Aspen Bibliography

Title

Habitat use and foraging behavior of four parulid warblers in a second-growth forest

Document Type

Article

Journal/Book Title/Conference

Journal of Field Ornithology

Volume

66

Issue

2

First Page

277

Last Page

288

Publication Date

1995

Abstract

Habitat useand foragingbehax4orof the Chestnut-sidedWarbler (Dendroicapen- sylvanica),CanadaWarbler(Wilsoniacanadensis)M,ourningWarbler(Oporornisphiladel- phia) and NashvilleWarbler (Veq'mivorrauficapilla)were studiedin a second-growthforest in northern Wisconsin(USA) during the breedingseason.Our objectivewasto determine if interspecificand intersexualforaging differencesexistamong thesespecies.The warblers concentratedforaging activitieson a few speciesof trees and shrubs.Compared to other speciesC,anadaWarblersmorefrequentlyusedconiferoustreesthatwerescatteredthrough the primarilydeciduoushabitat.All speciesmostfrequentlyusedbranchesof trees,but male NashvilleWarblersalsomade considerableuse of leavesand twigs.Warblersforaged at a varietyof heightsin the vegetation,with male NashvilleWarblersforaginghighestin the nfidstoryand canopyof mature trees.Femalesof all speciestended to be activelower in the vegetationthan males.Gleaningwasthe mostfrequentlyusedforagingmethod, exceptfor male CanadaWarblers,which usedforagingmethodsinvolvingflight in about 70% of prey pursuits.When 30 foraging-relatedcharacterswere consideredsimultaneouslyin a multivar- iate analysisi,t wasfound that intersexualdifferenceswithin a specieswere lesspronounced than interspecificdifferences,except NashvilleWarbler males,which were distinctin their foraging.Whendesigningaconservationstrategyforthesespeciesb,iologistsmustrecognize that thesebirds require heterogenoussecond-growthforests