Response of Great Tits Parus major to an Irruption of a Pine Processionary Moth Thaumetopoea pityocampa Population with a Shifted Phenology

[摘要] Since1997,apopulationofthePineProcessionaryMothThaumetopoeapityocampaexhibitedashiftedlifecycleinarestrictedareaofamanagedpineforest,atthecentralwestcoastofPortugal.Ratherthanduringtheregularwinterperiod,larvaldevelopmentofthisnovelpopulationoccursduringthesummer.WeindicatethepopulationsaccordinglyastheWinterPopulation(WP)andtheSummerPopulation(SP).WequantifiedthenumericalresponseofGreatTitsParusmajortoirruptionsoftheSP.Intheyearsfollowinganirruption,GreatTitsweremoreabundantintheSParea,thanintwosimilarnon-infestedforestareas.Thiswasparticularlypronouncedduringsummerandautumn,atthetimewhenmoths,eggsandlarvaeoftheSPwereavailableforbirdpredation.AnestboxstudyallowedustoverifythattheSPmothemergenceperiodcoincidedwithegglayingandraisingofsecondbroodsinGreatTits,andhigherreproductiverateswererecordedintheSPthanintheWParea.Toourknowledge,thisisthefirststudytodocumentaresponseofabirdpredatortoalocalT.pityocampairruption,whichwasevenmorespecialasitconcernedaninsectpopulationwithalargeshiftinitslifecycle.OurresultsshowthattheGreatTitisabletorespondtolocaloutbreaksofforestdefoliatorinsects,andwesuggestapotentialimpactofGreatTitpredationonthepopulationdynamicsoftheSP.

[学科分类] 动物科学

[关键词] Food-dependent Breeding Success