Phenology, Stopover Dynamics and Population Size of Migrating Black-Tailed Godwits Limosa Limosa Limosa in Portuguese Rice Plantations

Ardea

Pedro M. Lourenço²  Theunis Piersma³  José A. Alves¹  Niko M. Groen²  Julia Schroeder⁴  Rosemarie Kentie²  Jos C.E.W. Hooijmeijer² 

[1] 3 Centre for Ecology, Evolution and Conservation, School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK;1 Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands;1 Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands4 Department of Marine Ecology, Royal Netherlands Institute for Sea Research (NIOZ), PO. Box 59, 1790 AB Den Burg, Texel, The Netherlands;1 Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands2 Current address: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK

关键词: Stopover Duration;   

DOI  :  

学科分类：动物科学

来源: Nederlandse Ornithologische Unie/Netherlands Ornithological Union

【 摘 要 】

Between2005/06and2008/09westudiedBlack-tailedGodwitsLimosaI.limosastaginginthericefieldssurroundingtheTejoandSadoestuaries,Portugal.Godwitswerecountedweeklyandflockswerescannedforcolour-ringedindividuals.Weanalysedphenology,dynamicsofthestopover,andestimatedthesizeofthePortuguesestagingpopulationaswellasthetotalwesternlimosapopulation,GodwitsstartedarrivinginJanuary.NumberspeakedinthesecondhalfofFebruary,afterwhichtheyquicklydepartedfromthearea.Comparisonwithpreviousrecordssuggestedthatnumbershavedecreasedsincetheearly1990s,andthatgodwitscurrentlypeaklaterthansome15yearsago.Individualstagingdurationsaveraged22.6daysin2007and25.3daysin2009,andincreasedtowardstheendofthestagingperiod.Weestimatedthatatotal59200birdsusedtheareain2007and53100in2009.Usingestimatesfortheproportionofcolour-ringedbirdsintheflocks,weestimatedthepopulationsizeofthewesternpartoftheL.l.limosapopulationat133151–140722birds.Thisishigherthanpreviousestimatesbasedoninventoriesofthebreedingpopulation,butaccountsforthenon-breedingsegmentofthepopulation.Thus,weestimatethat38–44%oftheNWEuropeanBlack-tailedGodwitpopulationstageinPortugal.ItisarguedthatprocessesinIberiaarenotlikelytohavecontributedtothepopulationdeclineastheareaforricecultivationhasincreased.Nevertheless,asgodwitsstaginginIberiaaretotallydependentonhuman-madehabitats,changesinricefarmingpracticescouldhavegreatimpactonthetotalpopulationsize.

【 授权许可】

Unknown