A man who was attacked and killed by a bear in a remote forest in Wyoming is a reminder to always be prepared around the formidable predators, an expert says.

Government officials confirmed this week that Adam Stewart, a research contractor for the U.S. Forest Service, was mauled by a bear. His remains were found last week in Bridger-Teton National Forest.

Stewart died from blunt force trauma to the head resulting from a bear bite, although it's unknown whether a grizzly bear or a black bear is to blame.

There are two types of bear attacks: defensive and predatory, says John Beecham, co-chair of the Human-Bear Conflicts Expert Team of the International Union for Conservation of Nature's Bear Specialist Group.

"It sounds like this was a bear defending a food source—a type of attack that's quite common," says Beecham, citing news reports.

We talked to Beecham about why bears attack and about how to avoid that danger.

What was your reaction to the mauling?

I don't know how well [Adam Stewart] was trained for doing this work; all I can say is there are ways to avoid these kind of encounters and that didn't happen.

[For instance,] if I were going to be in an area that has a lot of grizzlies and black bears, number one, I wouldn't go alone, and number two, I would be carrying bear spray with me.

If I was going into an area with limited visibility, which sounds like was the case, I would be making a lot of noise to alert the bear that I was there and give it an opportunity to sneak away.

View Images Volunteers do trail work in July in Wyoming's Bridger-Teton National Forest, where the bear attack occurred. Photograph by Dina Rudick, The Boston Globe, Getty Images

Was the attack most likely by a grizzly or a black bear?

It would be an extremely unlikely event for a black bear to attack with that kind of aggressiveness in defense of a carcass. (Also see "Canada Mauling Reflects Spike in Human-Bear Encounters.")

What might this bear have been thinking?

Bears treat people more or less like other bears. Where you have high densities of bears, like along the salmon streams in Alaska, bears are tolerant of other bears, and lo and behold they're also tolerant of people in those situations.

But when you get in a situation with low density of bears like in ... the lower 48 [states], they're far more aggressive toward people and other bears. The bear was possessive of that carcass, and it probably just viewed this guy as someone that [wanted to take] the carcass.

How common is this type of attack?

It's extremely rare—you're far more apt to die from a bee sting or falling and hitting your head than a grizzly bear attack. That's particularly true if you're well educated on how to behave in bear country.

I've known hundreds of biologists who live with bears in the field, and the majority have never had a close call. They know how to behave and take the precautions they need to to prevent that kind of situation. (See "'Bear Man' Lynn Rogers on Recent Attacks: Don't Fear Bears [2013].")

View Images LAUREN E. JAMES AND KELSEY NOWAKOWSKI, NG STAFF; MEG ROOSEVELT. SOURCE: IUCN; HERRERO, S., ET AL. Journal of Wildlife Management; HANK HRISTIENKO, MANITOBA CONSERVATION AND WATER STEWARDSHIP

Are grizzlies and black bears rebounding in population in Wyoming and other parts of the West?

Absolutely. Grizzly bears were listed as a threatened species in 1975, so there's been a lot of protections afforded them since that time. They've been able to reduce human-caused mortality [for example, getting struck by vehicles]. The primary source of mortality is humans.

In the late 1970s the population in Yellowstone was at 200 to 250 bears. Now [it's] well over 600. There's a proposal to delist them [in Yellowstone] because the population is doing so well. They'll continue to do well as long as we keep a handle on human-caused mortality.

Does this kind of attack influence the decision to take grizzlies off the endangered species list?

No. This would not have any effect whatsoever. The conclusion [wildlife managers] will come to—and this won't be the first time—is this was a natural behavior.

As I said, bears are known to protect their young, protect themselves, and protect their food supplies. If a bear is involved in [an attack based on] one of those three situations, the management authority won't take any action because it's a natural behavior.

If a bear enters a building or a camp, however, it's not considered natural and [managers] will take action. (See National Geographic's bear videos.)

Any other takeaways from this incident?

The most important thing that people don't realize is there's a lot of information out there about how to behave in areas where you find grizzly bears.

There have been a number of studies that show bear spray is very effective at deterring attacks, and [visitors to bear country] should be carrying that with them—not in their backpack but in their hand. [If you see a bear at] 30 yards, you're talking tenths of a second before the bear would be on you.

What should you do when a bear attacks?

If you fail to prevent an attack and the bear comes at you, the best survival strategy to to play dead—reduce the threat that the bear perceives you to be. If the attack is a predatory attack, then your only option is to fight back; needless to say, it will likely be unsuccessful if you are alone.

Defensive attacks typically occur without warning, while predatory attacks often involve the bear approaching you in a cautious manner trying to assess the threat you might pose if it does attack. Again, it is testing you as it would another bear.

Even so, [getting attacked by a bear is] an extremely rare event—it's not something you need to be fearful of when you're in the woods.

This interview has been edited and condensed.