. The Canadian field-naturalist. 550 The Canadian Field-Naturalist Vol. 104 Sound. Rockfish and Starry Flounder were the principle fish prey items, while mammals and invertebrates were poorly represented. Our findings agree with the generalization that coastal nesting Bald Eagles feed more on birds than on other taxa, and that nests located in other than coastal areas show a higher proportion offish remains (Chrest 1964; Retfalvi 1970; DeGrange and Nelson 1982; references in Todd et al. 1982; Cash et al. 1985; but see Grubb and Hensel 1978). Seabirds made up a majority of the bird species foun
. The Canadian field-naturalist. 550 The Canadian Field-Naturalist Vol. 104 Sound. Rockfish and Starry Flounder were the principle fish prey items, while mammals and invertebrates were poorly represented. Our findings agree with the generalization that coastal nesting Bald Eagles feed more on birds than on other taxa, and that nests located in other than coastal areas show a higher proportion offish remains (Chrest 1964; Retfalvi 1970; DeGrange and Nelson 1982; references in Todd et al. 1982; Cash et al. 1985; but see Grubb and Hensel 1978). Seabirds made up a majority of the bird species found in prey remains and Bald Eagles use a variety of methods to capture them, including team-hunting, excavating nesting burrows, surprise, and pirating {references in Todd et al. 1982; DeGrange and Nelson 1982; Angell and Balcomb 1982). Our fish collections contained few vertebrae but a large number of skulls. This suggests eagles fed on fish heads discarded by fishermen, a behavior that has been reported elsewhere (Dunstan and Harper 1975; Todd et al. 1982; Cash et al. 1985). Alternatively, fish skulls may have appeared in the collections more often because they were less digestible and persisted longer than vertebrae. However, many of the fish species were bottom- dwelling species which would not normally be 100 SAN JUAN ISLANDS ^ OLYMPIC PENINSULA ED PUGET SOUND. Fic BIRDS FISH MAMMALS SHELLFISH URF I. Frequency of occurrence ol food items collected below nests and at perch trees of Bald Eagles in the San Juan Islands, Olympic Peninsula and Pugct Sound in western Washing- ton, 1980-1981. Numbers in parentheses are the percentages of each taxa that occur in each area. available to eagles. We suggest that these fish were discarded by sport or commercial fisherman who consider some species of bottom fish undesirable. Retfalvi (1970) found that Old World Rabbits were a common food item at two nests he studied on San Juan Island. He suggested that eagles scavenged rabbits killed b
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