birds and climate report

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Birds and Climate Change

Ecological Disruption in Motion

A Brieng or Policymakers and Concerned Citizenson Audubons Analyses o North AmericanBird Movements in the Face o Global Warming

February, 2009


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Birds and Climate Change Ecological Disruption in Motion

Science reveals the message rom the birds

Each year or more than a century, dedicated volunteers have braved snow,wind, rain and ice to record the number and location o North Americanbirds. The careully organized and compiled observations o tens othousands o Citizen Scientists participating in Audubons annual ChristmasBird Count have grown to orm the worlds longest uninterrupted

repository o bird population inormation. Analyses o its data have timeater time revealed important trends, alerting America to perils andopportunities with implications ar beyond avian well-being. Birds are well-known barometers o environmental health. Changes in their condition canwarn o threats to habitats and natural systems critical to all lie on earth.Like canaries in a coal mine, they can alert us to danger. And, i we heedtheir warnings, caring or the birds can help us protect ourselves and theuture o the world we share.

Amid mounting concerns over accelerating global climate change, Audubonlooked to the birds to determine i and how these sensitive creaturesmight be responding to changes here in the continental U.S. Birders havelong reported surprising sightings o species ar north o expected ranges.But are the reports signicant? I so, are they connected to documentedchanges in our climate? Analyses o our decades o Christmas Bird Countdata provide some answers. The results conrm what bird lovers have long

suspected. Findings summarized in the pages that ollow oer a look atorty years o change, a peek at what the uture likely holds in one part oour nation, and an urgent message o warning rom the birdsa messagewe would be wise to heed.

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It took legions of bird-loving citizen scientists to document how North

Americas birds are responding in the face of global warming. It will

take action by Americas millions of self-proclaimed bird enthusiasts

and their elected representativesto address the problem of climate

change while theres still time.

Front cover: Greater Yellowlegs by Donna Dewhurst / USFWS.The Greater Yellowlegs has shited its wintering range 124 miles north in the last 40 years.


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A Brieng or Policymakers and Concerned Citizens | February 2009

Birds on the Move ShowSignicant Changes Underway

Analysis o our decades o Christmas Bird Count observations reveal that birds seen

in North America during the rst weeks o winter have moved dramatically northwardtoward colder latitudesover the past our decades. Signicant northward movementoccurred among 58% o the observed species177 o 305. More than 60 moved in

excess o 100 miles north, while the average distance moved by all studied speciesincluding those that did not refect the trendwas 35 miles northward.

There was also movement inland, rom warmer coastal states into areas not longaccustomed to winter temperatures suitable or their new arrivals.

The analysis ound these trends among nearly every type o species; their sheernumbers and variety pointing to a powerul common orce contributing to the movements.

Audubons Christmas Bird Count tallies the species and number o birds in 2,000 specied locations (count

circles) each year within two weeks o Christmas. Audubon scientists analyzed orty years o CBC data(Christmas 1966-2005), examining observations on 305 species that are regularly encountered in ve or more

states or provinces to assess changes in the range o North American birds. Identied range changes are basedupon movement in the centers o abundance or each o the 305 species hal the individuals o a species areound south o the center o abundance; the other hal are ound north.

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All species Landbirds Waterbirds Coastal species

Northward shit in center o abundance over 40 years

Figure 1, Source: National Audubon Society

Miles


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The Climate CulpritClimbing average annual temperatures have been well documented by scientists studying

global warming. Average temperatures or January, the coldest month, rose more than vedegrees F. in the continental U.S. over the past 40 years (gure 2).

Temperature increases coincided with anecdotal reports o northward movement obird populationsnow conrmed by Audubons analysis (Figure 3).

Is climate change causing bird movements? While causation is nearly impossibleto prove, global climate change is by ar the most probable explanation. Indeed, themovements are consistent with birds biological needs.

