Distribution and at-sea activity of a nocturnal seabird, the Bulwer's petrel Bulweria bulwerii, during the incubation period

• Author(s): Dias, Maria P. ; Romero, Joana ; Granadeiro, José Pedro ; Catry, Teresa ; Pollet, Ingrid L. ; Catry, Paulo
• Date: 2016
• Persistent ID: http://hdl.handle.net/10400.12/4835
• Origin: Repositório do ISPA - Instituto Universitário
• Project/scholarship: info:eu-repo/grantAgreement/FCT/3599-PPCDT/121071/PT ; info:eu-repo/grantAgreement/FCT/5876/147321/PT
• Subject(s): Diel vertica lmigration; Foraging behaviour; Lunar cycle; Procellariiformes; Seabirds
• Document Type: Journal article
• Language: Portuguese
• Contributor(s): Repositório do ISPA

Description

Bulwer'spetrelsarenocturnalseabirdsthatmostlypreyonmesopelagicfauna.Asaerialforagersand shallowdivers,theirfeedingopportunitiesarelimitedbynear-surfaceavailabilityoftheirprey,whichis highlyvariablebothtemporally(reflectingdiurnalandlunarcycles)andspatially.Herewestudiedhow Bulwer'spetrelscopewiththeseconstraintsbyanalysingtheirat-seadistributionandactivityduringthe incubationperiod.Wetrackedthemovementsof20birdsfromSelvagemGrande(NEAtlantic)duringa completelunarcycle,andrecorded30foragingtripsthatlasted11daysonaverage.Birdswereboth distributedaroundthecolonyandinwatersclosetotheAzoreanarchipelago(mid-Atlantic)located 1700kmaway,andweresignificantlymoreactiveatnight(especiallyjustaftersunsetandbeforesunrise), whenmesopelagicfaunaisalsoclosertotheseasurfaceduetotheirdielverticalmigrations.Bulwer's petrelsspentsignificantlymoretime flyingduringmoonlight,althoughtheeffectofthemoonwasrela- tivelyweak(ca.10–15%differencebetweenmoonlitanddarkperiodsofthenight),andnotobviouswhen birdswereforaginginmid-Atlanticwaters,whichwerealsotargetedmoreoftenduringfull-moon.These resultsrevealkeyadaptationsoftheBulwer'spetreltothehighlydynamicecologyofitsmesopelagicprey.

Fundação para a Ciência e a Tecnologia (FCT), European Regional Development Fund