An examination of wood warblers' intersepecific interactions in the forests of northern Michgian

Abstract

Resource partitioning between sympatric wood warblers must occur in order for species coexistence. Our study of Blackburnian, Yellow-rumped, and Black-throated Green Warblers investigates niche differentiation between these species, and seeks to compare the warbler partitioning strategies in northern Michigan mixed forests to boreal forests observed in Maine by Robert MacArthur. We tested whether our focal species differ in the percent of time they utilize various tree species and locations in the tree. We collected data at several sites in northern Michigan, with relatively heterogeneous forest communities, by recording the species of tree, position in tree, and amount of time we observed each warbler. Our data showed no difference in percent time in position in tree between warblers but did show that Black-throated Green Warbler utilized tree species differently, as it had a higher percent time in Northern White Cedar than the other species. Our data suggests that the focal warblers differentiate niche by species of tree in northern Michigan mixed forests.