WaterbirdcolonycountatLakeUrema,ParqueNacionaldaGorongosa

Mozambique,MarchandApril2019

JasonDenlinger,Dr.MarcStalmans,Dr.TaraMassad,

April2019

1

PhotosTaraMassad

Tableofcontents

Pagenumber

Summary 3

1.Surveymethodology 7

2.Results 8

2.1Nestnumbersrecorded 8

2.2Species-by-speciesresults 11

2.3AddiOonalspeciesobservaOons 18

3.Discussion 19

4.References 21

5.Acknowledgements 22

2

Summary

•  AdetailedcountofthewaterbirdcolonyattheedgeofLakeUremawasconductedon12Marchandon16April2019.Thecountwasconductedinthesameareaandaccordingtothesameproceduresasapreviouscounton7April2014.

•  Todate,onlythreesystemaOccountsofthiswaterbirdcolonyhavebeendocumented.

•  Thecolonywaslocatedatthesouth-eastcornerofLakeUrema(Fig.1)andextendedacrossadistanceof1.6kmfrom18.89996S;34.49986Eto18.91015S;34.51075E(coveringapproximately15ha).

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Fig.1.MapofGorongosaNa<onalPark,Moçambique,showingtheloca<onofLakeUremaandthewaterbirdbreedingcolony

(Stalmansetal.2014).

Summary-con<nued

•  On14March,CycloneIdai,acategory2cyclone,madelandfallalongthecoastofBeira,MoçambiquefellingtreesandcausingwidespreadfloodingwithinGorongosaNaOonalPark(GNP).SatelliteimagesshowtheincreaseinsurfaceareaofLakeUremaandoverflowofconnectedrivers.

•  Thisreportcomparestheresultsofthepre-andpost-cyclonecountsconductedin2019,MarchandAprilrespecOvely.ItalsocomparestherecentcountwiththeearliercountofApril2014.

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Fig.2.Satellitedetectedwatersextents,asof19and20March2019overSofalaprovince,GNPandLakeUrema

(sources:AtmosphericandEnvironmentalResearch&AfricanRiskCapacity&UNOSAT).

Summary-con<nued

•  On12March2019atotalof2,432nestsof7differentspecieswerecounted.

•  On16April2019,atotalof3,791nestsof7differentspecieswerecounted.

•  Thisrepresentsanincreasein1,359nestsfromtheearlierMarchcountdespitetheimpactsofCyloneIdai’slandfallintheregion.

Species Mar-19 Apr-19

African Darter Anhinga rufa 722 671

Reed Cormorant Phalacrocorax africanus 191 741

White-breasted Cormorant P. lucidus 189 308

Great Egret Egretta alba 112 99

Black-headed Heron Ardea melanocephala 9 0

Grey Heron A. cinerea 0 42

African Sacred Ibis Threskiornis aethiopicus 0 0

African Openbill Anastomus lamelligerus 581 1034

Yellow-billed Stork Mycteria ibis 628 896

Total nests (all species) 2432 3791

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Table1:side-by-sidecomparisonofthenumbersofwaterbirdnestsinthesamecolonybetween

MarchandAprilof2019.

Summary-con<nued•  However,therewere1,212fewerbirds

countedinApril2019comparedtoApril2014withthelowernumbersmostlytheresultoffewerReedCormorantsbeingpresent.

•  InApril2014therewere5,003nestscountedin463treescomparedtothe3,791nestsfoundin382treesduringtheApril2019count.

•  Themostnumerousspeciesobservedin2019weretheAfricanopenbill,whilein2014therewerefarmoreReedcormorantthananyotherspecies.

•  ThewaterbirdcolonyonLakeUremaconOnuestorepresentoneofthemostimportantconservaOonvaluesofGorongosaNaOonalPark.Theearly-seasonfloodingaswellasthesubsequentaddiOonalfloodingcausedbythecyclonehavecreatedexcellentcondiOonsforasuccessfulbreedingseason.

