For seven decades, the sole rulers of Yellowstone were grizzly bears. They are now re-learning how to cope with the rise of an equal competitor – the reintroduced gray wolf.
Some of the most fascinating things observed during the Yellowstone wolf reintroduction program involve the interaction between wolves and grizzly bears, said Doug Smith, the Yellowstone Wolf Project's leader.
More grizzly bears are showing up near wolf dens, and grizzly bears are taking away more wolf kills.
Smith says grizzlies are often attracted to wolf dens because of the "stank aroma" existing from the leg bones and other food items the alphas bring back to feed to their young.
The grizzlies are more powerful, but the wolves are quicker and out-number the bear," says Smith. "It's always interesting to see the interaction between the two carnivores.
"It's almost like the wolves are the mosquitoes buzzing around the bear's head. Although individual mosquitoes can't overpower you, if there are enough of them, they'll win. That's sometimes what happens with grizzlies and wolves. The bear gets near the den, and wolves just annoy the heck out of him.
"The wolves in Yellowstone won't give up. They just constantly orbit around the bear. I've actually seen one wolf bite a bear in the butt when he turned around," says Smith.
But around wolf kills, it's another story. In these cases, the grizzly is almost always the victor.
One time Smith watched as one bear held 24 wolves at bay at a carcass. The wolves had taken down a bull elk, but the bear took over the meal. Another time, he says there were 10 wolves and four bears on a wolf kill. The biggest bear controlled the situation. All of the wolves and the three other bears "sat around and waited for their turn."
Without a doubt, Smith says Yellowstone's grizzlies are benefiting from the wolves' presence due to their ability to successfully usurp the large canid's meals.
There has been some opposition to the wolf reintroduction program by ranchers and other groups, but for the most part, the program has been successful without bothering the bears.