Foraging Habitat Selection in the Last Ortolan Bunting Emberiza hortulana Population in Switzerland: Final Lessons before Extinction

Ardea

Myles H. M. Menz¹  Raphaël Arlettaz²  Paul Mosimann-Kampe³ 

[1] 1 Institute of Ecology and Evolution, Division of Conservation Biology, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland;1 Institute of Ecology and Evolution, Division of Conservation Biology, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland3 Swiss Ornithological Institute, Valais Field Station, Nature Centre, CH-3970 Salgesch, Switzerland4 The Ecology Centre, University of Queensland, St Lucia, QLD 4072, Australia;2 Breiten 37, CH-3232 Ins, Switzerland

关键词: Species Conservation;   

DOI  :  

学科分类：动物科学

来源: Nederlandse Ornithologische Unie/Netherlands Ornithological Union

【 摘 要 】

TheOrtolanBuntingEmberizahortulanahassufferedageneraldeclineacrossmuchofWesternEuropeinrecentdecades.InSwitzerland,onlyonepopulationremainsinsub-Mediterraneanshrub-steppeonthesouth-facingslopesoftheRhôneValley(Valais).WeaimedtocollectdataonforagingecologyofthelastSwissOrtolanBuntingsduringreproduction.However,thispopulationunderwentaconsiderabledecline,withnobreedingconfirmedinSwitzerlandin2007.Weinvestigatedforaginghabitatselectionoffourunpairedmalesatthehabitatandmicrohabitatscales,andcomparedpatternsofforaginghabitatusewithpatternsofterrestrialinvertebrateabundance.Allradio-trackedbirdsforagedexclusivelyontheplain.Theadjacentslope,whichharbouredtheformerbreedinggrounds,wasusedonlyforterritorialsongdisplays.Allmalesshowedadisproportionateuseofconventionalmaizefieldsthathadbeentreatedwithherbicides,whilealsoexhibitinganavoidanceofmeadowsandriparianvegetation.Theseobservedpatternsofhabitatusemaybedrivenbyunavailabilityofoptimalforaginghabitat,withbirdsbeingforcedtousethebestofapoorsetofoptions.Structurally,itwasshownthatbirdsforagedinareaswithahighproportionofbareground,aswellasmoderatelydenseoverheadvegetation.Theseareasdidnotsupporthigherarthropodabundance,suggestingthatfoodaccessibility(and/orcover)ratherthanfoodabundancedictatedhabitatselection.ItremainstobeseenwhetherthesepatternsofmicrohabitatusealsoapplytobreedingOrtolanBuntings.FurtherworkinsouthernEuropeanbreedinggroundsshouldbeenvisionedtogaincrucialinformationabouttheecologicalrequirementsofOrtolanBuntingsinMediterraneanandsub-Mediterraneanhabitats.Additionally,effortneedstobefocusedonidentifyingfactorsaffectingthespeciesonthewinteringgrounds,whichmayassistinexplainingtheobserveddeclinesinthebreedingareas.

【 授权许可】

Unknown