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Average January temperature across the lower 48 states

Figure 2, Source: National Oceanic and Atmospheric Administration

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Let to right: The Brant (a coastal bird), Ring-necked Duck (a waterbird), and American Goldnch (a landbird), all moved about 200 miles north over

our decades.

LeeKarney/USFWS

AshokKhosla


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Birds requently alter their ranges d

to many actors, especially habitatchanges and interactions with othe

species. Audubon does not sug-gest that all the birds that movednorth or inland did so in response

to climate change; a wide variety oother actors play a contributing ro

and explain why a minority o specishowed no movement or even shit

southward. However, the correla-tion between shiting ranges andwinter temperature trends cannot

be ignored in explaining some o thewidespread and directionally con-

sistent movements seen among U.Sbird species. Among key ndings:

1Annual latitudinal distributions obirds are correlated with annualtemperatures.

2Among states and provinces, rato bird population change arecorrelated with rates o temperatu

change, independent o latitude.

3Among all the species in ourstudy, twice as many bird spe-cies moved north as south; twice amany species moved inland as movecoastally. Both o these directional

movements are consistent with aclimate change model. However, an

equal number o birds moved east amoved west. Under global warming

movements away rom the Atlanticand Pacic should be about equal,with no other expectation o dier-

ences in east-west movement.

4Latitudinal movement patternsamong birds centered in dierenlatitudinal regions o North Americ

are generally consistent with a climchange model, but inconsistent with

movements predicted as a result orange shits in response to populati

increases or decreases.

5Birds ound only in a ew southestates, and thus not included inthe main part o this study, have be

observed in increasing numbers, sugesting that they have moved north

rom south o the United States.

Change in center o abundance among305 widespread bird species in North America

Figure 3, Source: National Audubon Society

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|Were seeing compelling signs that climate change has been with

us and having serious biological consequences for the past 40years. Little else could explain this kind of spectacular movement

across such a wide range of birds.

Rising winter temperatures make northern latitudes increasingly morehospitable to many species commonly ound arther south. Audubonsanalysis reveals that species populations grew the most in the statesexperiencing the greatest warming, surpassing the growth in areas that didnot warm as much. Similarly, the warming climates moderation o inlandtemperature extremes allows species to shit inland rom the coast.

Citizen scientists have long observed that conditions in late all and

early winter predict how ar north many species will be ound during theChristmas Bird Count that ollows soon ater. Audubons analysis conrmstheir suspicions, revealing statistical correlation between annual specieslocations and the November/December temperature fuctuations leading upto the count. In combination, these ndings leave little doubt that ongoingclimate change is a primary and direct actor in the overall shit o manywinter ranges.


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On the MoveOver the past 40 years, the Christmas Bird Count has documented shits to the north

or inland or the majority and or nearly every kind o North American bird species.Audubons analysis conrms the anecdotal evidence rom bird enthusiasts who haverequently reported changing populations lling their skies.

Given the strong evidence that global warming is indeed a key actor in observed birdmovements, shits like these will continue or amiliar speciesor better or worseaslong as the climate continues to change. Though these movements clearly point tosignicant ecological disruption underway, their short and long term impacts will vary orspecic species and even groups.

Red-breasted MerganserMoved 317 miles North

American Black DuckMoved 182 miles North

Green-winged TealMoved 157 miles North

DaveMenke/USFWS

SteveMaslowski/USFWS

DonnaDewhurst/USFWS

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We must act decisively to control global warming pollution to curb the worst impacts

of climate change, and take immediate steps to help birds and other species weatherthe changes we cannot avoid.


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To an Uncertain FatewaterBirds

More than hal o the waterbird species (52%) moved north, including a wide variety oducks, such as Red-breasted Merganser, American Black Duck, and Green-winged Teal.Waterbirds have beneted in recent years rom less ice cover in northern and interior

states, but uture conditions under global warming scenarios are not promisinga hotterand drier climate will dry many wetlands that waterbirds require.

