Another caribou herd in British Columbia is on the edge of dying out and conservation groups are calling for more protections for the animals.

The South Purcell herd, which ranges north of Kimberley, is down to four animals.

Biologists flew over the herd last week and counted just three bulls and a cow.

"We don't know if it's predation, avalanche," said provincial biologist Leo DeGroot. "A large group could be wiped out in an avalanche."

Conservation groups don't know either — but they are suspicious as a second Kootenay herd approaches local extinction in one year.

Mere weeks ago, it was discovered the South Selkirk herd is down to three caribou.

Caribou terrain is supposed to be closed to snowmobilers, but Candace Batycki with the Yellowstone to Yukon Conservation Initiative questions whether that is being followed.

"When it was one herd losing two thirds of its animals, we thought it's an avalanche," Batycki said.

"Now that it's two herds, it's looking fishy.

The B.C. Snowmobile Federation says now is not the time for pointing fingers.

The federation says 80 per cent of caribou habitat is off limits to sledders and almost all snowmobilers stick to that.

Provincial biologists don't know what they are going to do about the two disappearing herds.

Batycki says the animals' disappearance should tell us something.

"That our ecosystems are unravelling. Our landscapes are nearing the point where they are unable to support wildlife," she said. "Humans are unwilling to constrain their own activities and coexist with wildlife."

Batycki says B.C. needs an investigation into what's happening to the caribou and better enforcement of backcountry closures.

With files from Bob Keating