Tastes Differ -- even among North Atlantic Killer Whales
Published:06 Jun.2023    Source:McGill University

Killer whales (also known as orcas) are intelligent predators. While it's known that killer whales in the Pacific Northwest exploit widely different food types, even within the same region, we know much less about the feeding habits of those found throughout the North Atlantic. Thanks to a new technique developed by a research team led by McGill University, it is now possible to quantify, for the first time, the proportion of different prey that killer whales in the North Atlantic are eating by studying the fatty acid patterns in their blubber.

In the largest study of its kind, this approach was used to look more closely at the diets of killer whale from the eastern and northern coasts of Canada all the way to northern Norway. It provides the most detailed overview of North Atlantic killer whales diets to date. As climate change leads to a northward redistribution of killer whales, the results have implications not only for the health and survival of these killer whales, but also in terms of potential impacts on sensitive species within Arctic ecosystems.
The team found that killer whales have very different diets throughout the North Atlantic. Killer whales feed predominantly on fish, especially herring in the Eastern North Atlantic (Norway, Faroe Islands, Iceland), and in the Central North Atlantic (Greenland) they primarily eat seals.In some areas, killer whales prefer to consume other whales: belugas and narwhals in the Eastern Canadian Arctic and baleen whales and porpoises in Eastern Canada.