Comparative Diurnal and Nocturnal Diet and Foraging in Eurasian Golden Plovers Pluvialis apricaria and Northern Lapwings Vanellus vanellus Wintering on Arable Farmland

[摘要] Knowledgeofdietandintakeratesareusefulfirststepsinunderstandingthedistributionandbehaviourofforagers.ThedietofGoldenPloversandLapwingsfeedingonarablefarmlandhasbeenrarelystudied,yetthesespeciesincreasinglyoccupythishabitatinwinter.Theyareknowntofeedatnightbutlittleisknownabouttheirdietandforagingsuccessatnight.Thisstudyaimedtodescribeandcomparediurnalandnocturnalforagingbehaviourinordertoexplainspatialandtemporalpatternsinforaging.Overthreewinters(1999/2000–2001/02)diurnalandnocturnalobservationsoffocalindividualsandcollectionoffaecalsampleswereusedtoreconstructdietandquantifyintakeratesacrossarangeofarablehabitats.Numerically,arthropods(mostlyCarabidsandmillipedes)werethemaindiurnalpreytypesbutbybiomass,smallearthwormswerethemajorpreyitems.Diurnalintakerateswerelowbutcomparablewithotherstudiesofthesespecies,promptingquestionsconcerningtheprofitabilityoffeedingonagriculturalfarmlandandthepause-travelforagingmode.Nocturnalintakerateswereupto50%higherduetoagreaterrelianceoncatchinglargeearthwormsatnight.Diurnalintakerateswerehighestduringmildweatherandongrassandsugarbeetstubblefields;theywerelowestoncerealcrops,yetthiswasthehabitatmostconsistentlyoccupied.Currentmethodsforassessingearthwormabundancelimitfurtherexplanationofforagingbehaviour.

[学科分类] 动物科学

[关键词] Nocturnal