Pre-Migratory Movements of Adult Montagu's Harriers Circus pygargus

[摘要] Pre-migratoryandmigratorymovementsofMontagu'sHarrierCircuspygargus,along-distancemigrant,arepoorlydocumentedbyringrecoveriesandobservations.Inthepresentstudy,wetagged10adultMontagu'sHarriersinNESpainwithsatellitetransmittersandtrackedtheirmovementsuntiltheirarrivalonthewinteringgrounds.Toidentifytheendofthebreedingseasonandtheonsetofthemigrationbasedonoursatellite-telemetrydatawedevelopedandappliedastatisticalapproach,definingthetimeperiodbetweenthesetwoeventsasthepre-migratorystage.Wethencomparedhabitatpreferencesduringthebreedingseasonandthepre-migratorystage.Thedurationofthepre-migratorystageaveraged42days,withharriersleavingthebreedingareasbetween4Juneand27July,andtheonsetofthemigrationtakingplacebetween25Julyand4September.Stagingareasusedduringpre-migrationwerelocatedathigheraltitudesthanthebreedinggrounds,andwerecharacterizedbythepresenceofshrublandsandcultivatedareas,mainlycereals.Montagu'sHarriers'useofthesesitesislikelytoberelatedtofoodavailability:athigheraltitudes,peakabundanceofOrthoptera,theirmainpreysource,occurslaterintheseasonthaninthelowlandbreedingarea.Pre-migratorymovementsmayalsoplayanimportantroleinthesearchforsuitablebreedingsitesforfutureuse.

[学科分类] 动物科学

[关键词] Staging Areas