Where Birds Chill: An Assessment of the Habitat Preferences of Birds Overwintering in Hudson Valley Forests

Many avian species overwinter in eastern North America; however, studies on bird populations are rarely undertaken during this critical survival time, and little is known as to their habitat preferences and foraging behavior. In this observational study, we performed a survey of birds overwintering in the Hudson Valley’s temperate, primarily-deciduous forests, assessing avian populations’ habitat preferences through the vegetative structural variables surrounding overwintering birds as they forage. Our results suggest that high canopy cover is critically important to predicting overwintering bird occupancy on a microhabitat scale. Moreover, overwintering birds preferentially occupy forest plots not dominated by sugar maples, in spite of the fact that sugar maples were the most prevalent tree species surveyed. While shrub and forb cover is not predictive of individual bird occupancy, higher understory cover does influence abundance, suggesting flocking bird species are selective of high ground cover microhabitats. Our results provide critical data on seasonal avian habitat preferences in the face of globally declining avian populations and shifting anthropogenic land use patterns. These results have numerous indications on effective bird conservation over the fall-to-winter season; with further implications in the fields of forest management and white-tailed deer control.