Aves Specta

Eric M. Larsen and Scott A. Richardson. 1990. Northwestern Naturalist 71:88-92.

Abstract

Shorebirds wintering at Grays Harbor, Washington, were oiled when No. 6 fuel oil spilled from the barge Nestucca on 22 December 1988. Counts and observations on eight days during the ensuing two months provided information on the effects of oiling on black-bellied plover (Pluvialis squatarola), semipalmated plover (Charadrius semipalmatus), sanderling (Calidris alba), western sandpiper (C. mauri), and dunlin (C. alpina). Initially, 31% of shorebirds we observed roosting on ocean beaches were oiled; 10 days later this dropped to 5%. A harbor rate of 34% oiled shorebirds occurred after the ocean beach rate declined, then percentages of oiled shorebirds at each locality declined to insignificance. We report on behavioral changes observed in oiled dunlins and discuss three alternate hypotheses to explain the disappearance of over 3500 oiled shorebirds: self-cleaning, emigration, and mortality.

Published by the Society for Northwestern Vertebrate Biology