Coastal BirdsCoastal waterbirds did not move inland, primarily because they require saltwater or

habitats ound only near saltwater. However, many o these species (46%) still movednorth, including the Black-bellied Plover and Black Turnstone (shorebirds), and NorthernGannet (a large sh-eating bird). The short-term health o many o these species is alreadyin decline rom development and the degradation o coastal habitats. These areas need

signicant protection and restoration. In addition, avian dietsnot to mention seaoodproductionare threatened by the loss o ood-rich ocean currents that disappear or

become less predictable with global warming. Coastal habitats themselves are urtherthreatened by sea-level rise associated with climate change.

ack-bellied Ploverved Moved 114 miles north

Black TurnstoneMoved 178 miles North

Northern GannetMoved 83 miles North

TimBowman/USFWS

RyanHagerty/USFWS


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landBirdsAmong all landbirds in the study, 64% showed signicant northward movement,

including more than 70% o all woodland birds and 70% o those that requent eeders.

Feeder birdssuch as Pine Siskin, Boreal Chickadee, and Pygmy Nuthatch have movedhundreds o miles since 1966. Already adapted to human habitats, they are unusuallywell suited to a shiting climate. Most will are well in the short term, as long as ood isprovided. However, northern-wintering birds are highly vulnerable to the sudden onset o

cold and stormy conditions. They are also likely to urther disrupt ecosystem balance bydisplacing less adaptable species.

Woodland birdsthat do not visit bird eeders, such as Spruce Grouse, AmericanThree-toed Woodpecker, and Barred Owl, also showed long-distance northwardmovements. Their continued success in northern winters will depend on healthy oresthabitat, which is already at risk due to both the drying eects o global warming and over-exploitation by humans.

Grassland birdsincluding Eastern Meadowlark, Vesper Sparrow, and Burrowing Owlare among the ew groups that did not move north over the past 40 years. Only 10 o 26(38%) grassland species moved north signicantly, while nine moved south. Most probably

could not move into northern areas despite increasingly moderate temperatures becauseconversion to intensive human uses such as row crops, pastures, and hayelds has greatlyreduced availability o grassland habitat. In combination, global warming and ongoingoveruse o grasslands by humans will doom grassland birds to continued populationdeclines i we ail to take corrective actions.

Pine SiskinMoved 288 miles North

Spruce GrouseMoved 316 miles North

Western MeadowlarkMoved 25 miles South

GlennTepke

GlennTepke

John&KarenHollingsworth

/USFWS


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Threats to Species,Habitats and More

Whether they have already shited their ranges or are unable to do so, bird speciesillustrate how the impact o global warming compounds other well-known threats.

Scientists have long predicted dire consequences rom global warming or birds and otherspecies.

International experts rom the Nobel Prize-winning Intergovernmental Panel on

Climate Change warned in 2007 that approximately 20-30% o plant and animal speciesassessed so ar are likely to be at increased risk o extinction i increases in global averagetemperatures exceed 1.5-2.5 degrees C. Others have projected that more than 30% oNeotropical songbirds could be lost in some parts o the continental U.S.

While these predictions are outside the scope o Audubons analysis, the study revealsthat the ecological disruptions that threaten birds, other wildlie and human communitiesare likely already in motion. Arctic and alpine tundra and coastal beaches, salt marshes,

and mangroves are in great jeopardy. As the world warms, permarost underlying thetundra will melt, allowing the habitat to be invaded by woody plants. As sea level rises,all coastal habitats are at risk. In undeveloped areas, coastal habitats may recede inland;but in developed areas, people and natural habitats will compete or the decreasing space.Habitats such as grasslands and deserts (including signicant parts o the American West)will ace increasing stresses, as will the species that depend on them. Careully planned,science-based habitat conservation eorts will be increasingly essential to avoid a growingtoll on birds and wildlie, along with the loss o a wide array o ecological benets, romclean water supplies, and the insect control and seed distribution provided by birds, totravel and tourism revenues. According to the U.S. Fish and Wildlie Service, birding

related activities alone generate $85 billion in input to Americas economy.

