Density, productivity, diet, and human persecution of Golden Eagles (Aquila chrysaetos) in the central-eastern Italian Alps

A Golden Eagle (Aquila chrysaetos) population of 46 pairs was regularly censused between 1982-92 in a 7800-km(2) study plot in the central-eastern Italian Alps. Density was stable at 5.9 territorial pairs per 1000 km(2). Mean nearest-neighbor distance was 8.7 km (N = 46), and nest areas were regularly dispersed. Sixteen percent of 70 pairs consisted of an adult and a nonadult individual. Mean laying date was 23 March (N = 27). The percentage of successful territorial pairs was 55% (N = 109). Mean number of fledged young was 0.61 per territorial pair (N = 109) and 1.10 per successful pair (N = 56), Diet was dominated by mammals (64%) belonging to the orders Artiodactyla, Rodentia, Lagomorpha, and Carnivora, and by birds (32%) belonging to the order Galliformes (N = 247 prey items). Productivity was affected by age of territory holders and the extent of woodland or grassland within the potential for-aging range. Illegal shooting accounted for thr deaths of 15 individuals between 1980-89. Compared to other alpine populations, the study population showed a low density, average nearest-neighbor distance and productivity, and a typical frequency of nonadult territory holders. We suggest that the future long-term population trends of alpine Golden Eagles will be determined by the interactions among increasing food supply declining availability of foraging habitat, decreasing human persecution, and increasing human disturbance.