The Wolverine: Addressing Conservation Challenges for a Rare, Long-Distance Traveler

In the Rocky Mountain states, wolverines once ranged widely throughout Colorado, Wyoming, Idaho, and Montana. Now, largely due to persecution by western settlers in the 19th and early 20th centuries, their range is constricted. The known breeding range of this second largest member of the weasel family (only sea otters are larger) no longer includes Colorado, and its southern boundary is in Grand Teton National Park.

Wolverines are short, compact, and powerful animals weighing 20-40 pounds, with males generally about a third larger than females. Like Canada lynx, their feet are large relative to body size, making them especially suited for snow travel. Like bears, their reproductive rate is low. Breeding commences at 4 years of age or older, occurs only every 2-3 years, and produces litter sizes of just over 1 cub on average. Like wolves, wolverines are highly territorial. Overlap of same-sex individual home ranges averages less than 1%. And like cougars, wolverines are independent and nonsocial for most of the year. But unlike other carnivores, wolverines naturally occur at super low densities. In the Yellowstone ecosystem, estimates suggest over 100 square miles of wildlands are needed to support one wolverine.

Long-term research in the Yellowstone region by the Wildlife Conservation Society (WCS) and others has revealed that just two breeding female and two breeding male wolverines occupy the entire Teton Range, where they prefer high elevation, rugged, and snowy terrain. They scavenge ungulate carcasses in winter, prey on marmots and other small mammals during summer, and den under the mid-winter snowpack in huge tree debris piles created by avalanches. Offspring accompany their mother for about a year before they disperse from the area.

Researchers also discovered that, owing to their low numbers on the landscape, dispersing wolverines must make large movements, sometimes traveling hundreds of miles in search of a mate and breeding territory and crossing low-elevation valleys between mountain ranges in the process. Recently, one radio-marked wolverine moved from just east of Grand Teton National Park to Rocky Mountain National Park in Colorado. These traits point toward a daunting challenge for long-term wolverine conservation, one that will involve coordinating large-scale land management decisions among many competing entities. Indeed, the wolverine may be the perfect poster child for promoting future wildland connectivity in the Rocky Mountains.

Planning for wolverine protection will require knowledge of their distribution and population trends. In an exciting new project, park biologists are collaborating with WCS on testing a noninvasive approach for conducting wolverine inventories. The technique, originally developed in Alaska, involves attracting animals to hanging bait where remote cameras are positioned to photograph individually unique markings and reproductive attributes. This enables researchers to determine sex and reproductive status of individuals. Hairs for DNA sampling are also collected at the site. By locating these stations in a systematic grid across the landscape and creating libraries of individual markings, DNA profiles, and numbers of lactating females, we hope to accurately estimate wolverine numbers and whether or not breeding is occurring in a given region. We believe that developing this technique is a critical step for effective wolverine conservation.

Steve Cain
Senior Wildlife Biologist
Grand Teton National Park

Bob Inman
Director, Greater Yellowstone Wolverine Program
Wildlife Conservation Society

The National Resources Defense Council recently highlighted Grand Teton National Park’s successful efforts to curb human-bear conflicts

Here’s what they had to say:

“First, Grand Teton National Park deserves a gold star. The park has greatly increased its staff and sanitation efforts as grizzly bear colonize areas south of Yellowstone. Grand Teton has developed a Wildlife Brigade comprised of two seasonal rangers and volunteers who worked skillfully to handle 215 bear jams this year. “Bear jams” are caused by bears being close to a road, where they attract the attention of road-bound tourists. These jams can be very dangerous; it takes careful management to keep people from getting too close to bears and creating risky situations for both people and bears. While this figure pales by comparison with the number of bear jams in Yellowstone (926 this year, a new record), it was still up significantly up from what has occurred in Grand Teton in the past. In addition, Grand Teton Park put out 62 new food boxes and 2,000 food storage notices out at trailheads.

Grand Teton officials are also spearheading an important piece of new work, a social survey, to evaluate the effectiveness of Bear Aware messages. This is important, because no one has undertaken a comprehensive assessment of the effectiveness of the information and education efforts that bear managers have been pursuing for many years. And the results may show how communications can be improved to foster greater human safety in bear country.

