Colorado welcomes back the lynx
Colorado’s first lynx kittens in possibly several decades were found on May 21 about a thousand feet below timberline in the San Juan Mountains, little bundles of fur amid rotting logs draped with moss.
The five researchers who had scrambled up the treacherously steep hillside of spruce and fir trees found the mother tolerant of their brief intrusion. The pair of kittens, they said, still had their eyes closed, suggesting birth only a week to 10 days before. Already, they had the larger feet that helps distinguish the lynx from its cousin, the bobcat.
For Colorado’s lynx reintroduction program, this discovery was a milestone. Lynx are not only surviving, but also reproducing – 16 kittens in six different dens have been found this year, with more yet expected.
Wildlife biologists aren’t exactly bumping chests and high-fiving. Yet after two years of anxiously waiting for evidence of lynx – and becoming increasingly disturbed when none were found – they’re obviously excited by this year’s freshman class.
“You tend to second-guess yourself as things happen, and seeing the kittens was concrete evidence that at least at this time things are progressing well,” said Rick Kahn, director of terrestrial biology for the Colorado Division of Wildlife.
That careful optimism is in stark contrast to the program’s bungled beginning. With dozens of reporters from across the country looking on, wildlife biologists released the first lynx in February 1999.
The first seven promptly died of starvation.
Chastened biologists wondered if their critics, who were thick across the state by then, were right. Perhaps Colorado just had too little for lynx to eat. Perhaps the lynx was one species that wasn’t going to get back aboard this particular Noah’s ark.
The greater threat
As they reconsidered, they kept feeding the lynx, and as the snow receded they tried again. This next time in 1999, no lynx died. Now, four years later, starvation has been blamed for only two more of the 128 lynx now released. In fact, researchers have even found entire carcasses of snowshoe hare cached by lynx. That’s not exactly a hand-to-mouth existence. At least a portion of Colorado appears to have enough snowshoe hare, red squirrels and other small animals to support a lynx population.
Encounters with people, however, are the greater threat. Up to 10 lynx have been shot, up to eight have been squashed on roads – including two on Interstate 70 – 3 more have died by plague, and one was killed by a bobcat. Biologists just aren’t sure in the cases of 11 deaths.
If they were eating well enough, lynx did not immediately begin producing kittens. As shown in other wildlife reintroduction programs, biologists had suspected lynx would take time to get accustomed to their surroundings – something called “fidelity” – before starting families.
An added complication was that there were so few lynx. Although lynx seemed to return during mating season to the San Juans, that’s still a vast chunk of rugged real estate. And there’s no such thing as Singles Connection to link lonely-hearted lynx.
The Colorado Wildlife Commission suspended further reintroductions for a year, but then agreed to supplement the original release of 96 with an additional 170. These additional animals, say biologists, provide the minimum necessary to establish a self-renewing population.
Will they survive?
The next step is whether this year’s kittens, all the off-spring of lynx released in 1999 and 2000, will survive until going out on their own in about 10 months. In other words, will the mothers find enough to feed themselves and their little ones too? Perhaps none will survive to become adults, although Kahn optimistically says he hopes 50 to 60 percent will.
With two major milestones now, that question of kitten survival will be a third major test for the reintroduction program.
“The first hurdle was whether there was enough habitat and prey base for the lynx to survive,” says Rich Reading, director of conservation biology at the Denver Zoo, as well as a member of the lynx reintroduction advisory team. “The next step was whether the habitat was of high-enough quality for lynx to reproduce. The answer seems to be that at least some of it is. How much is of that high quality is still an open question.”
Another open question, one harder to answer, is how compatible lynx are with people of the 21st century. Nobody even truly knows how common lynx were a century ago, or exactly why they disappeared sometime in the last few decades. Some blame trappers exclusively, while others point to roads, suppression of forest fires and other reasons. But nobody really knows.
Ski area compatibility
Ski areas, meanwhile, have a great deal riding on the outcome of this experiment. Lynx and skiers inhabit basically the same niche, an elevation band of roughly 8,000 feet above sea level to timberline. Ski area operators want to believe that lynx and skiing are compatible.
So far, evidence of this compatibility is thin. Released lynx have been seen at the Arapahoe Basin, Keystone and Telluride ski areas. At A-Basin, the operator of a snow-groomer reported the lynx sat for some minutes, watching it idly. A ski-industry funded experiment in Canada’s Lake Louise area has drawn similarly optimistic conclusions about compatibility.
Retired wildlife biologist Gene Byrne, who launched the lynx reintroduction program, says he suspects lynx will ultimately be found to be compatible with people – as long as they aren’t shot or run over. After all, bobcats and mountain lions live on the edge of people, mostly unnoticed.
“They may not be that threatened by people,” he says. “People come out in the day time, and lynx are probably out hunting at night.
Rocky Smith of Colorado Wild!, who has read dozens of studies about lynx, all but one conducted in Canada, remains skeptical of lynx and ski area compatibility.
“It’s way too premature to draw a broad conclusion,” he says.
So far, about the only clear conclusions that can be drawn is that the lynx are eating well. Wildlife researchers following their trials have found evidence the last two winters that snowshoe hares have accounted for 87 percent of their diets, supplemented by red squirrels, a pine marten and a weasel.
High, rugged terrain a theme in lynx dens
Steep hillsides, dead trees and a large pantry of snowshoe hare hopping about seems to be the theme for six dens where 16 lynx kittens have been found so far. Another consistency is high elevations – all have been found at between 10,000 and 11,200 feet above sea level.
The case of the first lynx kittens illustrates the theme. Researchers say they knew where to look because the mother was still wearing a radio-collar installed before her release, emitting a signal that was picked up telemetrically. The signal’s proximity to a similarly radio-collared male had been noted several months ago. When the female’s signal became stationary in May, it suggested kittens.
Closing in on that signal, the researchers bushwhacked up the steep, northeast-facing hillside of downed and standing spruce and fir trees. The den was found underneath an Engelmann spruce. The site was similar in elevation and vegetation to some ski slopes at Vail and Beaver Creek, but on a slope that was far steeper.
“You couldn’t ski down that slope,” says Rick Kahn, head of the Colorado Division of Wildlife’s terrestrial research program.
Most of the kittens have been produced by pairings of lynx released in Colorado in 2000. Some dens have been relatively close to trails, while others have been in the most “remote, steep, nasty areas of blowdown you can possibly imagine,” says Kahn.
More kittens could yet be found. Lynx give birth through June, and radio signals transmitted from the collars suggest nine male-female lynx pairings this past winter. That means three additional litters remain possible.
Although biologists had known that it might well take several years for lynx to begin reproducing, they had been getting uneasy when no kittens were found during the last two years. More frustrating yet, they had evidence suggesting matings during both winters.
To have kittens, lynx need to establish territory and establish “fidelity” to that territory, explains Todd Malmsbury, spokesman for the Colorado Division of Wildlife. This seems to take two or three years
“People had a lot of false expectations that the lynx would bound out of the boxes immediately, breed immediately, have young, and everything would be fine,” says Malmsbury. “But that is rarely the case, particularly with species such as the lynx, which has a very specific needs and prey base.”