Last Stand in the Selkirks
For most people, the word caribou conjures visions of vast herds of animals and the thunder of tens of thousands of hooves across the barren lands of the Far North. But set your coordinates 20 degrees further south to northeast Washington, the Idaho Panhandle and southern British Columbia where you will find caribou of a different sort. Unlike the great migratory herds of the tundra, the mountain caribou that wander the regions Selkirk Mountains travel in small bands. They are among the most endangered mammals in the United States and are protected under the Endangered Species Act. An aerial census taken in March 2008 found a total of forty-six animals in the group.
The Selkirk Mountains caribou are the last holdouts of Americas native caribou population, which before 1900 were found in northern New England, the Great Lakes area of the upper Midwest, northeast Washington, northwest Montana and Idaho, ranging as far south as the Salmon River. The Selkirk caribou herd is unique because it is the United States portion of a larger population of woodland caribou (Rangifer tarandus) that has adapted to living at higher elevations.
Historically, mountain caribou occupied the forests and mountains of southwest British Columbia from the Alberta border through the Okanagan highlands, and from northeast of Prince George, south into northeast Washington and northern Idaho down into central Montana. Today, they have vanished from more than half of their original range. They number about 1,900 animals in thirteen populations that are made up of anywhere from a dozen to 400 or 500 animals. Mountain caribou disappeared from Montana by 2002, but they still hang on in Idaho and Washington.
The Selkirk herd is sometimes called the international herd because it wanders back and forth across the border between Canada and the United States. About half the herds 945,264-acre range is in Washingtons Colville National Forest and the Idaho Panhandle National Forests, which include the Coeur dAlene and parts of the Kaniksu and St. Joe National Forests. The rest is in British Columbia. Because this herd represents the last of the caribou population in the United States, it has been the focus of a long-term recovery effort by the federal government, Washington and Idaho wildlife officials and conservation organizations, along with assistance from their Canadian counterparts.
Mountain caribou do not migrate long distances across the landscape as do their tundra and woodland cousins. They are elevational migrators, moving to different altitudes according to the season, generally staying above 4,000 feet. Deer and elk migrate down slope in the winter, but caribou move upslope, says Jim McGowan, wildlife biologist for the Colville National Forest. That gets them away from competition and also from predators like wolves and mountain lions.
This strategy, unique among ungulates, has allowed them to survive in harsh, snowy environments. But it has also made them vulnerable to a series of threats, including old-growth forest logging that has reduced their habitat; increased exposure to predators; and growing motorized activity that is bringing more people into what was once their snow-locked winter refuge.
Keyed to old-growth forest habitat, spring finds Selkirk caribou in the lowlands feeding on the years new plant growth. As the summer sun melts the mountain snowpack, the animals move to feed on high country vegetation. As winter returns to the mountains and the new, soft snow makes it difficult for the animals to move around, they retreat down to the snow-interception zone, where the dense old-growth tree canopy limits accumulation on the forest floor. By January, as the snow in the 7,000-foot heights consolidates and hardens, the animals climb back into the subalpine fir zone. Their large hooves allow them to walk on top of packed snow and move efficiently across the winter landscape. Safe from predators, they wait out the frigid months, feeding on lichen that is too high in the tree branches for them to reach the rest of the year.
Although no early counts were made of the Selkirk herd, wildlife biologists estimate the historical population was probably around 200 to 300 animals, based on the capacity of habitat conditions. But by the 1970s, the population was declining. In 1983, with the population down to about twenty-five animals, the Selkirk Mountains caribou were listed under the Endangered Species Act. In 2002, Canada listed them under their Species at Risk Act. Decades of human activities had clearly taken a disastrous toll on the herd.
BALANCING PREDATORS AND PREY
Historically, mountain caribou were probably never abundant. Their migration life history has been key to their survival as a species. From an evolutionary standpoint, caribou behavior is to avoid predators since they dont do well up against them, says Wayne Wakkinen, senior wildlife research biologist for the Idaho Department of Fish and Game. Theyre in the 6,000 and 7,000-foot elevation levels in February and March not because they are getting fat up there. Its because they can avoid predators.
But that complex dynamic began to change in the 1960s. Increased logging was opening up more of the forest canopy in caribou habitat, which stimulated new growth of grasses, shrubs and small trees that wild ungulates feed on. Along with forest openings created by wildfire, these areas produced new food sources, and wildlife responded. White-tailed deer, never particularly common in the Selkirks, moved in to share the bounty.
