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The secret lives of wolves: They fish and eat berries

Dec 17, 2018 11:15AM ● By Editor
New research at Voyageurs National Park is challenging the conventional wisdom on wolves: Their diets are a lot more varied than previously thought. Photo courtesy of Voyageurs Wolf Project.

By Dan Kraker of Minnesota Public Radio News - December 17, 2018

Wolves, as it turns out, might not be the bloodthirsty, moose-slaughtering, northwoods-roaming carnivores you always thought they were.

New research on wolf packs at Voyageurs National Park is challenging the conventional wisdom on wolves: Their diets are a lot more varied than scientists previously thought. 

Researchers with the Voyageurs Wolf Project, a collaboration between the park and the University of Minnesota, have for the first time documented wolves hunting freshwater fish as a seasonal food source — and they have video to prove it. 

A diet of meats and berries

Earlier studies on wolves in the park have shown that they eat a large number of beaver — and even blueberries — to supplement their diet, which still relies heavily on deer. 

These new discoveries, which were recently published in the journal Mammalian Biology, were possible thanks to new technology. 

Since 2015, researchers have been placing GPS collars on wolves from seven different packs in and around the park. They collect location data from the animals every 20 minutes, which allows them to zoom in on the animals' predation habits at a finer scale than earlier versions of the collars had permitted: When wolves spend more than 20 minutes at any one site, they know they're probably eating something. 

That's how they first suspected members of the Bowman Bay pack were eating fish. In April 2017, University of Minnesota researcher Tom Gable hiked to a creek where one of the collared wolves had spent a lot of time. He was searching for evidence of a kill. 

He looked up, and saw a collared wolf about 50 feet away. But the wolf didn't see him.

"It was really crazy," he said. "He came within about 8 to 10 meters of me and he had no idea I was there. I was hiding in the shrubs on the edge of this creek." 

Austin Homkes left draws blood from a wolfs leg
Austin Homkes, left, draws blood from a wolf's leg while Tom Gable assists. Photo courtesy of Tom Gable

For the next 15 minutes or so, Gable watched the wolf meander back and forth around the creek. Periodically it would run into the creek and splash around. Then it stopped, and looked like it was eating something, before returning to the creek. 

Eventually the wolf left, and Gable came out of hiding to explore the area. He realized right away the wolf was hunting fish — spawning suckers — in the creek. 

"And then as I explored the area even more, I found wolf tracks all over the mud on the creek, and I found fish scales and blood and guts all over the edges of the creek, and you could just see that wolves had been spending a lot of time there," he said. "And there were wolf scats as well that were full of fish scales and fish remains."

Gable and his colleagues quickly learned that little scene he witnessed wasn't just a one-time meal. In the month after his hike to the creek, researchers found the two GPS-collared wolves in the Bowman Bay pack spent about half their time hunting fish there.

To read much more on this story and read related articles, follow this link to the Minnesota Public Radio News website.

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