Buying time for our mountain caribou one cow and calf at a time

Some people think the dwindling herds of mountain caribou are doomed to extirpation, but a small band of biologists think they can reinvigorate the ungulates’ populations. Photo courtesy of the Revelstoke Caribou Rearing in the Wild Project

By David F. Rooney

Some people think the dwindling herds of mountain caribou are doomed to extirpation, but a small band of biologists think they can reinvigorate the ungulates’ populations.

They want to capture pregnant cows in the very early spring and keep them safe from predators in a heavily monitored and fences area until months after their new-born calves are judged healthy and hard enough to survive in the wild. Some of the young animals may still prey to bears, wolves, cougars and wolverines after they and their mothers have been freed. But, judging a similar pilot program in the Yukon, the majority should survive to breed themselves.

No one doubts that the lovely ungulates are under tremendous pressure and are threatened with extirpation, which means local extinction. Logging, hikers, development, avalanches, skiers and snowmobilers, along with predation by Nature’s efficient killers and competition from growing moose populations all contribute to the remarkable decline in caribou populations.

“This is death by a thousand cuts,” biologist Kelsey Furk told the North Columbia Environmental Society’s annual general meeting two weeks ago.

Herds once numbered in the hundreds in the Revelstoke area have shrunk estimates made in 2011 suggest there may be just 145 mountain caribou in three Revelstoke area herds. And the numbers are bad everywhere else, too. Only the Prince George area has more than 1,000 caribou in three herds.

A big part of the problem is that between nine and 13 per cent of the calves that are born each year don’t survive long enough to breed. The herds’ survival requires at least 15 per cent of their newborn to thrive in order to survive.

“Back in the 1980s and ’90s calves formed 20 per cent of the caribou population,” Furk said. “Quite a few more calves back then were making it to the 10-month stage.”

Because it’s impossible to limit all of the different pressures in order to help the tiny herds survive and grow, biologists came up with another approach: capture the pregnant cows in late March or early April and transport them swiftly to a predator-proof enclosure so they can safely deliver their calves. The mothers and their infants would be kept safe in the enclosure until the early summer (about two or three weeks after the last calf has been delivered) when they would be released.

Will it work?

A pilot project that ran from 2003 until 2005 in the Yukon found that calves delivered in a guarded enclosure had a 95 per cent initial survival rate, compared to just 33 per cent of calves born in the wild. (You can read more about the Chisana Caribou herd recovery Project and Captive Rearing Experiment by viewing the PDF below.)

“I’m excited by this,” said Furk, adding that the project, official known s the Revelstoke Caribou Rearing in the Wild Project,┬áis being organized by a consortium of organizations. They include: the Revelstoke Community Forest Corporation; Community Futures Development Corporation; the NCES, Parks Canada; the provincial government; Revelstoke Snowmobile Society; and the Columbia Mountains Caribou Research Project.

Project members already have a four-hectare site picked out north of Revelstoke and it has been brushed by provincial fire crews. They plan to fence it next year with an eye to capturing pregnant cows in 2014. So far they have have received $50,000 of in-kind donations but still need between $350,000 and $400,000 in financial support before they can actually begin the work of helping caribou populations recover.

Click here to view a PDF slide show about the caribou maternity program.