First records of False Killer Whales, Pseudorca crassidens, in Canada

Abstract

A stranding of an adult male False Killer Whale (Pseudorca crassidens) on Denman Island, British Columbia, on 3 May 1987, was the first record for Canada. Stomach content analysis revealed small numbers of parasites (Anisakis sp.) and recent predation on salmon (Oncorhynchus sp.) and squid (either Berryteuthis magister or Gonatopsis borealis). Osteological evidence and tooth dentine-layer counts (26 growth layer groups) indicated an individual of advanced age. Tissue analysis for heavy metals and pesticides revealed very high levels of mercury (liver, 728 ppm wet weight) and DDE (blubber, 1400 ppm wet weight). A group of at least 12 other P. crassidens remained in the inshore waters of Puget Sound, Washington from 3 May 1987 to 2 July 1987, one of which stranded and died. A single individual P. crassidens was photographed in Johnstone Strait, B.C., on 22 June 1987, and a different individual P. crassidens live-stranded in Ucluelet, B.C., on 28 July 1987, and was returned to the water.