Mitch Seavey, a three-time Iditarod champion, said he carries two guns – a .44 Magnum and .357 Magnum – during the annual dog sledding race in Alaska.

That way, Seavey says, he’s ready for the moose.

On Monday, his son Dallas, a five-time Iditarod champion, shot and killed a moose in self-defense after it became entangled with his dogs about 70 miles from the start of the race, officials said Monday. What officials did not say is why a moose, the state animal in Alaska that is typically calm, would pose a threat to mushers and their sled dogs.

A good place to start is with Jacob Pelham, a wildlife biologist with the Alaska Department of Fish and Game.

"Moose tend to get grumpy late- to mid-winter," Pelham told USA TODAY Sports. "It’s been cold out. A lot of their food is covered up (by snow).

"They’re basically digesting the dormant branches of willow and birch and aspen. So if you imagine you have a big snow come into an area with a bunch of willow and birch and all of the sudden three-quarters of the plants are covered up."

Less food but no fewer moose. According to Pelham, that leads the animals to be more aggressive – as some mushers learn in frightening fashion during the 1,000-mile race.

Mitch Seavey, 57, said three or four mushers have shot and killed moose in self-defense during the Iditarod over the four decades he has competed in the race.

Why else might a moose attack?

The food shortage is only one factor, said John Crouse of the Kenai Moose Research Center in Alaska.

He said large snowfall, such as what Alaska has experienced this year, leads the moose to look for an easier path to travel. Favored paths include snow-packed trails on the Iditarod course.

"They’re generally very calm and not aggressive animals," Crouse said of moose. "But when they’re in situations where you get up close and they don’t have an easy exit, they can be very cantankerous.

"You come around a corner with 16 dogs and a sled and surprise an animal and they’re apt to get pretty aggressive."

Mitch Seavey and other mushers told USA TODAY Sports they think the moose attack because they mistake the dogs for wolves, which prey on moose. But the Alaska Department of Fish and Game reports only, "Moose view dogs as enemies and will sometimes go out of their way to kick at one, even if the dog is on a leash or in a fenced yard."

In the absence of deep snow, moose on the Iditarod trail usually took flight, according to retired musher Aliy Zirkle, who said she carried a flare gun in case of a moose confrontation.

"You could at its feet, the flare would go off and theoretically it would run away," she said. "Now if that didn’t work, and you had no flare left, you’d kind of be out of luck."

How dangerous are moose?

Almost 30% of fatal bear attacks are recorded in Alaska and that includes at least 14 deaths since 2000, according to The Alaska Frontier. But more people are injured by moose, by a 3-to-1 margin, according to Wildlife X Team.

Moose, which typically weigh at least 1,000 pounds and stand higher than six feet at the shoulders, can inflict serious damage to sled dogs. Four dogs were seriously injured and one later died during a moose attack in 2022 when Bridgette Watkins was training for the Iditarod.

"That moose had a look in his eye," Watkins wrote in a story for Alaska Public Media. "He just wanted death to occur. Like he just wanted to kill us."

Fatal moose attacks are rare. But in 1995, on the campus of the University of Alaska, a moose trampled a 71-year-old man to death.

What happens after a moose is killed?

Race rules state a musher can kill a large game animal if it’s done in defense of life or property, as race officials say Dallas Seavey reported it happened. But he could not promptly resume racing after the incident.

Race rules required he first gut the animal. The meat is salvaged whenever possible and goes to a charity, according to Pelham.

"If you leave the guts in an animal that’s been shot that you’re wanting to consume, acids start to break down," Pelham said. "It can cause an ill effect on the meat.

"Our agency, we do our best to maintain a healthy moose population. And the moose that do get killed, we try to make sure that it’s ethically and responsibly harvested and as much respect is shown to that animal as possible."

Not that such protocol will leave everyone satisfied, according to Pelham.

"I’m sure you’ve read about people who are protesting the Iditarod itself," he said, referring in part to the People for the Ethical Treatment of Animals (PETA). "So I’m sure there’s somebody out there that’s upset with what’s happened.

"It is unfortunate. I’m sure the musher did not want that to happen. Not just because that set him back in the race, but we are all moose lovers here in Alaska."