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.
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.
A New Tool to Keep Track of Shifting Diets
“In a context of climate change, it becomes increasingly urgent to understand and be able to quantify killer whale diets and how they are changing so that we can foresee the potential impacts on local food webs,” says Anaïs Remili, a PhD candidate in the Department of Natural Resource Sciences at McGill University and the first author on a paper published in Journal of Animal Ecology. “By measuring the composition of the fatty acids of approximately 200 killer whales and of 900 of their prey of different species, we were able estimate the specific proportions of each prey species in the whales’ diets. This means that scientists can potentially keep track of any shifts in these diets in the future.”
Read more at McGill University
Image: The feeding habits of Orcas vary depending on location and individual. (Credit: Rune Dietz)
