LONGEVITY OF BALD EAGLES FROM AUTUMN CONCENTRATIONS IN GLACIER NATIONAL PARK, MONTANA, AND ASSESSMENT OF WING-MARKER DURABILITY

摘要

We present data collected subsequent to the publication of McClelland et al. (1994). In that study, 303 Bald Eagles (Haliaeetus leucocephalus) were banded with U.S. Fish and Wildlife Service pop-rivet aluminum leg bands between 1977 and 1993, in Glacier National Park, Montana (GNP). Wraparound patagial wing markers were placed on 121 of the 303 eagles and 66 were equipped with battery-powered VHF transmitters (55 tail mounts and 11 backpacks). With few exceptions, Bald Eagles at autumn concentrationsin GNP came from summering areas in northwestern Canada en route to wintering sites south and west of GNP. The eagles stopped in GNP to feed on spawning kokanee salmon (Oncorhynchus nerha). The kokanee population collapsed in the late 1980s; consequently, there no longer are autumn concentrations of Bald Eagles in GNP (Spencer et al. 1991).