Habitat Use by Three Breeding Insectivorous Birds in Declining Maple Forests

摘要: We studied population variability and habitat use of the Least Flycatcher (Empidonax minimus), Red-eyed Vireo (Vireo olivaceus), Black-throated Blue Warbler (Dendroica caerulescens) in sugar maple (Acer saccharum) forests southern Quebec various state decline. The was most abundant species (1.7 pairs/ha) over three-year study, although numbers were lower showed higher interannual declining stands compared to healthy stands. flycatcher established its territory areas where trees tallest, nearly pure stand, sub-canopy sparse. (1.2 ubiquitous populations stable all study sites regardless Warbler, less (0.4 pairs/ha), colonized stand that offered a high density shrub growth under closed canopy both sites. Except perhaps for flycatcher, there no clear association between change or pattern level forest decline these three species. Confounding factors such as predisposing life-history characteristics large scale changes may explain some our results.