Identifying Factors Influencing Presence and Reproductive Success of a Golden Eagle Population in South Central Montana

Abstract

Golden Eagles (Aquila chrysaetos) in the western U.S. have received increased attention due to an apparent decline in the number of annual migrants and expected increased risk from energy development. Long-term research focused on resident, breeding Golden Eagles in this region is rare and sorely needed to assess the degree of population decline. In addition, managers require the identification of factors that influence presence and breeding success of Golden Eagles to create an effective management strategy. Beginning in 2010, we revisited a historically surveyed study site near Livingston, Montana. Our objective was to compare the current status of the Golden Eagle breeding population to that from the 1960’s and to identify factors necessary for maintaining Golden Eagle populations. In the last 3 breeding seasons, we have documented a near 100-percent occupancy rate of historic territories and a marked increase in the number of breeding pairs. Our results also indicate that factors related to prey availability most strongly influenced nest site selection and reproductive success. Based on our current results, we suggest Golden Eagle populations may remain strong in some locations and management strategies should focus on maintaining prey habitat.