Meet the Lynx
The "Snowshoe Cat"

By Joshua O'Brian

The lynx is North America's original snow cat, a predator who stalks rabbits through snowy woods on four snowshoe feet and long, monster truck legs. It has become a staple of nature programs, which replay again and again its explosive skidding pursuit of a rabbit in snow, and of ecology textbooks for its boom and bust ten year population cycle that follows from its dependence on the hare. It's been described as "shy," "elusive," a "shadow animal," and a "ghost cat."

Despite its frequent public appearances on television and in books, you're a lucky person if you ever see a lynx in "real life" in the United States. That's because the lynx combines a wild cat's natural silence and shyness with a true rarity that is the result of both overtrapping and habitat destruction.

An Asian Immigrant

We have lynx at all thanks to the millions of years-old exchange in species across an intermittent Bering land bridge. Grizzlies, wolverine, musk ox, arctic fox, wolves and several other mammal species are found on both Asian and North American continents. (Not so long ago - about 12,000 years ago - North America also had camels, lions, cheetahs, and antelope species like those found in Africa. They too presumably crossed over the land bridge during a long past ice age.)

Lynx came to the North American continent from Asia at least twice. The first group of immigrants arrived about 2.5 million years ago, and learned to live in more southerly regions - as far as southern Mexico - eventually becoming the "lynx" which today we know as the bobcat. Our Canada lynxes represent the descendants of a much more recent group of lynx who arrived from Asia maybe 200,000 years ago.

The Two "Lynxes"

The bobcat and lynx are "sibling species," still close enough to one another in form and habits that they are one anothers' strongest competitors. Both cats are the same size (15-25 lbs) and general shape, and both can take the same range of prey. They share a continent, but split it up along a line that runs roughly along the Canadian border, and they rarely share the same territory. Since they won't coexist on the same piece of land, what determines which cat gets what areas? Temperament, or character, is half of the answer.

The lynx is a remarkably docile animal. Even when in a trap, a lynx will often sit passively or just tug quietly away as it is drugged or killed. Bobcats, maybe because they live in competition with a larger array of other predators, tend to be much more scrappy and pugnacious. It is thought that when the two meet in an area where either one could live, the lynx gives way in a confrontation with the bobcat.

The other half of the answer is foot size. Lynx feet are almost four inches across - twice the size of the bobcat's, and about the size of those of a cougar, an animal six times its size. They are covered with fur and act as snowshoes, allowing the lynx to survive in areas of deep snow where bobcats cannot. In the western United States, those areas are mostly mountainous, with the boreal forests and deep snow that are found more extensively in Canada, the center of the lynx's distribution.

Snowshoe Hare and the Snowshoe Cat

"Of all the Northern creatures, none are more dependent on Rabbits than is the Canada Lynx. It lives on Rabbits, follows the Rabbits, thinks Rabbits, increases with them, and on their failure dies of starvation in the unrabbited woods."

- Ernest Thompson Seaton, 1912

Without snowshoe hares there would be, quite simply, no lynx. Every lynx's body is a snowshoe hare graveyard - one that admits, in a good year, about 200 deceased rabbits. When its diet is less than 65% hare flesh, a lynx is probably facing starvation, and when it can, a lynx will eat nothing but hares.

What makes the lynx such a hugely successful rabbit catcher? Let me count the adaptations. Long legs and huge feet help it to stay on top of the snow, but so does its small size. Asian lynx, from whom our lynx descended, weigh about 50 pounds and hunt roe deer. In the past 200,000 years, our lynx have become half that size, and gained much snow flotation in the process. To detect prey they have developed exquisitely sensitive ears - some scientists suspect that the tufts of hair at the tips of their ears somehow act like antennae. The lynx also has eyes that are especially good at distinguishing between tiny differences in brightness - the better to see white rabbits sitting on white snow at twilight.

Lynx also have several hunting strategies. Mainly, they earn their daily (actually every-other daily) rabbit with a stalk and pounce, or short chasing attack. Other times, they rest, or wait in patient ambush by frequently used rabbit trails. And occasionally a group of females will team up to make a sweep through rabbit habitat, chasing together the hares that they flush.

Through much of Canada, snowshoe hare populations expand and then crash in a regular cycle. Starting at a population low, hare densities may increase up to 200 times as they mate and multiply like, well, like rabbits. Eventually, the hares outstrip their willow and birch food supply, starve in large numbers, and return to a low density until their sources of browse recover.

Lynx populations track those of their prey. While they are at a population low, lynx are barely able to hang on, and studies show that additional mortality from any source, including trapping, can be enough to push them over the brink into local extinction.

Trapping in the United States

In boreal forests of the western U.S., snowshoe hares are at the edge of their distribution. Instead of fluctuating, their populations remain stable at the equivalent of a permanent low. As a result, lynx populations in the western U.S. are always vulnerable to trapping.

Because of the way they hunt, lynx are easy to trap. The curiosity that serves them so well as professional hunters works against them when lynx investigate strips of cloth or Christmas tree ornaments that trappers hang above their sets. And because they don't hunt by scent, lynx aren't suspicious of human odors.

In the 1970s, changing fashions and the passage of laws protecting other exotic cats sent prices for lynx pelts to record highs. Trapping pressure increased everywhere, and western lynx populations crashed. In Montana, for instance, during the 1972-3 season, 300 lynx were taken, and as recently as 1983-84 the take was 69 cats. Now, across their entire range in the lower 48, there may be less than 1,000 lynx remaining.

Habitat Needs

Intentional trapping of lynx has been halted in all states but Idaho and Montana, leaving habitat destruction as the major threat to our few remaining lynx. Large-scale logging, road building, motorized recreation, and fire suppression keep whittling away at the areas that lynx find suitable as homes.

Food and reproduction are the two basic concerns all living things share, and lynx need habitat types that are suitable for both. Food is snowshoe hares, and hares subsist through the winter on shrubs and seedlings that are tall enough to stick up above the snow but not too tall for them to reach. Young stands have more plants of the right size, and hares are found at their highest densities in areas that have had about 20 years to recover from a disturbance. Since they hunt where the hares are, lynx too need patches of young forest.

For denning and raising their young, on the other hand, lynx need stands of mature trees. The high densities of downed logs and stumps, which can take hundreds of years to develop, provide cover for the kittens as they rest and play.

Ideal lynx habitat is a mosaic of old forest for denning, young forest for hunting, and corridors of forest that provide good cover for traveling through their territories. Periodic outbreaks of insects, blowdowns, and forest fires in the past produced a mixture of successional stages beneficial to lynx.

Human Impacts on Lynx

Disturbance human-style has a less benign impact on lynx habitat. Even when hunting, lynx prefer some cover and they typically won't cross openings more than 300 feet across. Clearcuts, ski resorts, and mining operations thus not only destroy huge blocks of habitat, but also act as effective barriers to lynx in their travels.

Like logging, fire suppression can produce forests of trees that are all of similar age, type and density, lacking the diversity needed to provide lynx with both denning and hunting opportunities.

Finally, almost all human activities in our forests bring with them increased numbers of roads. Roads by themselves fragment habitat by disrupting lynx travel and hunting patterns. They also destroy habitat for prey, increase access for hunters and trappers, and ultimately leave lynx with fewer and fewer undisturbed refugia.

Around the world, large carnivores and big cats especially are declining as humans turn ever more of the world to our own use. The lynx is now missing from almost its entire U.S. range. In working to protect and restore its habitat we have a chance, in our own backyard, to run counter to a disturbing global trend.