Female-Biased Sex Ratio in Moulting Black-Necked Grebes Podiceps nigricollis in Southern Spain

Ardea

Marta I. Sánchez¹  Nico Varo¹  Andy J. Green¹  Juan A. Amat¹  Cristina Ramo¹ 

[1] Department of Wetland Ecology, Estación Biológica de Doñana (EBD-CSIC), Calle Américo Vespucio s/n, E-41092 Sevilla, Spain

关键词: Waterbirds;   

DOI  :  

学科分类：动物科学

来源: Nederlandse Ornithologische Unie/Netherlands Ornithological Union

【 摘 要 】

WetestedifBlack-neckedGrebe,aspeciesinwhichbothsexesundertakemoult-migration,haveanunbiasedsexratioatamoultingsiteinEurope,aspreviouslyfoundinNorthAmericaandaswasexpectedforaspecieswithbiparentalcare.Forthisweusedauniquelong-termdatasetof5821grebescapturedforringingthroughoutthemoultingseasonsof2006–2012intheOdielsalt-marshes(SWSpain).Thegrebesweresexedandclassifiedasadults(74%)orjuveniles(26%).BirdsringedatOdielwererecoveredoverawideareauptocentralRussiaandsouthtotheCanaryIslandsandMorocco.Wereportonauniquecaseofastronglybiasedsexratioinamoult-migratingbirdspecieswithbiparentalcare,inwhichadultfemalesweresignificantlymoreabundantthanadultmalesinall7years(1.6–4.2femalespermale).Biasedsexratioswerenotfoundamongjuveniles.DifferencesbetweenNorthAmericaandEuropeinthesexratiosofadultBlack-neckedGrebesatmoultingsitesmaybeexplainedbythemuchlargerAmericanmoultingsites,whichwouldfacilitateanunbiasedsexratioinNorthAmerica,butnotinEurope.MoultingsitesinEuropemayreachcarryingcapacitybecauseoftheirsmallersize,forcingthelatemigratingindividuals(adultfemalesandjuveniles)tomovelongerdistancestositesfartherfrombreedingareas,suchustheOdielsalt-marshes.

【 授权许可】

Unknown