BALD-EAGLE POPULATION IN PRINCE-WILLIAM-SOUND AFTER THE EXXON-VALDEZ-OIL-SPILL

We initiated studies to determine whether the Exxon Valdez oil spill i nfluenced bald eagle (Haliacetus leucoephalus) demography in Prince Wi lliam Sound (PWS), Alaska. Using fixed-wing aircraft, we surveyed bald eagle populations within random plots once each year and censused nea rly all islands in PWS in 1989-91 and 1995 to estimate population size . We calculated population indices (uncorrected for birds not seen) of 2,199; 1,935; 2,116; and 2,641 adult eagles for the 4 years studies. Subsequent to the 1989 oil spill, the eagle population returned to its estimated pre-spill size by 1995. The PWS bald eagle population has i ncreased at an average annual rate of 3.7% from 1982 to 1995. The prop ortion of immatures in the population averaged 29% and did not vary si gnificantly among years.