A more serious complication than competing for food was the deers primary predator, mountain lions, which followed the deer into the new territory. Almost overnight, mountain caribou found themselves confronting a new, dangerous and efficient predator. By the mid-1990s, fueled by the abundance of white-tailed deer, mountain lion populations expanded, peaking in 1997. The predators killed a lot of caribou between the 1980s into the early 2000s.
They were having a tremendous impact on bighorn sheep, mountain goats and caribou, says Tim Layser, a wildlife biologist with the Idaho Panhandle National Forests.
For most wild ungulate populations, such as deer and elk, mortality rates tend to be highest in spring and winter. In the spring and early summer, young calves and fawns are vulnerable to predators. In winter, starvation-weakened ungulates are easy game for predators. But researchers who studied Selkirk caribou mortality found a different pattern. They were seeing the highest predation rate among mountain caribou in late summer and early fall, with July, August and September being peak mortality months.
That caught us off guard, says Wakkinen. We didnt expect to see high mortality at that time of year. But the explanation turned out to be straightforward. Changes in the habitat altered the historical predatorprey complex; open areas created by the increase in logging attracted deer to the caribous high-elevation range, and mountain lions followed the expanded deer population.
There is now an overlap between caribou and predators in late summer and early fall, Wakkinen says.
The changes in the complex predatorprey relationship were found throughout the mountain caribous Canadian range. The trigger was the same, although as one moves north, the predatorprey dynamic switches from a white-tailed deermountain lion to a moosewolf scenario. In the Revelstoke area, for example, logging helped create fertile habitat for moose, and their population increased from 400 to 1,600, says Lawrence Redfern, outreach director for the Mountain Caribou Project, a British Columbia conservation organization. Wolf numbers increased, too. That put predation pressure on the caribou that they didnt have before, he says.
COMPETING WITH SNOWMOBILES
One of the most controversial aspects of mountain caribou recovery has centered on winter recreation activitiesespecially snowmobilingwithin the Selkirk recovery area on both sides of the border.
The popularity of snowmobiles has increased dramatically in caribou country, and because of their open, mountainous terrain, the Idaho Panhandle National Forests are a favorite destination for snowmobile enthusiasts who seek to ride big open bowls and high side steep ridges for thrills. Todays more powerful snowmobile engines can be ridden much higher into the mountains, and deeper into the caribous winter range.
Snowmobiling has become an important part of the regions winter tourism economy, with unfortunate consequences for wildlife. Caribou are negatively impacted by snowmobiles, says Mark Sprengel, former executive director of the Priest River, Idahobased Selkirk Conservation Alliance. Snowmobiles as far away as a half-mile can cause caribou to flee, although deliberate harassment of the animals by snowmobilers has not been an issue. Its a time of year when they are stressed and need to conserve energy. When you chase them out of an area with snowmobiles, they are wasting energy, Sprengel says.
Its more of a problem than it used to be, and the problem is increasing, says McGowan of the Colville National Forest. We are getting snowmobiles into areas that we didnt worry about fifteen years ago because they couldnt get way out there. While the Colville and Idaho Panhandle national forests are all experiencing skyrocketing snowmobile use, the Idaho Panhandle is feeling more of an impact because snowmobilers are drawn to its more open terrain.
Increased snowmobile use is also an issue for mountain caribou in British Columbia. Heli-skiers and skiers using the backcountry yurt system are often transported via snowmobiles as well.
The U.S. Forest Service has tried to keep snowmobiles and caribou apart by establishing closed areas, but problems remain. The Selkirk Conservation Alliance and Project Lighthawk, which provides airplane services for environmental advocacy groups, began a winter aerial monitoring program on the United States side of the recovery area in the early 2000s and documented regular incursions by snowmobile riders.
In the snowmobile community there are people who like to push the limits and pioneer new trails, says McGowan. You are always going to have a certain percentage of people who dont think the rules apply to them.
Dissatisfied with the Forest Services efforts, conservation groups sued the agency and the U.S. Fish and Wildlife Service in fall 2005, charging that protections required by the Endangered Species Act were being violated.
Ruling in their favor, the court ordered the Forest Service to stop grooming additional snowmobile trails in the the caribou recovery area for the remainder of that winter. The judge also ordered the agency to restrict snowmobile use until the Idaho Panhandle National Forests developed a winter recreation plan to address snowmobilemountain caribou issues. In 2006, the court prohibited all snowmobile use within the recovery area until the plan is completed. The ruling halted snowmobile use on about 330 miles of trails, but left about 800 trail miles still open.
