Two young men who allegedly murdered three people before disappearing into the vast Canadian wilderness could survive in the elements “for weeks,” according to a survival expert familiar with the terrain of northern Manitoba.

Dave MacDonald, who runs the International Canadian School of Survival and served 19 years as a search and rescue technician with the Royal Canadian Air Force, told Fox News on Wednesday that the chance of survival for fugitives Kam McLeod and Bryer Schmegelsky depended on one condition — their will to stay alive.

“Even if they had next to no gear, they could go a very long time if they have the will to survive,” MacDonald said.

Security camera images of Kam McLeod, 19, and Bryer Schmegelsky, 18. (The Canadian Press via AP)

“With, let’s say, mediocre training, they could last until late fall -- until the temperatures start to drop and then they need to seek shelter,” he said.

MacDonald said there's “an abundance of food” for McLeod and Schmegelsky if the men — who grew up in the wilderness of Port Alberni, British Columbia — know how to search for it.

“If they know anything about food and wild animals, there’s a lot of food out there — berries, fish, grouse, frogs and insects,” he said.

McLeod, 19, and Schmegelsky, 18, have eluded capture for nine days in the wilderness of northern Manitoba. The two have been charged in the death of Vancouver professor Leonard Dyck and suspected in the double homicide of Australian Lucas Fowler and his American girlfriend, Chynna Deese. Witnesses reported seeing the men in Dease Lake, B.C., Cold Lake, Alta., Meadow Lake, Sask., and Gillam, where the trail went cold.

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MacDonald, who is not part of the search efforts in this case, noted the many challenges the suspects likely were facing, including bears, dehydration, drowning or injury and navigation.

“Bears could be an issue especially if they're not sanitizing their hands or face after eating food like fish, or if one of them is bleeding,” said MacDonald. “And then, there are the high bluffs, where it’s not hard to twist an ankle.”

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“You've got waterways to cross all the time,” he said. “The rivers up there -- most of them are wild and majestic and they've got some speed and volume to them. It wouldn’t take much if you’re weak to get swept up in one.”

“They'd have to follow a line of communication, like railroad tracks or a waterway. Otherwise, how do you navigate in the middle of nowhere?” he said. “And then, you’re trying to do it all in stealth mode -- not easy.”