FIDELITY OF MIGRANT BALD EAGLES TO WINTERING GROUNDS IN SOUTHERN COLORADO AND NORTHERN NEW-MEXICO

Ten of 36 Bald Eagles (Haliaeetus leucocephalus) color-marked in a Col orado wintering area were found there during subsequent winters, where as only one was known to winter elsewhere. Four adult eagles returned to the same winter ranges on which they had been radio-tracked during the winter of their capture, one color-marked adult was seen near its capture site for six succeeding winters, and a banded adult was found dead 3 km from its winter capture site 10 yr later. Percent of marked adults observed in subsequent years in the same wintering area was equ ivalent to that of immatures, but mean number of years adults were see n post-marking was greater, indicating traditional use of wintering gr ounds by adults. Breeding grounds of some adults from a southern Color ado wintering population were at least 1900 km north in cast-central S askatchewan and western Manitoba, Canada.