Nature’s Snowshoes Propel Rare Critter

The lynx tracks descended into a shady lodgepole forest, pungent with pinesap on this unseasonably warm winter day, and then passed cone shavings left by a red squirrel – a possible meal for the lynx though the cat prefers snowshoe hare.

Wildlife biologist Nate Berg crouched next to the tracks and inserted a gloved hand into the sugary snow. He gently sawed around the depression and popped out a snowy cast, less than 2 inches thick.

That was all the evidence Berg needed to confirm that he was indeed on the trail of a lynx. With their big feet and lightweight bones, lynx are specially designed to live in deep snow. The elusive animal virtually floats atop the powdery surface thanks to thick cushions of fur padding the soles of its large feet. A cougar or bobcat would leave a deeper imprint.

Given the lynx’s natural attributes, Berg and fellow researcher Rachel Gray loaned me a pair of snowshoes – I’m typically a skier – to track one of the cats through the woods. Berg and Gray started looking last winter for lynx in Wyoming’s Bridger-Teton National Forest, which abuts Yellowstone and Grand Teton national parks. Berg, Gray and fellow wildlife biologists Jennifer Burghardt and Boone Smith formed the Endeavor Wildlife Research Foundation to drum up funding for the project and to oversee the research.

Proving the presence of lynx on this forest was not a given when the four biologists decided to start looking. Since a radio-collared lynx, nicknamed George, died several years ago in the Wyoming Range, on the southern end of the forest, some had speculated that lynx could no longer make a living here. Logging, grazing, wildfire prevention, recreation and other activities have all altered the landscape for lynx.

But the Endeavor biologists were optimistic after spotting possible lynx tracks during fieldwork studying cougars and other wildlife on the forest. Also, Berg had worked on a lynx survey in Yellowstone National Park where researchers had confirmed the presence of the species there.

Wyoming’s Bridger-Teton forest, covering 3.4 million acres, marks one of the southernmost ranges where the cat still occurs naturally. Further south, the Colorado Division of Wildlife has been trapping lynx in Canada and transporting them to the state as part of a reintroduction program begun in 1999.

On the day I joined Gray and Berg to look for the 11 to 40 pound cat, with a bobbed tail and tufted ears, we explored the Togwotee Pass area, sandwiched between the Teton and Gros Ventre Wildernesses. After carving out the snowy cast of the lynx’s track and measuring the track, stride and straddle, we followed the powdery impressions to where they merged with a snowmobile track. We entered an old clearcut where logged stumps had given way to young trees as profuse as toothbrush bristles. Lynx typically prefer clearcuts that are at least 30 years old when seedlings have grown into trees tall enough to protrude above the snow.

“It’s because the bunnies like it thick,” Berg said. “The [lynx] are hanging out where the rabbits are.” And rabbits live on pine needles.

The researchers are enthused as they see the tracks headed toward a camera, which the team had attached to a tree with a motion sensor. Berg and Gray, who were on skis, decided to ski to the camera to see if they had caught the lynx on film.

Meanwhile, I joined two snowshoe-equipped research technicians, J.T. Richards and Eric Bindseil, deeper into the woods to backtrack the lynx’s journey. I struggled to keep up with the more experienced snowshoers as they maneuvered gracefully down steep embankments, lumpy with snow-covered downfall. As we moved from the clearcut into a more mature forest, we hauled ourselves up and over countless downed logs with just enough white stuff to disguise the tops of foot-tangling branches and cavernous holes beneath. We kneeled and wriggled through webs of tightly entwined branches.

The older forest, with lots of shrubs under the treed canopy, offered good cover for the lynx, and the researchers found several places where the cat had stopped to rest or to wait in ambush for prey. At each frozen depression, or day bed, where the cat had lingered, the researchers picked over the snow looking for wispy, white hairs. They also kept an eye out for scat.

Researchers send the hair and scat to a lab in Missoula, Mont., which runs DNA tests to confirm the critter was a lynx and, in some cases, identify a particular individual. Past scat samples collected by Endeavor biologists have matched the genotype of a male, who left his DNA calling card in Yellowstone Park in the winter of 2003-04. The researchers have found the same male’s DNA several times this winter and last, indicating he may be a resident of the Greater Yellowstone Area. Discerning whether lynx are living in the Greater Yellowstone and successfully raising young or whether they’re just passing through could be an important find.

The U.S. Fish and Wildlife Service listed lynx as a threatened species in 2000. As part of efforts to conserve lynx, the federal government is proposing designating approximately 26,935 square miles as critical lynx habitat in portions of northern Maine, northeastern Minnesota, northwestern Montana, a small portion of northern Idaho and western Washington. While the Bridger-Teton marks the southern end of lynx range, the forest has not been included in the draft designation. (The service is taking comment on the proposed habitat designations through Feb. 7.)

Critical habitat or not, learning more about lynx could help Bridger-Teton managers make more-informed decisions about how to manage for the rare species. Forest managers acknowledge that they know little about even the species’ distribution on the forest.

Lynx are so rare and shy, researchers often never see the cats they track. On our outing, we didn’t even scare up some scat. What’s more, the lynx tracks passed very near the camera station where researchers had hung shiny pie tins and a fake mouse from a tree as a visual lure and used beaver Castor oil and catnip as a smelly enticement.

The lynx didn’t take the bait. Instead, it headed through an open meadow, just skirting the station and the camera’s remote sensor. Even without a snapshot at the end of the day, I had a better feel for the elusive critter having snowshoed a little ways in its tracks.

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Rebecca Huntington