Assessing the impacts of moose-induced habitat change on a forest bird community

Abstract

Forest songbirds are sensitive to habitat disturbances that result in changes to forest structure and composition. In Newfoundland, Canada, browsing by hyperabundant, non-native moose (Alces alces) has caused failed regeneration across extensive areas of forest following disturbance. I examined the impact of these habitat changes at multiple spatial scales on forest bird occurrence and species richness within Gros Morne National Park based on point counts that incorporated both silent intervals and intervals during which black-capped chickadee (Poecile atricapillus) mobbing calls were broadcast. Early successional bird species we more likely to occur with increased failed regeneration on the landscape. Some forest habitat generalists were less likely to occur with increased failed regeneration cover at the local scale. Comparing detection probabilities across silent and playback intervals for 17 species, I found that playbacks increased detection rates for seven species, and either had no effect or decreased detection rates for the remaining ten species.