Fine-Scaled Orientation Changes in Migrating Shorebirds

Ardea

Martin Green¹  Thomas Alerstam¹  Johanna Grönroos¹ 

[1] 1 Department of Biology, Lund University, Ecology Building, SE-223 62 Lund, Sweden

关键词: Ring Recoveries;   

DOI  :  

学科分类：动物科学

来源: Nederlandse Ornithologische Unie/Netherlands Ornithological Union

【 摘 要 】

Flightdirectionsandroutesofmigratingbirdsaredeterminedbythebirds'compassorientation,butalsobyeffectsofwind,socialinfluence,responsestotopographyandlandmarks,andtonavigationcues.WeinvestigatedtheorientationandroutestakenbyarcticshorebirdsduringautumnmigrationinsouthernSwedenatthreedifferentsitessituatedwithinadistanceof200kmfromeachother,inrelationtothebirds'destinations.Weusedthreedifferentmethods,visualtelescopeobservations,trackingradarregistrationandringrecoveries.Meantrackdirectionsdifferedsignificantlybetweenthedifferentsitesinawaythatdemonstratedfine-scaledorientationchangeswhentheshorebirdspassedthesouthernBalticregion.Thegradualchangecannotbeexplainedbydifferentwindconditionsatthedifferentsitesorbydistinctresponsestospecifictopographicalfeatures,i.e.thebirdswerenotfollowingcoastlinesorprominentlandmarksinanydetailedway.Neithercoulditbereconciledwithorientationaccordingtoanyofthemaincompassmechanismsknowntobeusedbymigratingbirdswhichindicatesthatthecontrolofflightcoursesandpathsmaybemorecomplexthanexpected.Theshorebirdsmighttravelwithinaslightlywindingflightcorridorinbroadagreementwiththelarge-scaletopographytomaximizegeneralassociationwithcoastalhabitatsduringmigration.Juvenilebirdshadasignificantlydifferentorientationthanadults,particularlywhenthejuvenilestravelledinflockswithoutanyadults.Juvenilebirdsmaylearnthegeneralflightpathsandcoursechangesinrelationtothelarge-scaletopographyfromolderandexperiencedindividualsintheflocks,butmostofthislearningprocessbetweengenerationsprobablydoesnottakeplaceuntilafterthebirds'firstautumnmigration.

【 授权许可】

Unknown