Species Apr-14 Apr-19

African Darter Anhinga rufa 547 671

Reed Cormorant Phalacrocorax africanus 2276 741

White-breasted Cormorant P. lucidus 230 308

Great Egret Egretta alba 330 99

Black-headed Heron Ardea melanocephala 0 0

Grey Heron Ardea cinerea 82 42

African Sacred Ibis Threskiornis aethiopicus 24 0

African Openbill Anastomus lamelligerus 531 1034

Yellow-billed Stork Mycteria ibis 983 896

Total nests (all species) 5003 3791

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Table1:side-by-sidecomparisonofthenumbersofwaterbirdnestsinthesamecolonybetween

April2014andApril2019.

1.  Surveymethodology

AllnestswereindividuallycountedpernesOngtreeandperspeciestotheextentpossible.Insomecasestreesweregroupedtogetherwhendifficulttodiscernthedifferencesbetweennestsonbrancheswithincloseproximitytoeachother.Nestswerecountedfromaboatwithinca20–100mofthecolony.Ateamof5observerswereusedinboththeMarchandAprilcounts.

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Fig.3.BoatusedtovisitwaterbirdbreedingcolonywithfloodedFaidherbiatreesinthebackground(photoJasonDenlinger)

Fig.4.RepresentaOveviewoftheLakeUremawaterbirdbreedingcolony.SpeciespicturedincludeOpenbillstork,Yellow-billedstork,andGreategret(photoJasonDenlinger)

2.Results2.1Numbersofnestsrecorded

Table3.ResultsofcountofcolonialwaterbirdsbreedingatLakeUrema,GorongosaNa<onalPark,on12March,2019.

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Species No. of nests No. of trees with

nests Average nests/tree Max. nests per tree African Darter Anhinga rufa 722 126 5.7 44 Reed Cormorant Phalacrocorax africanus 191 21 9.1 45 White-breasted Cormorant P. lucidus 189 49 3.9 21 Great Egret Egretta alba 112 45 2.5 10 Black-headed Heron Ardea melanocephala 9 6 1.5 3 Grey Heron A. cinerea 0 0 0 0 African Sacred Ibis Threskiornis aethiopicus 0 0 0 0 African Openbill Anastomus lamelligerus 581 138 4.2 31 Yellow-billed Stork Mycteria ibis 628 147 4.3 29

Total (all species) 2432 340 7.2 45

Table4.ResultsofcountofcolonialwaterbirdsbreedingatLakeUrema,GorongosaNa<onalPark,on16April,2019.

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Species No. of nests No. of trees with

nests Average nests/tree Max. nests per tree African Darter Anhinga rufa 671 108 6.2 25 Reed Cormorant Phalacrocorax africanus 741 76 9.8 41 White-breasted Cormorant P. lucidus 308 56 4.3 19 Great Egret Egretta alba 99 37 2.7 6 Black-headed Heron Ardea melanocephala 0 0 0 0 Grey Heron A. cinerea 42 37 1.1 4 African Sacred Ibis Threskiornis aethiopicus 0 0 0 0 African Openbill Anastomus lamelligerus 1034 147 7 27 Yellow-billed Stork Mycteria ibis 896 187 4.8 29

Total (all species) 3791 382 9.9 70

Table5.ResultsofcountofcolonialwaterbirdsbreedingatLakeUrema,GorongosaNa<onalPark,on7April2014.

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Species No. of nests No. of trees with

nests Average nests/tree Max. nests per tree African Darter Anhinga rufa 547 118 4.6 25 Reed Cormorant Phalacrocorax africanus 2276 219 10.4 53

White-breasted Cormorant P. lucidus 230 54 4.3 22

Great Egret Egretta alba 330 131 2.5 12

Black-headed Heron Ardea melanocephala 0 0 0 0

Grey Heron A. cinerea 82 66 1.2 3

African Sacred Ibis Threskiornis aethiopicus 24 4 6 12

African Openbill Anastomus lamelligerus 531 112 4.7 13

Yellow-billed Stork Mycteria ibis 983 259 3.8 23

Total (all species) 5003 463 10.8 58

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0

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2014 2019

AfricanDarterNestsinApril

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March April

AfricanDarterNests20192.2Species-by-speciesresultsAfricandarternestswerethemostnumerousinMarch,butbyApril2019hadbeenoutnumberedbyseveralotherspecies.

