EFFECT OF REPRODUCTIVE RATE ON MINIMUM HABITAT REQUIREMENTS OF FOREST-BREEDING BIRDS

Abstract

A major challenge facing conservation biologists and wildlife managers is to predict how fauna will respond to habitat loss. Different species require different amounts of habitat for population persistence, and species' reproductive rates have been identified as one of the major factors affecting these habitat-amount requirements. The purpose of this study was to test the prediction that species with higher reproductive rates require less habitat for population persistence than species with lower reproductive rates. We used 41 species of forest breeding birds to test for a relationship between the annual reproductive output and the amount of forest cover at which each species has a 50% probability of presence in the landscape. To look at the presence of species over landscapes with varying amounts of forest cover, we combined two large-scale independent data sets: the North American Breeding Bird Survey and the U.S. Geological Survey (USGS) Land Use and Land Cover (LULC) digital data. Species presence/absence information was determined over a 10-year window for 779 circular landscapes that surround each Breeding Bird Survey route in the central and eastern USA region. Annual reproductive rates were obtained from the literature. There was a significant negative (interspecies) relationship between the estimated minimum habitat amount at which there was a 50% probability of presence in the landscape and annual reproductive output (F1,39 = 7.71, P = 0.008, r2 = 0.16). This is the first direct test for a negative relationship between minimum habitat requirements and annual reproductive rates.