Long-term breeding demography and density dependence in an increasing population of Golden Eagles Aquila chrysaetos

摘要: Few studies have quantified the dynamics of recovering populations large raptors using long-term, spatially explicit studies. Using data collected over 37 years in western Italian Alps, we assessed trends distribution, abundance, fecundity and breeding population structure Golden Eagles Aquila chrysaetos. spatial distribution territory centroids 2007, found that eagle territories was over-dispersed up to 3 km. Although size total productivity increased from 1972 2008, proportion pairs laid eggs showed a strong decline, falling no more than 50% after 2003. On average, 15% successful nests produced two fledglings, also declined time. No significant relationship between growth rate detected, but percentage bred success evidence density dependence, as they significantly with increasing density. Our results suggest operating across heterogeneous habitats, is currently regulating this population, while carrying capacity may still be increasing. This explain apparent paradox reduced effort despite productivity.