However,thedarternestsdecreasedonlyslightlybetweenMarchandAprilwhileothersincreasedmoresignificantly.ThepresenceofnumerousnearlyfledgingdarterchicksindicatethatthesenestsweremostlynotnegaOvelyaffectedbythecyclone

Therewere124moredarternestsin2019thanin2014represenOnga23%increase.

Fig.5.Africandarter(photoTaraMassad)

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March April

ReedCormorantNests2019TherewerealmostfourOmesasmanyReedcormorantnestspresentinAprilthanMarchof2019.

Despitethis,therewere1,535fewerReedcormorantnestsinApril2019whencomparedtoApril2014.

Thisspeciesalonemakesupfortheoveralldecreaseinnestsbetween2014and2019;with5003and3791nestsrespecOvely.

Fig.6.Reedcormorant(photoTaraMassad)

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2400

2014 2019

ReedCormorantNestsinApril

ThenumberofWhite-breastedcormorantnestsdidnotfluctuategreatlybetweenMarchandApril

of2019norwhencomparingyears2014and2019.

However,therewasanincreaseby63%from

MarchtoAprilof2019.

Therewere34%moreWhite-breastedcormorants

inApril2019thanApril2014.

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March April

White-breastedCormorantNestsin2019

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2014 2019

White-breastedCormorantNestsinApril

Fig.7.White-breastedcormorants(photoTaraMassad)

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Only13moreGreategretnestswereobservedinMarchthanAprilof2019.

ThenumberofGreategretnestscountedin2014werealmostthreeOmesasmanyasin2019.

Fig.8.Greategrets(photoTaraMassad)

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2014 2019

GreatEgretNestsinApril

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March April

GreatEgretNestsin2019

Duringthe2014surveytherewerenoBlack-headedheronnestsobserved.InMarchof2019

therewereninenestsofthisspeciesobserved.

However,uponreturningagaininApril2019there

werenolongeranynestsofthisheronspecies.

ItcouldbethattheBlack-headedheron’swere

displacedbyGreyheronswhichwerenotpresent

duringtheMarch2019count.LaterinApril

2019,42Greyheronnestswerecounted.

However,therewerenearlyhalfasmanyGrey

heronnestsobservedin2019aswerecountedin

2014.

Furthermore,noAfricansacredibiswereobserved

duringeithercountin2019,whereas24were

observedin2014.

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2014 2019

GreyHeronNestsinApril

Fig.9.Greyheron(photoTaraMassad)

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2014 2019

AfricanOpenbillNestsinApril

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March April

AfrianOpenbillNests2019ThenumberofAfricanopenbillnestscountedinApril2019nearlydoubledcomparedtothosecountedinMarchof2019.

Openbillsshowedthegreatestincreaseofallspeciesin2019comparedto2014withalmosttwiceasmanynestsobservedinApril2019.

Fig.10.Africanopenbills(photoTaraMassad)

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0100200300400500600700800900

1000

2014 2019

Yellow-billedStorkNestsinApril

01002003004005006007008009001000

March April

Yellow-billedStorkNestsin2019ThenumberofYelllow-billedstorknestsincreasedapproximately43%fromMarchtoApril2019.

Yellow-billedstorknestsdecreasedbylessthan10%from2014to2019.

Thisspecieshasbeenthe2ndmostpopulousinthecolonyduringeachcount.

Fig.11.Yellow-billedstorks(PhotoTaraMassad)

2.2.Addi<onalspeciesobserva<ons19Southern-maskedweavernestswereobserved

hangingfromthetreesinMarch,butabsentin

Aprilof2019.

SeveralPink-backedpelicanswereobservednear

thecolony,butnotwithnests(Fig.12).

VariousraptorsincludingAfricanfisheagles,a

MarOaleagle(Fig.13),andanAfricanharrierhawk

werecauseforalarmcallsamongstthewaterbirds.

Baboonswereseenpreyinguponeggswithin

nestsofthecolony(Fig.14).Atleastonecrocodile

wasseenlurkingbelowwaiOngforanyfledglingsthat

mightdropintothewatersbelow.

