--While conducting an offshore bird census
from the sea beach at Nelson Lagoon, Alaska Peninsula (56ø00'N, 161ø10'W) at 1700 on 17 September
1976 1 saw a Fork-tailed Storm Petrel (Oceanodromaf. furcata) feeding on the beached remains of an adult
gray whale (Eschrichtius robustus) that had been trapped by ice and died the previous April. I watched it
for about 15 min. The sky was overcast with a 25-knot offshore wind, gusting to 35 knots. Seas were
running from 3 to 4 m, and the tide was high. This observation is of note because it provides direct
evidence of a terrestrial (i.e. nonpelagic) foraging capability by O. furcata. It also furthers the scant
knowledge on the use of beached marine mammals for food by pelagic and inshore avifauna, especially
during adverse weather when normal foraging habits might be inhibited.
This particular bird, which was subsequently collected (USFWS-OBS-056, imm. female), was feeding
in association with approximately 40 adult and hatching-year Glaucous-winged Gulls (Larus glaucescens)
and three adult Sabine's Gulls (Xema sabini). The petrel actively fed among the gulls by hovering over the
beach and then picking up small pieces of whale tissue being torn loose by wave action and washed up on
the beach. Three times the bird landed on the beach and picked up what appeared to be food items cast
high on the tide line. Subsequent examination of the stomach contents revealed approximately eight small
pieces of whale fat, feathers, the lens of a fish or squid eye, and five pieces of smoothly worn pumice. The
latter could have been picked up floating at sea or on the beach. Twice after successfully obtaining items
the petrel alighted on the back of the whale within 1 m of several gulls also sitting on the carcass. No
interspecific reactions were observed among the birds.
Fork-tailed Petrels are frequently seen in intertidal waters along the Alaska Peninsula in fall and early
winter, usually during or following storms. Two others were seen within Nelson Lagoon, approximately 1
km from the open coast, 2 weeks after this incident (Anthony DeGange pers. comm.). Robert D. Jones
(pers. comm.) reported seeing several hundred fork-tails each year (1963-1975) over Izembek Lagoon
(55ø20'N, 161ø00'W) in October and November.
The fact that O. furcata, and storm petrels in general, occasionally feed on the oil and other remains of
dead marine mammals and other offal while at sea has been reported by several authors (e.g. Palmer 1962,
Handbook of North American birds, New Haven, Yale Univ. Press, and Dement've et al. 1952, Birds of
the Soviet Union, vol. 2), but I found no references in the literature to direct evidence of terrestrial
foraging by O. furcata or other hydrobatids. Palmer (op. cit. 234, 250.) reports small stones or cinders in
stomachs of adult and young petrels taken while on the nesting grounds, while Bianchi (in Dement've op.
cit., 334) found pieces of sorrel (Rumex spp.) in stomachs of O. l. leucorrhoa also taken on the nesting
grounds. More recently, our laboratory has found Carex and Eleocharis seeds in O. furcata stomachs
collected from the Gulf of Alaska. Both of these seeds are buoyant and were probably picked up at sea.
This investigation was part of the Outer Continental Shelf Environmental Assessment Program funded
by the Bureau of Land Management through the National Oceanic and Atmospheric Administration. I
thank Gerry Sanger, Jim Bartonek, and Pat Gould for suggestions on improving this note.--ROBERT GILL
JR., U.S. Fish and Wildlife Service, Office of Biological Services, Anchorage, Alaska 99501. Accepted
15 Dec. 76. (This paper was subsidized by the author.)