USFWS


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Moving Toward the FutureThe need to address the impact o climate change on bird populations is also

demonstrated by additional new research conducted by Audubon Caliornia. The newanalysis models changes in geographic ranges over the next 100 years and indicatesthat about 80 o Caliornias 310 native bird species will lose at least a quarter o their

distributions in the next several decades due to climate change. These reductions will bepart o massive range shits among all o the states bird species caused wholly or in part

by the eects o climate change.Models used in this research indicate that the magnitude o bird range loss in Caliornia

will depend in large part on the steps we take now to reduce greenhouse gas emissionsworldwide.

Scenarios generated by the Intergovernmental Panel on Climate Changeinorm the Caliornia research by dening emission levels

or low, medium and high scenarios.

Figure 4, Source: Graphic adapted rom IPCC 2007 by National Audubon Society

Low Medium High

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As emissions increase, the research projects a growing impact on birds, as illustrated byve amiliar Caliornia species.

|Audubon California models identify where conservation investmentsare likely to have the biggest impact. We must combine efforts to curb

global warming emissions with science-based habitat conservation

planning and execution if we hope to maintain healthy habitat for

birds, other wildlife and people.

Photos (L to R): Ashok Khosla, Dennis Ancinec, Bob Martinka, Glenn Tepke, Lee Karney / USFWS

Figure 5, Source: Audubon Caliornia

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Chestnut-backedChickadee

Gray-cownedRosy-Finch

GrasshopperSparrow

CaliorniaGnatcatcher

Yellow-billedMagpie

Range Loss under three emission scenarios.


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The Outlook or One SpeciesProjected range changes or the Caliornia Gnatcatcher over the next hundred years

illustrate the impact o climate change, while identiying areas where uture conservationcan shape its long-term prognosis. This projection is based on the medium-level emissionsscenario.

The ndings were derived by combining 40 years o data compiled by volunteers or the Audubon ChristmasBird Count with Breeding Bird Survey inormation and geographic climate data. Datasets were used to build a

Geographic Inormation Systems library and database, allowing researchers to identiy and map habitat areaswhere species o special concern will benet rom habitat conservation. A critical element o these models isthe inclusion o climate change data layers summarized by the Intergovernmental Panel on Climate Change.

Figure 6, Source: Audubon Caliornia


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Global Warming RequiresImmediate Action

Whether seen in the movement o the birds, or the melting o ice caps, the evidencecannot be deniedecological disruption is underway. Failure to prevent the worst impacts

o global warming would undermine much o the conservation work that Audubon hasaccomplished over more than a century. Tackling this critically important challenge is oneo Audubons top priorities. Species at greatest risk may already be unable to escape the

worst consequences o climate change. But there is still opportunity to protect most birds,wildlie, and habitat rom the growing threats posed by accelerating global warming. To doso, we must reduce global warming pollution to the levels recommended by the worldsleading scientists.

Scientists agree that immediate and ar-reaching action is needed to prevent globalaverage temperatures rom increasing more than another 2 F. rom todays levels i weare to avoid the worst impacts o climate change. According to the Nobel Prize-winning

Intergovernmental Panel on Climate Change, we can meet this objective i developedcountries as a whole cut their emissions 2540 % rom 1990 levels by 2020 and at least80 % by 2050.

Audubons PolicyRecommendations

Reduce Global Warming PollutionThe United States should set mandatory limits on global warming pollution and establish

a cap and trade program that is consistent with preventing average global temperaturerom rising another 2 F. Any such program should require pollution permits to beauctioned, use the revenue to ensure a rapid transition to a clean energy economy, andprovide necessary assistance or helping people, wildlie, and ecosystems adapt to climatechanges caused by global warming.

