Wolves are thought to be one of the most all-around important (non-human) predator of beavers in both North America and Eurasia, but catching them in the act of hunting these oversized semi-aquatic rodents – let alone on camera – is rare.
The past year or so, however, has turned up some impressive footage on that front out of the US state of Minnesota, a hotspot for research into the wolf/beaver dynamic. And the latest video is perhaps the most impressive yet.
It was taken this past fall by a deer hunter, Jon Galler, near Hill City, Minnesota, and shared by the Voyageurs Wolf Project, which researches the boreal wolves of the Greater Voyageurs Ecosystem farther north in the state.
In its post, the Voyageurs Wolf Project shared some insights into the event gleaned from Galler. He’d been watching the beaver – thought to be a kit on the order of six or seven months old – for about a quarter of an hour before the wolves showed up and crossed the nearby beaver dam. The beaver had been grooming itself on a rock in the shallows of the beaver pond, and both wolves and rodent appeared unaware of one another until the lead wolf finished a bout of scent-marking. Its scraping spooked the beaver, which plopped into the water, thus alerting the wolf.
“The wolf heard the beaver slip into the water and immediately changed its behaviour,” the post explains. “You can see this clearly in the video. The wolf then bounded into the pond and caught the beaver, which was entirely below the water.”
A 2016 study in Voyageurs National Park found evidence of wolves dragging beavers out of their feeding canals and other waterways to dispatch them onshore, based on analysis of kill sites. The Voyageurs Wolf Project notes that Galler’s video, however, appears to be the first direct observation of a wolf successfully catching a beaver that’s swimming fully underwater.
In most of the northerly realms where wolves and beavers co-occur, the rodents are most exposed to predation during the ice-free seasons, as their wintertime goings-on in frozen-over waterbodies and lodges keep them mostly out of the reach of wolves. From spring through fall, beavers in such forestlands are more at risk on account of open water and the need to forage onshore and conduct upkeep on lodges.
This also overlaps with the time of year when wolves often prowl alone or in small groups as opposed to hunting as a full pack, as is typical in winter, when mature deer and other ungulates anchor the boreal wolf diet. Beavers, as well as newborn ungulates and other smaller animals, are prized summer prey for wolves hunting solo or in pairs; growing beaver kits that are out and about on their own (as this unfortunate little guy in Minnesota was) in summer and fall are particularly vulnerable.
The predation in this case was apparently opportunistic: The wolf suddenly noticed the young beaver and literally sprang into action. It’s possible, of course, that these wolves were intentionally traveling along the beaver dam and pond to search for beavers. But research out of the Greater Voyageurs Ecosystem has shown that wolves there deploy a number of specialised hunting tactics to specifically target beavers, among them lying in wait beside waterways or feeding trails to snag the paddle-tailed critters as they come ashore or commute on land. Such ambush attempts may see wolves crouched for hours at a time – a far cry from the cursorial (running) pursuit after fleet-footed game with which these wild canids are most associated.
A study from last year suggested the threat of wolf ambush may limit how far beavers forage from the (relative) safety of water, and could conceivably therefore impact the spatial event of beaver-gnawed forest in boreal ecosystems. A decades-old paper found that beavers preyed on by black bears on Stockton Island – part of the Apostle Islands off northern Wisconsin’s Lake Superior shore – foraged closer to water than their counterparts on nearby, and bear-less, Outer Island.
While a beaver might not be as intimidating a prey item as a swift deer or a giant ornery moose, don’t suppose it’s a pushover. After all, North American and Eurasian beavers are the second-biggest rodents on Earth after the capybara of South America – they may tip the scales beyond 27 kilograms (60 pounds) – and those tree-felling chompers of theirs can pack a punch. As the Voyageurs Wolf Project notes in its post about Miller’s video, the wolf’s capture would likely have been a bit tougher had the beaver in question been full-grown. Indeed, one Twitter user commented on the post: “As a boy in the 1960s I met a hunter who had observed an adult beaver killing a wolf, in defence, by dragging it into the pond and drowning it.”
Wolves and American black bears, meanwhile, aren’t the only carnivores with a taste for beaver meat. Others documented to actively prey on beavers include wolverines, red foxes (which sometimes snag small kits), and pumas. One puma in western Colorado even appeared to become a beaver specialist. And a few years ago, a livecam caught an Alaskan brown bear that was fishing in Katmai National Park & Preserve happily snatch a beaver that just about cruised right into its lap:
Top header image: Yellowstone National Park/Flickr
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