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Fig.13.MarOaleagle(photoTaraMassad)

Fig.12.Pink-backedpelicans(photoTaraMassad)

Fig.14.Baboonraidingnests(photoJasonDenlinger)

3.Discussion

Thebirdsnestedinopen,floodedwoodlanddominatedbyanatreesFaidherbiaalbida,fevertreesAcaciaxanthophloeaandpaper-barkacaciasA.sieberana.OnlyF.albidatrees(Fig.15)seemedtobeusedfornesOng(Stalmansetal2014).

DuringthemostrecentsurveyamaximumoffivenesOngspecieswererecordedperbreedingtree.Themaximumnumberofnestsrecordedforasingletreewas70,mostlyReedcormorants.

While51fewertreeswereusedfornesOngajerCycloneIdai(April2019)thanbeforethecyclone(March2019),therewasa56%increaseintheoverallnumberofnestscountedpost-cyclonewithoverhalfofthespeciesobservedincreasinginnumber.Furthermore,nofallentreesordebriswereobservedintheareaofthecolonyimplyingthatCycloneIdaihadnodirectimpactontheoverallnesOngofthecolony.

Total (all species) by survey No. of nests

No. of trees with nests

Average nests/tree

Max. nests per tree

7 Apr-14 5003 463 10.8 58

12 Mar-19 2432 434 5.6 45

14 Mar-19 Cyclone Idai makes landfall

16 Apr-19 3791 383 9.9 70

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Fig.15.FloodedFaidherbiatreeswithnests(photoTaraMassad)

Table5.Totalwaterbirdnestsandtreeswithnestscountedineachsurveyforthesamecolony.

However,therewere24%fewertotalnestscounted

inApril2019comparedtoApril2014withoverhalfof

thespeciescounteddecreasinginnumber.WhilethemostrecentcountrevealedfarfewerReed

cormorants,theAfricanopenbillincreasedsignificantlycomparedto2014.

Assumingthateachnestrepresentedapairofbirds,theUremacolonycontainedapproximatelyjustover

7,500breedingwaterbirdsinApril2019comparedtoapproximately10,000inApril2014.

Perhapsthisdecreaseinwaterbirdscomparedto

the2014countwasimpactedbytheeffectsof

CycloneIdaioritmaybeanormalfluctuaOon

causedbyotherenvironmentalfactors.Eitherway

thispointstotheneedandimportanceofregular

countstoevaluatethestatusofthiswaterbird

breedingcolony.

Sincethe2014counttwospeciesconOnuetoexceed

the1%Ramsarcriterion.ThecountofAfricandarter

nestsof671(equaOngto1,342birds)exceedsthe1%Ramsarthresholdforthisspeciesinsouthernand

EasternAfrica(100birds;WetlandsInternaOonal2012).Despiteasmalldecreaseinthecountof

Yellow-billedstorkneststo896nests(equaOngto

1,792birds);thisnumberalsoexceedsthe1%Ramsarthresholdforsub-SaharanAfrica(1,000birds;

WetlandsInternaOonal2012).

TheimportanceofGorongosaNaOonalParkasa

conservaOonareaconOnuestobehighlightedbythepresenceofthismajorwaterbirdbreedingcolony.

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4.References

STALMANSM.,DAVIESG.B.P.,TROLLIPJ.&POOLEG.2014.AmajorwaterbirdbreedingcolonyatLake

Urema,GorongosaNaOonalPark,Moçambique.DurbanNaturalScienceMuseumNovitates37:54-57.

UNITAR-UNOSAT.Mozambique,SofalaProvince.Imageryanalysis:19and20March2019,Published20

March2019,Version1.0.

WETLANDSINTERNATIONAL.2012.WaterbirdpopulaOonesOmates5:PopulaOondetails,esOmates,andtrends,www.wpe.wetlandsinternaOonal.org/lmaps

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5.Acknowledgements

Thetwowaterbirdnestcountsconductedin2019wouldnothavebeenpossiblewithoutinput

andassistanceofseveralpeople.Theauthors

wouldliketothankthefollowing:

•  BoatcaptainTestMalungaforhiseffortinmaneuveringtheboataroundnesOngtreeswhilealsousinghisguidingknowledgetocountwaterbirdnests;

•  CelinaDias,BertaGuambe,andJoséMonOnhofortheircontribuOonsincounOnganddatarecordingofnests.

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