Feeding ecology of long-finned pilot whales Globicephala melas in the western North Atlantic

Stomach contents from 30 long-finned pilot whales Globicephala melas captured incidentally in the Distant Water Fleet (DWF) mackerel fishery off the northeastern United States were examined. Several methods of assessing prey importance were used in order to construct a true representation of the pilot whale diet. Separate analyses of trace (free, durable body parts from well-digested prey) and non-trace (relatively intact prey) food materials were conducted to address biases caused by differential rates of digestion and passage. Squids dominated the diet and long-finned squid Loligo pealei was the most important prey, but we noted large yearly fluctuations in prey importance. Metric multidimensional scaling analyses of trace and non-trace stomach contents of individual whales suggest that many animals were caught while feeding opportunistically near fishing operations, resulting in a bias of non-trace (intact) stomach contents. The diversity of prey in this study was greater than previous reports of the food habits of western North Atlantic long-finned pilot whales.

Duke Scholars

Author Andrew J Read Marine Science and Conservation