Alarmed by what it sees as a collapse of the mountain caribou herd, a local group is calling for a moratorium on logging in the upper Clearwater valley.

Yet a government wildlife manager questioned on Monday whether the southern Wells Gray herd is collapsing or simply in decline along with other B.C. herds.

The Wells Gray World Heritage Committee insists that the ministry's own population estimates show a marked decline in the southern herd. Very few caribou have been seen in southern Wells Gray in the past decade, said Trevor Goward, a committee member.

"I have it on authority … that the southern herd has collapsed," said Goward, a lichenologist who studies the lichen on which the caribou feed through winter. The population count is down by one-third, from 325 animals a decade ago to roughly 200 today.

"That's a collapse; that's as much as I need to know."

That population drop indicates that the provincial government's five-year-old mountain caribou recovery strategy isn't working, Goward said.

And he believes he knows why.

In 2004, a recovery implementation team focused on the Wells Gray area recommended that the strategy also ban logging in "matrix habitat" areas to ensure the recovery plan's viability.

Matrix habitat is comprised of lower-elevation areas not heavily used by caribou but frequented by their predators — wolf and cougars. When such areas, including those along the periphery of south Wells Gray, are clear-cut logged, moose and deer populations increase along with those of their predators.

Goward only just learned of the recommendation that went unheeded.

"Government must have known back in 2004 that by not including the matrix habitat and setting aside only winter habitat, it would make recovery impossible," he said. "It's habitat without which they can't survive."

The mountain caribou is recognized as a threatened species and the government is not living up to its responsibility under the Species At Risk Act, he said.

Chris Ritchie, one of the government's leading experts on mountain caribou, said the decision not to include the matrix habitat in the recovery strategy was broadly based.

"Like many of the decisions government makes, there are trade-offs to balance the management of environmental, social and economic needs," Ritchie said. "There's nothing particular to caribou about that."

The strategy does protect 95 per cent of the high-altitude winter habitat and includes a variety of protection measures, he said. At the same time, the government is assessing use of other management tools, such as wolf sterilization in the Williams Lake area and two pilot projects involving wolf and moose, to halt the caribou decline.

Ritchie admitted to being frustrated at the pace of that research, however, he's not convinced the southern Wells Gray herd is in a state of collapse. Aerial surveys in the past have grouped together the southern and northern herds, so it can be difficult to distinguish the accuracy of figures.

Will the other tools be able to arrest the decline?

"It's always dangerous to speculate," Ritchie said. "My frustration is that the other tools have not borne out yet. They may not be effective and we'll have to start to look at other measures."

Goward isn't sure that time is on the side of the southern herd. Matrix habitat is integral to population survival, he feels.

"Everything says this is the wrong way and the caribou won't survive unless something's done very quickly. To do otherwise is neglect at its very best."