A vast herd of northern caribou that scientists feared had vanished from the face of the Earth has been found, safe and sound -- pretty much where aboriginal elders said it would be all along.

"The Beverly herd has not disappeared," said John Nagy, lead author of a recently published study that has biologists across the North relieved.

Those scientists were shaken by a 2009 survey on the traditional calving grounds of the Beverly herd, which ranges over a huge swath of tundra from northern Saskatchewan to the Arctic coast. A herd that once numbered 276,000 animals seemed to have completely disappeared, the most dramatic and chilling example of a general decline in barren-ground caribou.

But Nagy's research -- and consultation with the communities that live with the animals -- concludes differently.

His work springs from recent studies that question the long-held theory that caribou always return to the same calving ground. It holds that different herds use different grounds, and that's what sets them apart.

"In the past, herds have been defined based on their calving grounds," said Nagy. "However, it's been shown that not all herds maintain fidelity to their calving grounds."

Herds are now defined by which animals hang out together, not by where they give birth.

"It's actually behaviour that structures these herds, not calving grounds."

It turns out that the Beverly herd has simply shifted its calving grounds north from the central barrens near Baker Lake, Nunavut, to the coastal regions around Queen Maud Gulf. Nagy's analysis of radio-tracking data showed caribou in the region once thought to belong to the Ahiak herd are, in fact, Beverly animals.

"It showed that there were two different subpopulations of caribou within that area that calved along the Queen Maud Gulf," he said. "One is migratory, which I believe is the Beverly herd."

The new theory hasn't been entirely accepted, but it's starting to convince wildlife regulators.

"We're leaning that way," said Ross Thompson of the Beverly-Qamanirjuaq Management Board.

Nunavut government biologist Mitch Campbell, one of Nagy's co-authors, said early results from a survey of the rediscovered herd suggest Beverly numbers are lower than their peak, but remain healthy.

"There's no indication that the herd is as large as it used to be," he said. "We did find a healthy size caribou population there.

"We saw lots of calves. The animals seem to be in good condition."

While scientists are excited, aboriginal elders are more likely to shrug.

Said Campbell: "When the initial alarm bells were ringing about the Beverly herd disappearing, right away we went in to talk to the communities and they said: 'No, no, no. These caribou have moved north and we've been told by our elders that they do that."'

Thompson heard -- the same.

"Many of the community people reported that elders think this is nothing new. Caribou move."

Next time, said Campbell, scientists should pay them a little more mind.

"We needed to engage the communities much sooner," he said. "The communities were the first to say this may not be an issue."

Still, he defends the previous science.

Long-term information on caribou was sketchy, but numbers did seem to be declining at the same time as mining exploration and development was expanding. Nobody wanted to be the biologist on whose watch the caribou disappeared, said Campbell.

"We were all freaking out," he said.

"We knew that there was development and things going on in that area. What would be the responsible thing to do -- just keep going until we know, or to say: 'Put the brakes on. We've got a problem?'

"That's what we all did."

Campbell and Thompson agree that the Beverly herd is likely to eventually return and that both calving grounds must be protected.

But for now, it's just good to know the caribou are still around, said Thompson.

"We haven't screwed up and lost a major caribou herd after all."