Grizzly Bear vs Junction Butte Wolf Pack

One of the world’s most watched wolf packs went head-to-head with an aggressive grizzly bear in Yellowstone National Park in late December 2019. The famed Junction Butte wolf pack fought to protect an elk carcass from being mauled while Daniel Bradford of BrushBuck Wildlife Tour recorded footage of the encounter from the park’s northeast entrance.

The video depicts an iconic scene that brings to mind an old dusty painting hanging in a western bar. The roaring grizzly bares its teeth as it is surrounded by at least twelve wolves who relentlessly surround the deer carcass. When one of the wolves makes a bold move to retrieve what’s left of the deer, the big bruin lunges forward and lunges at the dog with one of its massive front paws. Meanwhile, the main girder and two fork rings of the deer can be seen sticking out of the snow as bows and ravens dart in and out of the frame looking for discarded scraps. Check it out for yourself below.

The video describes a relatively common phenomenon

“Grizzlies are really good at scavenging and usurping kills,” says wolf expert and Game and Fish Department of Big Fish supervisor Dan Thompson. “We see that a lot with the hunter harvest. They sometimes get a carcass before a hunter can get to it.”

In the type of scenario described by Thompson, most human hunters will leave the deer to the encroaching grizzly. But the wolves are not so quick to leave. In fact, a recent study conducted in Yellowstone over several seasons found that the presence of a grizzly bear at a wolf pack kill site tends to increase the amount of time wolves will ultimately spend there.

According to the study, wolves spent up to six extra hours on carcasses when grizzly bears were cleaning up their kills. This type of “interference competition” between top predators can alter their top-down impacts across ecosystems. For example, when a wolf pack spends more time avoiding a scavenging grizzly kill, they spend less time hunting and killing other members of the area’s ungulate packs.

The study authors went on to say that the more evenly matched competing predators are, the longer they will interact at the site of a kill. “While brown bears are often able to dominate carcasses, the outcome of wolf-bear interactions varies based on the demographics and number of wolves involved,” the authors explain. “Our results suggest that interactions at kill sites between closest competitors are prolonged rather than shortened, perhaps because the potential for reward is greater.”

The battle took place over an unlikely part of the year

Grizzly planting and three cubs with two wolves on carcass at Alum Creek;
A doe confronted two wolves in Yellowstone in July 2010 — a much more common time for such interactions. Jim Peaco / NPS

The wolf vs. grizzly match recorded by Bradford took place in December. According to Thompson, simply witnessing an active grizzly bear deep into a Yellowstone winter is a rare occurrence. “It’s too late in the year,” he says. “We have some of those hogs that will stay out and try to find food later, but for the most part, most of the bears have been sleeping for at least a month.”

Grizzly bear activity during the winter may be indicative of a broader trend emerging across the Wyoming landscape. “We’re seeing more bear activity later and earlier,” he says. “If there’s a food source, they’ll stay out. They evolved to sleep for part of the year because there was less food available.”

As the numbers of wolves and grizzlies in Wyoming continue to grow, Thompson and his colleagues are seeing changes in the way all large predators behave and interact, not just wolves and coyotes. “We have carnivore population growth and we’re starting to see things change, maybe back to how they’ve been historically,” he says. “We have areas where wolves have moved and now there are fewer mountain lions. We see a lot of dynamics between black bears and grizzly bears, where black bears are moving into different diurnal activity patterns, where they are more active during the day than at night. It’s interesting to watch.”

Read further: The gray wolf falls on a large grizzly bear

As for the outcome of this particular conflict, the wolves eventually moved on, leaving the great bear alone with their kill.

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