ONE STEP AT A TIME
Caribou recovery has involved a series of ongoing actions, from predator control to habitat recovery. In response to increasing predation rates by mountain lions, the Idaho Department of Fish and Game, Washington Department of Fish and Wildlife and British Columbia officials increased hunting pressure on the animals to reduce their population. We think we have a good handle on mountain lion numbers, Layser says, although biologists are watching the increase in wolves to monitor any impacts on the caribou.
Long-term recovery of old-growth forests and reducing forest fragmentationwhich should eventually alleviate the predation issueare fundamental recovery strategies, along with developing a winter recreation plan that limits snowmobile use. The Idaho Panhandle National Forests will release a draftSelkirk Mountains Range Winter Travel Planfor public review and comment in fall 2008.
Artificially increasing caribou populations is another strategy. Between the late 1980s and late 1990s, the Selkirk herds numbers were boosted by transplanting animals from healthier herds in British Columbia, but herds that have caribou to spare are in short supply. Any extra animals will probably go to British Columbias south Purcell Mountains, just east of the Selkirk Mountains, where the caribou population is down to a dozen and will almost certainly disappear within a decade without augmentation.
International cooperation is critical. The United States has a recovery plan as required by the Endangered Species Act, and British Columbias Ministry of Environment will soon be releasing its plan. The International Mountain Caribou Technical Committee serves as a clearinghouse of ideas and information for caribou recovery for both countries. To become sustainable and avoid extinction, biologists estimate that the Selkirk caribou population will need to grow to at least 200 animals.
The efforts on behalf of the Selkirk caribou are showing positive, if incremental, response. Biologists conduct a yearly aerial census to keep tabs on the herds population, which has been increasing by three or four animals each year. The international herd, says Redfern of the Mountain Caribou Project, has been one of our success stories.
One of the most positive developments for the herd came in summer 2008 when the Nature Conservancy of Canada purchased 250,000 acres of wildland in south-central British Columbia. Formerly owned by a timber company, the Darkwoods property, which makes up a significant portion of the Canadian side of the Selkirk caribou recovery area, will be managed for natural and wildlife values. That was a huge step for recovering our caribou, says Layser. Still, at forty-six animals, the Selkirk caribou population is precariously low and vulnerable to catastrophic eventssuch as a wildfirethat could reduce their numbers below the point of no return.
As wildlife biologists continue their recovery workfunded by the U.S. Fish and Wildlife Service, Washington Department of Fish and Wildlife, Idaho Department of Fish and Game, the Forest Service and the British Columbia Wildlife Branchconservation organizations are paying close attention. The Selkirk Conservation Alliance will continue to monitor snowmobile use to ensure that snowmobilers are obeying travel restrictions. And because high elevation late succession forest habitat is so crucial to caribou, conservation groups are scrutinizing proposed timber sales within the caribou recovery area.
We have consistently opposed old-growth logging in the Idaho Panhandle, says Mike Petersen, executive director of The Lands Council, a conservation organization based in Spokane, Washington. We oppose old-growth logging in roadless areas that tend to be at higher elevations where the caribou are.
One of the difficulties in mountain caribou recovery is the lack of public awareness. Many Washington and Idaho residents have no idea there are caribou in their states. Thats frustrating for Jerry Boggs, current executive director of the Selkirk Conservation Alliance, who sees mountain caribouwith their requirement for old-growth forestas a counterpart to the northern spotted owl. In his view, the caribous lack of name recognition has slowed restoration efforts. And introducing the American public to mountain caribou is proving to be a challenge. In 2003, Boggs tried to convince several major national conservation organizations to adopt mountain caribou as one of their signature animals, hoping to harness more political clout and fundraising expertise on the animals behalf. There were no takers.
The biologists know how to recover mountain caribou, says Boggs, but it requires good funding and especially the political will. Weve never had that because weve never had the public support. Weve never had a good public relations campaign for caribou.
Despite the many challenges, the Selkirk herd is slowly building. Predation is under control, snowmobile groups are cooperating with conservation efforts and caribou habitat, with proper management, will eventually come back. Recovery is still far off, but barring any unforeseen catastrophesnatural or human causedthe future will likely see more mountain caribou roaming the Selkirk Mountains.