Distribution and Productivity of Nesting Bald Eagles in Washington, 1981-1985

Nesting surveys to determine the distribution and productivity of Bald Eagles (Haliaeetus leucocephalus) in Washington were conducted from 1981 through 1985. Number of known territorial pairs increased from 124 in 1981 to 227 in 1985. Comparisons between the results of this study and Grubb's 1975 study suggest that nesting Bald Eagles are increasing in number. Productivity was estimated using two methods. Productivity, as estimated by direct calculation, averaged 0.87 young per territorial pair. Data subsets utilizing the Mayfield-40% model produced an average productivity estimate of 0.59 young per territorial pair. Washington's mean produc- tivity was lower than in many other regions. The proportion of pairs breeding was high in comparison with Alaska, where low breeding rates may indicate saturation of available habitat.