 httpsdoiorg101002ece33414

Plummer M 2017 JAGS Version 430 user manual Lyon International Agency forResearch on Cancer

Plummer M 2019 rjags Bayesian graphical models using MCMC R packageversion 4-10 httpsCRANR-projectorgpackage=rjags Accessed 2 Mar 2021

Pyke DA RK Shriver RS Arkle DS Pilliod CL Aldridge PS Coates MJGermino JA Heinrichs MA Ricca and SE Shaff 2020 Postfire growth ofseeded and planted big sagebrushmdashstrategic designs for restoring greatersage-grouse nesting habitat Restoration Ecology 28 (6) 1495ndash1504 httpsdoiorg101111rec13264

Queen JP GP Quinn and MJ Keough 2002 Experimental design and dataanalysis for biologists Cambridge Cambridge University Press httpsdoiorg101017CBO9780511806384

R Core Team 2017 R A language and environment for statistical computingVienna R Foundation for Statistical Computing httpswwwR-projectorg

Remeš VR 2000 How can maladaptive habitat choice generate source-sinkpopulation dynamics Oikos 91 (3) 579ndash582 httpsdoiorg101034j1600-07062000910320x

Rhodes EC JD Bates RN Sharp and KW Davies 2010 Fire effects on coverand dietary resources of sage-grouse habitat Journal of Wildlife Management74 (4) 755ndash764 httpsdoiorg1021932009-143

Ricca MA and PS Coates 2020 Integrating ecosystem resilience and resistanceinto decision support tools for multi-scale population management of asagebrush indicator species Frontiers in Ecology and Evolution 7 493 httpsdoiorg103389fevo201900493

Robertson BA JS Rehage and A Sih 2013 Ecological novelty and theemergence of evolutionary traps Trends in Ecology amp Evolution 28 (9) 552ndash560 httpsdoiorg101016jtree201304004

Row JR KE Doherty TB Cross MK Schwartz SJ Oyler-McCance DE NaugleST Knick and BC Fedy 2018 Quantifying functional connectivity the roleof breeding habitat abundance and landscape features on range-wide geneflow in sage-grouse Evolutionary Applications 11 (8) 1305ndash1321 httpsdoiorg101111eva12627

Row JR and BC Fedy 2017 Spatial and temporal variation in the range-widecyclic dynamics of greater sage-grouse Oecologia 185 (4) 687ndash698 httpsdoiorg101007s00442-017-3970-9

Royle JA and RM Dorazio eds 2008 Hierarchical modeling and inference in ecologythe analysis of data from populations metapopulations and communitiesAmsterdam Elsevier httpsdoiorg101016B978-0-12-374097-750001-5

Schroeder MA and LA Robb 2003 Fidelity of greater sage-grouse Centrocercusurophasianus to breeding areas in a fragmented landscape Wildlife Biology 9(1) 291ndash299 httpsdoiorg102981wlb2003017

Shriver RK CM Andrews RS Arkle DM Barnard MC Duniway MJ Germino DSPilliod DA Pyke JL Welty and JB Bradford 2019 Transient populationdynamics impede restoration and may promote ecosystem transformation afterdisturbance Ecology Letters 22 (9) 1357ndash1366 httpsdoiorg101111ele13291

Shultz LM 2006 Artemisia L In Flora of North America north of Mexico ed theFlora of North America editorial committee 503ndash534 New York OxfordUniversity Press

Smith KT and JL Beck 2018 Sagebrush treatments influence annualpopulation change for greater sage-grouse Restoration Ecology 26 (3) 497ndash505 httpsdoiorg101111rec12589

Dudley et al Fire Ecology (2021) 1715 Page 12 of 13

Steenvoorden J AJ Meddens AJ Martinez LJ Foster and WD Kissling 2019The potential importance of unburned islands as refugia for the persistenceof wildlife species in fire-prone ecosystems Ecology and Evolution 9 (15)8800ndash8812 httpsdoiorg101002ece35432

Stewart-Oaten A WW Murdoch and KR Parker 1986 Environmental impactassessment ldquopseudoreplicationrdquo in time Ecology 67 (4) 929ndash940 httpsdoiorg1023071939815

Underwood AJ 1992 Beyond BACI the detection of environmental impacts onpopulations in the real but variable world Journal of Experimental MarineBiology and Ecology 161 (2) 145ndash178 httpsdoiorg1010160022-0981(92)90094-Q

US Fish and Wildlife Service 2015 Endangered and threatened wildlife andplants 12-month finding on a petition to list greater sage-grouse(Centrocercus urophasianus) as an endangered or threatened speciesproposed rule Federal Register 80 59857ndash59942

WAFWA [Western Association of Fish and Wildlife Agencies] 2015 Greater sage-grouse population trends an analysis of lek count databases 1965-2015Cheyenne Western Association of Fish and Wildlife Agencies httpwwwwafwaorgDocuments and Settings37Site DocumentsNewsLek Trend Analysis final 8-14-15pdf Accessed 20 Aug 2015

Wann GT PS Coates BG Prochazka JP Severson AP Monroe and CLAldridge 2019 Assessing lek attendance of male greater sage-grouse usingfine-resolution GPS data implications for population monitoring of lekmating grouse Population Ecology 61 (2) 183ndash197 httpsdoiorg1010021438-390X1019

Young JA 1992 Ecology and management of medusahead (Taeniatherumcaput-medusae spp) Great Basin Naturalist 52 245ndash252 httpsscholarsarchivebyuedugbnvol52iss36

Publisherrsquos NoteSpringer Nature remains neutral with regard to jurisdictional claims inpublished maps and institutional affiliations

Dudley et al Fire Ecology (2021) 1715 Page 13 of 13