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We examined stomach contents of northern pike (Esox lucius) to document their prey species during a fish sampling study in the eastern interior of Alaska in summer 2000. Sampling occurred in the Black River drainage near 66 ̊42.3' N, 144 ̊15.6' W. Most northern pike that were feeding had fish prey in their stomachs. But two northern pike captured on 11 June 2000 had recently consumed newly hatched chicks of the bald eagle (Haliaeetus leucocephalus), a species that to our knowledge has not been reported previously as prey of northern pike. Both bald eagle chicks were positioned head forward, and their posterior regions were partially digested. We estimated the chicks’ ages from their development as younger than five days. The northern pike predators were 71 and 77 cm fork length. We captured the fish within one km of each other, one in an oxbow lake and one in the Black River near the lake’s outlet. We assume that the chicks were from the same nest because of the proximity of the fish capture sites and the similar development of the chicks. We can only speculate on how the chicks ended up in the water; perhaps they fell out of their nest, or their nest fell into the water. In interior Alaska, bald eagle nests are usually located in large trees within 100 m of shorelines of water bodies (Ritchie and Ambrose, 1996; Steidl et al., 1997). Bald eagle nest trees that occur along large rivers or lakes can fall into water bodies when banks erode or when beavers (Castor canadensis) cut the trees. Northern pike are generally considered to be nonselective piscivores, eating primarily fish along with a small proportion of other vertebrate and invertebrate prey (McPhail and Lindsey, 1970). Raat (1988), in his extensive review of the biological data on northern pike, says that food selection of northern pike is thought to depend more on size, relative abundance, and vulnerability than on species preferences. Therefore, it should not be too surprising to find unusual prey species occasionally. For example, Solman (1945) found a yellow-headed blackbird (Xanthocephalus xanthocephalus) and Lagler (1956) found a garter snake (Thamnophis sirtalis) in their respective northern pike feeding studies. Neither of these species is common prey for northern pike. Similarly, bald eagle chicks are not a predictable or common food source for any animal, including northern pike (Buehler, 2000), but it is clear that northern pike will eat them on the rare occasions when they are available. Partially digested bald eagle chick inside the stomach of a northern pike.

New Prey Species Documented for Northern Pike <i>Esox lucius</i>): Bald Eagle (<i>Haliaeetus leucocephalus</i>)