The nominal star of The Grey, America’s top-grossing film, is Liam Neeson. The real stars are the hungry wolves that pursue him and his fellow plane-crash survivors through Alaska’s pristine wilderness. The CGI-enhanced wolves are big, smart, and scary.

But is their behavior based in reality? To parse wolf fact from fiction, we caught up with Daniel MacNulty, a wildlife-ecology professor at Utah State University whose research on Arctic wolves is funded in part by the National Geographic Society.

First off, would wolves see men as prey and stalk them in the wild? I’d think that in a remote area like this one, wolves might fear or avoid humans.

In my 16 years of studying wolves in Yellowstone National Park, I have never been approached by a wolf or wolf pack. On the contrary, when I’ve inadvertently bumped into wolves they turn and run away—which is a problem when my objective is to observe them!

One of the characters in the movie says these wolves a) have a 300-mile hunting radius, b) will attack anything that comes near their den, and c) “are the only animal that will seek revenge.” Is any of that that true?

No. Nonsense, all of it.

Would a wolf attack a man standing next to a fire, with other men nearby, as happens in The Grey?

Not a chance.

At one point two men are running alongside a riverbank in the middle of the day. Two wolves race out of the trees and charge them. Possible?

No.

Some of the wolves in the movie are huge—not Twilight size, but larger than I’d expect. How big can a gray wolf get?

In Yellowstone, the average weight of adult male wolves ranges between 100 and 120 pounds. The average weight of adult female wolves ranges between 84 and 93 pounds.

Do wolf eyes really glow in the dark, as they do in this movie?

The eyes of wolves and many other wildlife appear to “glow in the dark” because of a layer of tissue in the eye called the tapetum lucidum. It reflects visible light back through the retina, which improves vision in low-light conditions. So when light shines into the eye of an animal [with] a tapetum lucidum, the pupil appears to glow.

The cooperative hunting nature of the pack is played up a lot in this film. Is that accurate?

The extent to which wolves cooperate while hunting in a pack is greatly exaggerated. In a recent study, I showed that wolves are often freeloaders. That is, most wolves keep up with a hunt simply to be on hand when a kill is made. Imagine tackling a moose or bison with only your teeth, and you can start to appreciate the incentive a wolf has to hold back during a group hunt.

Speaking of cooperation, in one scene a lone wolf enters the men’s nighttime camp. The protagonist says it’s an omega wolf “sent in” by the alpha wolf to test the humans’ defenses. Does anything like that ever happen with wolf packs?

No. This is pure fiction.

At the end of the movie, the hero finds himself in the wolves’ den. It’s littered with bones and carcasses. Is that a realistic depiction?

In the dens I’ve examined, most of the bones and carcass remains are on the outside of the den rather than in the inside.

In the final scene, the protagonist prepares to fight the alpha wolf. He tapes broken mini liquor bottles to his hands. Would that give him a chance against a large male gray wolf?

If I was lucky enough to encounter a large male gray wolf in the wild, he would turn and run before I could tape the first bottle to my hand. Most people don’t realize this, but wolves are wimps.



