SURVIVAL RATES AND POPULATION-DYNAMICS OF BALD EAGLES ON CHESAPEAKE BAY

Survival of 39 radio-tagged bald eagles (Haliaeetus leucocephalus) in the Chesapeake Bay region was 100% in the first year of life. Mean minimum survival per year of all eagles was 91% (95% CI = 86-96%); mean maximum survival was 98% (95% CI = 96-100%). A deterministic life-table model predicted a finite growth rate of 5.8% per year, whereas the growth rate based on the maximum survival estimates was 16.6% per year. The breeding population actually increased 12.6% per year from 1986 to 1990. We estimated the intrinsic growth rate at 6.9% based on natality and minimum survival data and 19.2% based on maximum survival data. Because eagle habitat is being converted to human developments at a rapid rate on the Chesapeake, models incorporating these habitat losses are needed to accurately predict future population trends.