The lynx of Vail Pass appear to be coexisting with forest users, for now

A population of lynx has made a home of Vail Pass areas less frequented by humans, and researchers want to know how new forms of recreation, like motorized snow bikes, will affect the cats moving forward.

Lynx researchers presented their findings to the Colorado Snowsports Museum on Wednesday as part of the museum’s “Through the Lens” speaker series.

Rudi Hartmann, a professor at the University of Colorado Denver, helped organize the event.

“Specifically, we want to address the question, and try to answer the question: Can the Canada Lynx, and the outdoor enthusiasts share the Vail Pass recreation area?” Hartmann said.

To address that question, Hartmann and the museum called in a few of the researchers who studied the lynx on Vail Pass and other areas of Colorado for decades and helped publish the 2019 Forest Service report titled “Winter Sports and Wildlife: Can Canada Lynx and Winter Recreation Share the Same Slope?”

Panelists included Jake Ivan, a senior scientist in the Mammals Research Section of Colorado Parks and Wildlife; Liz Roberts, a wildlife biologist with the White River National Forest; and Cal Orlowski, mountain sports ranger for the White River National Forest.

Animals of Vail Mountain

While lynx are native to Colorado with a well-documented history in the state, the cats started disappearing as settlers started inhabiting the area in numbers during the 19th and 20th centuries.

Early settlers made a big impact on lynx habitat in the form of logging and other heavy extraction activities, but the burgeoning recreation industry helped put the final nail in the coffin for the Colorado lynx in the 1960s and 1970s. Colorado’s last known lynx was illegally trapped on Vail Mountain in the 1970s when “an individual who first observed the animal while riding on a ski lift took a lynx illegally from the front side of Vail Mountain,” according to the Forest Service.

There were reports of lynx following the incident, but no lynx found.

“From ’78 to ’97 our agency conducted at least 11 statewide surveys to try to find evidence of lynx in the state, and didn’t come up with much,” Ivan said on Wednesday. “There were a few tracks that were potentially lynx, but the tracks were notoriously difficult to identify given conditions, and so we weren’t sure. But what we were sure of is if there were any present, we were down to the last handful of individuals.”

The decision was made to reintroduce the species in Colorado, an effort that began in 1999.

A successful lynx reintroduction had never occurred in the U.S. at the time, and for the first couple of years, the Colorado reintroduction was not successful either. But by 2002, methodology had changed, and biologists were happy with the low mortality rates they were seeing.

By 2010, researchers had documented third-generation Colorado-born lynx and were seeing a population of cats that was stable, if not increasing slightly.

“We had reintroduced lynx that had found each other and mated and produced kittens born in this state; that generation of kittens found each other and produced kittens; and that generation of kittens also found mates and produced kittens,” Ivan said.

On Vail Pass, those kittens have been seen and photographed by Forest Service rangers in recent years.

“We’re still finding them in areas that we collared them in 2010,” Roberts said on Wednesday.

Cautious optimism amid new questions

While the takeaways today are generally the same as detailed in the 2019 report, recreation has changed dramatically over the past few years, both in frequency of use and type of use, and new questions abound.

Recently reintroduced cats have a tolerance to recreation, researchers agree, but only up to a certain threshold. Lynx avoid areas where lots of ski and snowmobile activity takes place. Within the specific boundaries of the 55,000-acre Vail Pass Recreation Area, lynx are most apt to avoid areas where snowmobiles run snowboarders and skiers up to the high slopes. In the general Vail Pass area, lynx also avoid the in-bounds ski areas of Vail Mountain and Copper Mountain.

But the cats have found pockets of less impacted forest where skiing doesn’t take place in the general Vail Pass area, along with pockets within the 55,000-acre recreation area itself.

Those areas have become even more impacted in recent years, however, with motorized snow bikes able to navigate tighter trees than snowmobiles. But snowmobiles themselves, however, when not escorting skiers up the slopes and not staying in place for long, seem to be less bothersome to the cats than snowmobilers hauling skiers. That leaves the unknown question of how the newly popularized snow bikes are affecting the cats, Roberts said.

In studying the Vail Pass lynx from 2010 to 2013, Roberts said the animals would hunker down and stay in the pockets of terrain where they’re comfortable when snowmobiles were near.

“We learned lynx slowed their movement in the presence of a lot of snowmobile activity,” Roberts said. “They wouldn’t run away from the activity, they would really just slow down and … sometimes just watch.”

Roberts worked out of the U.S. Forest Service’s Minturn office during her studies.

“I spent many days in the Back Bowls of Vail tracking lynx just out of Blue Sky Basin,” she said.

Roberts worked on modeling lynx movement alongside the movement patterns of winter recreationists. The modeling helped her realize that “not every nook and cranny of that 55,000 acres was being used,” she said of the Vail Pass winter recreation area. “A lot of it was, but not everything. So we knew there were pockets in there that these lynx could co-exist.”

The reason the ski activity is more bothersome even than snowmobile activity has a lot to do with the areas where ski activity takes place.

“The best lynx habitat is these north-facing spruce fur,” Roberts said. “Well that’s the best skiing habitat too.”

Assuming, however, the lynx are able to maintain their co-habitation of the Vail Pass area with outdoor enthusiasts in the coming years, some of the other factors affecting their habitat might actually benefit the population.

As the forest begins to recover from the outbreak of mountain pine beetle which resulted in extensive lodgepole pine mortality in north-central Colorado from the late 1990s to about 2010 (depending on location), snowshoe hare could be more prolific, which means lynx have a better chance to survive, as lynx tend to mate in years when snowshoe hares are most productive.

“As time marches on and those forests start to recover, and you get a thick understory in the forest, I think we’re probably going to have more hares, and more hare habitat, than we’ve had in a long time,” Ivan said on Wednesday. “And it may turn out, in another few decades, to be a good thing for lynx.”