Daily Travel Schedules of Adult Eurasian Hobbies Falco subbuteo — Variability in Flight Hours and Migration Speed Along the Route

Ardea

Thomas Alerstam¹  Raymond H.G. Klaassen¹  Roine Strandberg¹  Patrik Olofsson² 

[1] 1 Department of Animal Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden;2 Furubodavägen 73, SE-29692 Yngsjö, Sweden

关键词: Fly-and-forage Strategy;   

DOI  :  

学科分类：动物科学

来源: Nederlandse Ornithologische Unie/Netherlands Ornithological Union

【 摘 要 】

WeanalysedsatellitetrackingdatatorevealthedailytravelschedulesofHobblesFalcosubbuteomigratingbetweennorthernEuropeandsouthernAfrica.Bycomparingmovementsduringshort-timeintervalsof1–8hatdifferenttimesofthedaybetweenthethreedifferentregionsEurope,SaharaDesertandtropicalAfrica,wefoundsignificanthigherhourlyspeedsintheSaharacomparedtotheothertworegions.Themigrationstartedearlyinthemorningandcontinuedthroughouttheday,resultingindailytraveltimeexceedingthatoftypicalthermalsoaringmigrants.DuetofasthourlyspeedsincombinationwiththelongtraveldaysduringSaharacrossings,theHobbiesexceededdailytraveldistancesrecordedforsoaringmigrants.InEuropeandtropicalAfrica,thespeedwashighlyvariableduringtheday,andlowerflightspeeds,especiallyduringafternoons,suggestafly-and-foragestrategy.Ourpredictionsaboutregularoccurrenceofnocturnalflightespeciallyacrossgeographicalbarriersasthedesertwerenotfulfilled.IntheSahara,theHobbiesrestrictedtheirmovementtodiurnalmigration.Nevertheless,10%oftheflightsegmentsintropicalAfricawerepartlyorcompletelyduringnighthoursandHobbiesoftenstartedtheirdailyflightbeforeoratsunrise.WeattributethespecialcharacteristicsofthedailytravelschedulesofHobbiesprimarilytotheiruseofafly-and-foragestrategy,possiblyincombinationwithpreparednessforexploitingthermalsduringthedailythermaltimewindow.FurtherstudiesareneededtounderstandwhyHobbiesdonotincreasedailytravellinghourstoincluderegularnocturnalflightintheSaharaDesert.WesuggestthatthedailytravelschedulesoftheHobby,whichweredistinctlydifferentfromthoseofotherdiurnalmigrantslikelargeraptors(whichmainlyexploitthermalsoaringmigration)orpipits,wagtails,finchesandpigeons(whichmainlytravelduringthemorninghours)maybetypicalforbirdspeciesthatprimarilyuseafly-and-foragemigrationstrategy.

【 授权许可】

Unknown