Golden Eagles in Denali National Park and Preserve : productivity and survival in relation to landscape characteristics of nesting territories

Graduation date: 2005Denali National Park and Preserve (Denali) contains one of the highest densities of nesting Golden Eagles (Aquila cluysaetos) in North America. Productivity of this migratory population varies both temporally and spatially. Regardless of prey abundance, more fledglings are consistently produced at some nesting territories than others. In many raptor studies, the areas where the most fledglings are produced are often considered the highest quality nesting territories; however, few studies have examined the relationship between productivity and survival of juvenile Golden Eagles. I studied the effects of landscape characteristics of nesting territories on the productivity and survival of Golden Eagle in Denali. I quantitatively described the landscape characteristics including land cover composition, elevation, and terrain ruggedness, surrounding 36 Golden Eagle nesting sites and compared the landscape characteristics between 18 low and 18 high production nesting territories. I also instrumented 48 fledgling Golden Eagles with satellite radio transmitters to estimate the length of the post-fledging dependence period, survival during the post-fledging dependence period, and survival during the first year of independence. I identified 27 unique land cover types within nesting territories and found a negative relationship between the amount of Upland land cover and productivity; the probability of being a high production nesting territory decreased as the amount of the Upland land cover within a nesting territory increased. Satellite telemetry was useful for estimating the length of the post-fledging dependence period, fledgling survival, and first-year survival of Golden Eagles. The post-fledging dependence period of Golden Eagles in Denali is shorter than reported for Golden Eagles in temperate latitudes. Fledgling survival during the post-fledging dependence period was high and counts of fledglings made before actual fledging occurs provide realistic estimates of the reproductive success of Golden Eagles in Denali. First-year survival of Golden Eagles from Denali was lower than survival of Golden Eagles from temperature latitudes. By contrasting several models of survival using program MARK, I found evidence that Golden Eagles from single-fledgling broods had a higher first year survival rate than those from two-fledgling broods. Thus, productivity may not be a good predictor of survival of Golden Eagles in Denali