Geographical Patterns in Primary Moult and Body Mass of Greenshank Tringa nebularia in Southern Africa

Ardea

Les G. Underhill¹  Magdalena Remisiewicz²  JarosÅ‚aw K. Nowakowski³  Anthony J. Tree⁴ 

[1] 2 Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch, 7701, South Africa 4 Marine Research Institute, University of Cape Town, Rondebosch 7701, South Africa;1 Bird Migration Research Station, University of GdaÅ„sk, ul. Wita Stwosza 59, 80–308 Gdansk, Poland 2 Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch, 7701, South Africa;1 Bird Migration Research Station, University of GdaÅ„sk, ul. Wita Stwosza 59, 80–308 Gdansk, Poland;3 P.O. Box 2793, Port Alfred, 6170, South Africa

关键词: Southern Africa;   

DOI  :  

学科分类：动物科学

来源: Nederlandse Ornithologische Unie/Netherlands Ornithological Union

【 摘 要 】

GreenshanksTringanebulariashowvariouspatternsofprimarymoultinthenorthernhemisphere,butfarthersouthmoultpatternsareknownonlyfragmentarily.WeIdentifiedgeographicalpatternsinprimarymoultandpre-migratoryfatteningofGreenshanksontheirsouthernmostAfricannon-breedinggrounds.Wecomparedprimarymoult(usingUnderhill-Zucchinimodels)andbodymassatapopulationlevelbasedon356Greenshankscaughtin1968–1998atinlandwetlandsinZimbabwe,andontheeastandwestcoastsofSouthAfrica.About20%ofimmaturesreplacedonetofiveouterprimariesinDecember—May,ararepatterninthenorth.Sub-adultsmoultedallprimariesonaverage40daysearlierthanadults,yetatthesamerate.Adultsstartedprimarymoultonaverage16–19daysearlierinZimbabweandattheeastcoastthanatthewestcoast(7,4,23September,resp.).ThesedatescorrespondwiththeGreenshanks'broad-frontarrivalinZimbabweandtheeastcoast,andtheirlaterarrivalatthewestcoast.Moulttook10–17dayslongeronaverageinZimbabweandattheeastcoastthanatthewestcoast(122,115,105days,resp.),thustheendofmoultcoincidedwithinsixdays(31December—6January).Pre-migratoryfatteningbeganabout13–19Januaryacrossallregions.Themeandeparturefatloadsofadultswere76gInZimbabwe,116gatthewestcoastand125gattheeastcoast.TheheaviestadultsfromallthreeregionscouldreachtheNileValleyortheRedSeacoastinonenon-stopflight.WesuggestthatGreenshanksatinlandwetlandsofZimbabwebenefitfromashorterreturnmigrationdistanceandlowercompetitionthanatthecoasts,andabundantfoodduringtheentireaustralsummerInfavourableyears,butcanmoveontothecoastsifconditionsdeteriorate.

【 授权许可】

Unknown