The Connectivity of Spring Stopover Sites for Geese Heading to Arctic Breeding Grounds

[摘要] Duringthespringmigrationarctic-breedinggeesepauseintemperateandsubarcticstagingareasinordertodepositbodyreservesforbreeding.FocusingonasinglearcticstopoversiteinWest-Spitsbergen,Svalbard,Norway(VÃ¥rsolbukta,77°45′N,14°24′E),behaviouralstrategiesofBarnacleGeeseBrantaleucopsiswereinvestigatedandbodyconditionandpresenceofindividuallymarkedbirdsrecorded.Individualsusingdifferentstagingareasearlieralongthemigrationroute(HelgelandandVesterÃ¥lenontheNorwegianmainland)andheadingtodifferentbreedingcolonies(theclose-byNordenskiöldkysten,andthedistantKongsfjorden)werecomparedduringsprings2003–05.BirdsinVesterÃ¥lenleftthestagingareaearlierthanthoseinHelgeland,andarrivedearlierinVÃ¥rsolbuktaaswell.InVÃ¥rsolbukta,femalesgainedbodyconditionatasimilarrateregardlessoftheircolonyaffiliation,whereasmalesfromNordenskiöldkystenexhibitedasmalleroverallincreaseinconditioncomparedtomalesfromKongsfjorden.TheKongsfjordenbirdsstayedforashorterperiod(average2.8days)thanthosefromNordenskiöldkysten(average4.0days).NordenskiöldkystenbirdsfrequentlyleftVÃ¥rsolbuktaforshortperiodspresumablyvisitingthebreedingareainordertooptimisenestinitiationwithrespecttoprevailingsnowconditions.ThedateoffinaldeparturewasalsocorrelatedwithnestinitiationdateatNordenskiöldkysten.NosuchrelationshipfortheKongsfjordenbirdswasfound.Wesuggestthatthegeeseadopta‘hopping’strategy,usinganetworkofstopoversitesinSvalbardduringspringwithalaststopoveratabufferareaintheproximitytothebreedingarea.Forthisvulnerablepopulationitisimportanttoidentifythesitesformingthelinksinthischain,andtoestablishtheirfunctionandutilisationbygeeseduringthevitalprebreedingperiod.

[学科分类] 动物科学

[关键词] Branta Leucopsis