RESPONSES OF BREEDING BALD EAGLES, HALIAEETUS-LEUCOCEPHALIS, TO HUMANACTIVITIES IN NORTHCENTRAL MICHIGAN

To characterize disturbance and analyze eagle response, we recorded 71 4 events of potentially disturbing human activity near six pairs of Ba ld Eagles (Haliaeetus leucocephalus) breeding in northcentral Michigan in 1990. Vehicles and pedestrians elicited the highest response frequ encies, but aircraft and aquatic activities were the most common. Magn itude of response was inversely proportional to median distance-to-dis turbance. Seventy-five percent of all alert and flight responses occur red when activity was within 500 m and 200 m, respectively. Adults res ponded more frequently than nestlings, and at greater distances-to-dis turbance when perched away from nests. May was the peak month for huma n activity, most of which occurred on weekends (60%) and after noon (7 2%). Classification tree (CART) models are used to assess disturbance- specific response frequencies and to formulate management consideratio ns.