Adding to Grand Teton’s credit is the way the Park handles its annual elk hunt. Unlike other parts of the ecosystem where hunting is allowed, the park has had relatively few grizzly-hunter conflicts, probably due to several factors. First, all hunters are required to carry bear pepper spray —in contrast to the adjacent national forests, where most of the hunter-related bear conflicts occur. Second, “calling” by hunters (so as to sound like an elk) is not allowed, which reduces the chance that a grizzly will be drawn towards what it thinks is an elk – only to bump into a person, sometimes at a dangerously close range. Third, there is no bow hunting season. Archery hunters are especially prone to problems since they tend to sneak around in the woods in camouflage, silent and scentless, where they can easily surprise a bear at close range.”

To view the entire article, please visit The Natural Defense Council’s Staff Blog at (http://switchboard.nrdc.org/blogs/lwillcox/), article “Mounting Human-grizzly conflicts in Yellowstone: what can we do?”.

‘Tis the Season of Giving

Do you know someone who treasures Grand Teton National Park? Why not recognize their passion for this magical place during the holidays with a personalized bear box?

A gift of $1,100 funds a bear-resistant food storage box complete with a 3 x 5 inch stainless steel plaque to recognize the person you wish to honor. We will also send an irresistible stuffed bear with a card and information about why this campaign is so important. The Foundation has funded nearly 100 bear boxes, but 800 frontcountry campsites still need proper storage facilities. With increased visitation, the need for safe food storage is more important than ever.

Grand Teton is a place that restores us all—what better way to celebrate the season than to give back and give thanks for our park and its bears?

Reaching Beyond Borders to Protect Species Diversity

Migrations represent crown achievements of adaptation in the animal world and illustrate species’ natural shrewdness as they attempt to use seasonal resources in otherwise inhospitable environments.  Many examples of migration from Grand Teton National Park have been well documented:  short 20 to 60-mile local migrations of elk, moose, bison, and bighorn sheep; longer 75 to 150-mile regional treks of pronghorn and mule deer; and extreme flights of 2,500 miles or more by local red-tailed hawks to southern Mexico. 

Impressively, the now well-known Path of the Pronghorn, originally identified by park and Wildlife Conservation Society biologists, is used by about 300 pronghorn to complete the longest overland migration in the contiguous 48 states—Grand Teton National Park to Sublette County’s Green River basin.  These and other migrations, such as the wildebeest in Africa and gray whales in the Pacific Ocean, are revered wildlife spectacles.

Yet, despite their tremendous value, migrations have received little conservation attention, and losses continue to mount globally.  In the Greater Yellowstone Ecosystem alone, 75% of pronghorn migrations have already been lost, casualties of land development.  History has shown us that when animals migrate beyond the reaches of protected areas, like national parks, they are vulnerable.  In the case of pronghorn, delineating the migratory path through research resulted in several important conservation measures, including the first federally protected migration corridor in the history of the U.S. Forest Service.  The tie between science and conservation in this case is inextricable, and it provides a conservation model for animal migrations everywhere.  

Thanks to Foundation donors, park biologists are increasing their knowledge of animal migration with two new pilot projects.  The first kicked off in summer 2010 with the help of Craighead Beringia South, a local research and education institution, and will follow an osprey family from their summer home on Jackson Lake to their wintering grounds—likely in Central or South America—and back.  The real-time progress of these birds, fitted with super small, lightweight satellite radio transmitters, can be viewed here.  The second, planned for summer 2011, will follow mule deer from the high elevations of the northern Tetons in summer to their anticipated wintering areas in eastern Idaho and back.  Along the way, important movement corridors through private and public lands outside the park will be identified.

These movements form the cornerstone of migration conservation planning and the start of protection actions.  They are the beginning of a complicated route to success—one that involves many agencies, land owners, and competing interests that must work together to achieve a common goal.  Biologists will use these studies for long-term wildlife conservation planning specific to Grand Teton National Park.  In addition to providing park management with a basis for initiating discussions with stakeholders, these and other animal migration data from the park showcase the important relationship between protecting animal migrations and preserving species diversity in national parks around the globe.  In this way, even small but important local projects can have far-reaching benefits to national park units and the conservation of animal migrations in a broad range of geographical, environmental, and sociopolitical conditions.

Steve Cain

Senior Wildlife Biologist, Grand Teton National Park