Repower America with Clean and Efcient ElectricityThe United States should strive toward achieving a 100 % clean energy uture by

maximizing energy eciency, vastly expanding our use o renewable energy, anddeveloping the needed inrastructure to deliver clean energy to Americaall in anenvironmentally-responsible manner that will help reduce our global warming emissionswhile minimizing the impacts on birds and habitat. In order to achieve this clean energyvision, Audubon recommends the ollowing rst steps:

Adopt a suite o state and ederal policies designed to increase energy eciency byat least 15 % by 2020.


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Adopt a national renewable electricity standard that will require 25 % o allelectricity to be proved by renewable resources by 2025.

Accelerate the development o properly sited transmission to serve new renewableenergy and a Smart Grid to transmit that energy more eciently.

Reduce Our Dependence on OilIn order to put America on a path toward meeting our goals or reducing globalwarming pollution, the United States should start by cutting our dependence on oil byhal. This can be achieved by signicantly increasing uel eciency or cars and trucks,expanding the use o more uel ecient and less polluting vehicles, using cleaner

and environmentally sustainable uel alternatives, investing in clean transportationinrastructure, public transportation, and sustainable communities, and providingAmericans with more transportation alternatives.

Invest in the Clean Energy Economy o Tomorrow

The United States should make major new investments in clean energy technologiesand inrastructure that will allow us to reduce global warming pollution while also creatingthe clean energy economy o the uture. By limiting global warming pollution and requiring

polluters to pay or their pollution, we can und the necessary investments in energyeciency, clean energy, and technology research and development.

Help Species and

Ecosystems AdaptClimate change is underway and will continue or decades. Actions we take today canlimit the severity o warming and the damage it will bring in the uture. We must helpwildlie and ecosystems adapt to changing new conditions, even as we work to curbclimate change itsel.

Species management and habitat conservation eorts must take into account the habitatshits and ecosystem changes that climate change will inevitably bring. Science-basedmodels like those produced by Audubon Caliornia can identiy habitats that will becomeincreasingly important to the uture survival o birds. In essence, there are three criticalstrategies:

1) we must continue to protect birds and their habitats to maximize population sizesso species will have maximum vigor to withstand the challenges posed by climatechange,

2) we must improve habitat resiliencethe ability o healthy ecosystems to absorbdisturbances and changing conditions without undergoing undamental shits incharacter; and

3) we must support the movement o species and habitats into areas with moresuitable conditions when the other two options are not enough.


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Essential Steps Assessing, prioritizing, protecting, and restoring habitats o regional, national,

continental and global signicance or species survivalthe Audubon/BirdlieInternational Important Bird Areas program is a prime example o such an eort.

Expanding protected area networks, including such places as state and nationalwildlie reuges and sanctuaries to protect species in all parts o the country; andmaintaining healthy habitat corridors to connect them.

Reducing existinghuman-imposed stresses that erode ecosystem resilience suchdevelopment, pollution, habitat ragmentation, and the introduction o invasivespecies.

Policy makers can play a critical role by advancing an agenda to help species and habitats

weather the climate assault. This involves:

Including dedicated unding or natural resources conservation and wildlieadaptation in any comprehensive climate change legislation.

Passing legislation creating new unding sources to help migratory birds and theirhabitats survive climate change.

Integrating global warming adaptation into all wildlie conservation planning,including state Wildlie Action Plans.

Incorporating global warming considerations into public lands planning, such as thedevelopment o Comprehensive Conservation Plans or national wildlie reuges.

Building global warming planning into strategic growth priorities or public landssuch as the Land Acquisition Priority System or national wildlie reuges.

Learn more at www.audubon.org


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2009 National Audubon Society, Inc. All Rights Reserved.

Audubon225 Varick Street7th FloorNew York, NY 10014

Birds and Climate ChangeEcological Disruption in Motion

Audubon Christmas Bird Count and Climate Analysis by

Daniel K. Niven. Ph.D.Gregory S. Butcher, Ph.D.

G. Thomas Bancrot, Ph.D.

Audubon Caliornia Climate Research by

William B.Monahan, Ph.D.

Gary Langham, Ph.D.

birds and climate report

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