Responses of breeding Bald Eagles, Haliaeetus leucocephalus, to human activities in northcentral Michigan

Responses of breeding Bald Eagles, Haliaeetus leucocephalus, to human activities in northcentral Michigan.Canadian Field-Naturalist 106(4): 443-453.To characterize disturbance and analyze eagle response, we recorded 714 events of potentially disturbing human activity near six pairs of Bald Eagles (Haliaeetus leucocephalus) breeding in northcentral Michigan in 1990.Vehicles and pedestrians elicited the highest response frequencies, but aircraft and aquatic activities were the most common.Magnitude of response was inversely proportional to median distance-to-disturbance. Seventy-five percent of all alert and flight responses occurred when activity was within 500 m and 200 m, respectively.Adults responded more frequently than nestlings, and at greater distances-to-disturbance when perched away from nests.May was the peak month for human activity, most of which occurred on weekends (60%) and after noon (72%).Classification tree (CART) models are used to assess disturbance-specific response frequencies and to formulate management considerations.