The Eurasian Lynx, the Canadian Lynx, the Bobcat and the Iberian Lynx are the four species within genus Lynx, and a great introduction to how evolution and natural selection work. All are descended from the extinct Issoire Lynx, which originated in Africa during the late Pliocene about three million years ago, about four million years after lynx ancestors separated from the ancestors of cougars. The Issiore Lynx, stockier with a longer neck, but shorter limbs than its descendants, may be the bridge between the Lynx and the larger cats. The Iberian Lynx, the most endangered cat in the world thanks to hunting, trapping and habitat loss, appears to be directly descended from the Issiore Lynx. The Eurasian Lynx entered North America across the Bering Land Bridge about 2.5 million years ago, in two waves, near the dawn of the Pleistocene, setting the stage for the bobcat and the Canadian lynx.

Changes on planet Earth, wrought  through plate tectonics, and its consequences, volcanoes and earthquakes, along with rivers and the gradual filling, draining or evaporation of large bodies of water, may lead to separation and isolation of a group of any individual species. In this case, glaciers and ice sheets waxed and waned, alternately blocking and opening Beringia, as well as migration paths down to what would become the U.S. border and Canadian province areas, a classic example of how one species gets separated by changing land and sea features, the two groups then evolving in different directions, until representatives of one group can no longer mate, thus resulting in two species. The southerly group of Eurasian Lynx evolved into the bobcat, which assumed a form very close to what they are today by 20,000 years ago, while the more northerly group, following the melting of ice sheets and the opening of boreal forests, evolved into the Canadian Lynx.

The Canadian lynx is smaller than the Eurasian Lynx, and slightly shorter than the bobcat. What is most interesting in these developments is that Canadian Lynx not only evolved into specialty predators, largely dependent on snowshoe hare, but, as Christina Eisenberg pointed out in “Carnivore Way”, if you compare the skeletons of the Canadian Lynx and the snowshoe hare, while covering the skulls, at first glance, their skeletal structures appear similar, almost like an arrangement where one was literally evolved to chase the other. The wonders of natural selection and evolution.

On the other hand, it also means that Canadian lynx populations are almost entirely dependent on the populations of snowshoe hare, not exactly a good place to be, in a world where the addition of competition from other predators, like bobcats, human hunters and trappers, as well as climate change may cause havoc with the availability of various wildlife populations. There are rare examples of hybridization between lynx and bobcats, so you might quibble and claim that the two are not yet completely independent species. You will meet both bobcats and a female Eurasian Lynx named Kayla, when you visit the Adirondack Wildlife Refuge.

The bobcat is a uniquely North American cat, with most concentrated inside U.S borders, while a thinner range sweep east from a central tongue stretching into northern British Columbia, dipping south to cross the country maybe 75 miles north of the US. border, before heading northeast to the Gaspe Peninsula, where the St. Lawrence meets the Atlantic. It is more of a generalist as a predator, as is the Eurasian lynx. When climate change leads to a narrower calendar range of regional snowfall, and less depth accumulation overall, lynx move further north and to higher elevations, while the bobcat moves in, a trend observed in both British Columbia and Ontario.

As with most mammals, male lynx are larger than females, an example of sexual dimorphism. Following Bergman’s Rule, lynx in colder northerly climates are larger on average than their more southerly counterparts, as larger animals retain body heat better than smaller ones, and therefore are more likely to live to breed, and pass along that larger size. Eurasian lynx evolved to pursue larger prey, everything from caribou to roe deer to smaller mammals, and average 40 to 66 pounds, 28 inches tall at the shoulder and between 34 and 51 inches from nose to tail. Larger animals like caribou are killed by crushing the esophagus with the jaws and holding on until asphyxiation kills the prey.

Canadian lynx are significantly smaller, ranging from 18 to 31 pounds, 19 to 22 inches tall at the shoulder and 36 inches in length, while the stockier bobcat is 16 to 31 pounds, 20 to 24 inches tall at the shoulder, and 28 to 39 inches long. Why such a disparity between the Eurasian Lynx and its descendants?

Predators tend to evolve to a size most advantageous to their ability to make a living, and it stands to reason that Canadian lynx found their perfect prey in the snowshoe hare. Survivors get to breed, so surviving, breeding Canadian lynx, facing deer larger than the roe deer the Eurasian lynx get to pursue, came down closer in size to its main prey, the snowshoe hare, and thanks to exaggerated snowshoe-like paw width, developing much better mobility in the snow through which they pursue their most common prey.

While bobcats generally prey on smaller mammals and rodents, leaner prey periods may cause them to take greater risks, and go after larger, more challenging prey like fawns, fox, female fishers, swans, domestic cat and small dogs. Studies in Maine indicate that male fishers have more success killing lynx than the bobcat, who often turns the tables on the aggressive fisher. Bobcats are the main predator of the whooping crane.

Canadian lynx live in habitats that are further north and endure longer periods of deeper snow than do bobcats. In fact, not only do bobcats have narrower paws than lynx, who carry the added advantage of fur between the footpads to add in warmth and stability on ice and snow, but lynx in the far northern part of their range, also have wider paws than lynx living closer to the U.S. border.

Natural selection tends to happen slowly over thousands and millions of years, while the spread of humans, with our heavy impact on habitat, happened relatively overnight. In addition, snowshoe hare numbers wax and wane in ten year cycles, ranging from an incredible six thousand per square mile to about thirty psm, so while bobcats naturally pursue snowshoe hares, their more generalist hunting behavior means their survival is not so tied to the one species of prey. Lynx are basically nocturnal hunters, and typically move five to six miles per night, as well as being great swimmers and climbers, using trees for escape, not pursuing prey.

Lynx grow seasonal coats, with Summer coats tawnier and browner, while thicker winter coats are grayer with spots fading and less well defined. All species of lynx feature two inch hair tufts extending from the top of the ears, which helps in directing sound to the ears and feeling where stems and brush occur, aiding in the direction of travel or locating places to wait out bad weather. Fur growing out the lower cheek area forms a long ruff in winter, resembling a Fu Manchu beard, which helps in staying warm, also detecting brush and branches. Lynx have four nipples.

While the slightly longer bobcat tail has a white tip, the two to six inch lynx tail has a black tip. Lynx have twenty eight teeth, including four carnassials to aid in tearing flesh and muscle tissue. The jaw is missing the upper premolars to allow deep penetration by the incisors, and tearing by the carnassials, which is why it often looks as though they’re chewing with the side of their jaws. The flexible distance between the metatarsals allow the toes to spread moving through snow and let the paws stretch to four inches wide.

As with male cougars, Canadian lynx males have large territories, which are affected by topography, availability of prey, the number of other male lynxes, among other factors. Male territories average fifty to ninety miles, overlapping several female territories, which average twenty to forty square miles.

Canadian lynx mate between March and May, the farther north the female, the later she’ll go into estrus for only three to five days. Females will mate with only one male, while males mate with multiple females. Gestation period is sixty days, and one to four kittens will be born, in a prelined den in heavy brush or under ledges or logs. Kittens are born blind for the first two weeks, and average less than half a pound at birth. They start leaving the den at five weeks, and begin hunting on their own at about eight months. By ten months, they’ll be on their own, and fully grown by two years. Males take no part in raising kittens.

Steve Hall