Wolves living on the south-west coast of Alaska are increasingly eating sea otters. Other marine species also form a significant part of the animals鈥� diet, suggesting Alaskan wolves have a more flexible diet than previously thought.
Grey wolves (Canis lupus) typically eat large hoofed animals like deer, elk or moose, but they have been expanding their diet in recent years. Experts and locals already knew that wolves living along the coast occasionally picked off sea otters, but last year researchers reported for the first time that a small group of wolves living on an Alaskan island were eating mostly sea otters, and very few deer.
To see if other wolves have also expanded their diet, at Oregon State University and her colleagues turned to faecal sampling. They collected the scat of grey wolves living in seven different locations in the Katmai National Park and Preserve on the south coast of Alaska between June and September 2021. The team then sequenced the DNA found in 545 samples to find out what the wolves were eating.
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The DNA analysis revealed that they ate 67 different vertebrate species, most of which came from the sea. Sea otters were the most common prey species detected in the scat, present in 166 samples, or nearly one-third of the wolves鈥� droppings. Salmon came in second, detected in 28 per cent of samples, followed by other ocean fish species at 13 per cent.
鈥淲e also see they are eating marine mammals like seals and sea lions,鈥� says Dymit, and occasionally beached whales. The wolves ate land animals like beaver, moose and brown bears less commonly. Wolves from all seven sampling locations were eating sea otters, suggesting that they 鈥渁re extremely flexible and able to take advantage of shifting resources鈥�, says Dymit, who presented the findings at the in Portland, Oregon.
One reason wolves are turning to sea otters could be prey availability, as highly successful reintroductions have bolstered otter numbers in recent decades. It is possible that sea otters were a significant part of the wolves鈥� diet before hunting winnowed otter numbers, and that their recovery has restored a historical prey source for coastal grey wolves.
In most cases, the wolves stalk and hunt the otters and other marine species in tide pools or shallow water before dragging them onto shore to eat.
