Diet of wintering Bald Eagles, Haliaeetus leucocephalus, in New Brunswick

The diet of wintering Bald Eagles (Haliaeetus leucocephalus) in New Brunswick was determined from 949 feeding observations, 1992-1999. White-tailed Deer (Odocoileus virginianus) accounted for 43% of the total occurrences, offal 30%, birds 16%, other mammals 8%, fish 3% and invertebrates < 1%. Thirty-five percent of the prey items were of aquatic origin. There were considerable dietary differences between inland and coastal feeding eagles. Avian prey (seabirds and waterfowl) were of greater importance to the coastal birds. Salmon offal consumption at aquaculture sites along the coast was significant. Over 70% of the dietary items taken by immature eagles were scavenged deer and offal. Some of the prey items consumed showed a marked seasonal variation. Almost 60% of all feeding occurrences in February and March involved deer. Both birds and fish decreased in importance from late fall to early spring. Immature eagles were found more commonly in mixed feeding groups than as solitary foragers. The risk of environmental contaminant exposure is Likely greater for coastal wintering eagles that feed more heavily on aquatic organisms than for inland wintering birds.