As we approached, he began hurling himself against the mesh door. “Yup, he knows the drill,” Squires said, yanking it open. The lynx flashed past, his fuzzy rear vanishing into the trees, though he did pause to throw one gloating look over his shoulder.
The lynx team hopped back up on the snowmobiles for another tailbone-busting ride: they were off to a new trapline on the next mountain range over, and there was no time to waste. Squires ends the field research every year in mid- to late March, around when grizzlies usually wake up, hungry for an elk calf or other protein feast. Before long the huckleberries would be out, Cassin’s finches and dark-eyed juncos would sing in the trees, glacier lilies would cover the avalanche slopes. Lately, summer has been coming to the mountains earlier than ever.
Squires, who has blue eyes, a whittled-down woodsman’s frame and a gliding stride that doesn’t slow as a hill steepens, had never seen a lynx before starting his study in 1997. Prior to joining the Forest Service he had been a raptor specialist with the U.S. Fish and Wildlife Service. Once, when he was holding a golden eagle he’d caught in a trap, its talon seized Squires by the collar of his denim jacket, close to his jugular vein. A few inches more and Squires would have expired alone in the Wyoming sagebrush. He relates this story with a boyish trilling laugh.
Like raptors, lynx also can fly, or so it has sometimes seemed to Squires. During hunts the cats leap so far that trackers have to look hard to spot where they land. Squires has watched a lynx at the top of one tree sail into the branches of another “like a flying squirrel, like Superman—perfect form.”
Lynx weigh about 30 pounds, a bit more than an overfed house cat, but their paws are the size of a mountain lion’s, functioning like snowshoes. They inhabit forest where the snow reaches up to the pine boughs, creating dense cover. They spend hours at a time resting in the snow, creating ice-encrusted depressions called daybeds, where they digest meals or scan for fresh prey. When hares are scarce, lynx also eat deer as well as red squirrels, though such small animals often hide or hibernate beneath the snowpack in winter. Hares—whose feet are as outsize as the lynx’s—are among the few on the surface.
Sometimes lynx leap into tree wells, depressions at the base of trees where little snow accumulates, hoping to flush a hare. Chases are usually over in a few bounds: the lynx’s feet spread even wider when the cat accelerates, letting it push harder off the snow. The cat may cuff the hare before delivering the fatal bite to the head or neck. Often only the intestines and a pair of long white ears remain.
Lynx used to be more widespread in the United States than they are today—nearly half of the states have historical records of them, though some of those animals could have been just passing through. There have been population spikes in the recent past—the 1970s brought a veritable lynx bonanza to Montana and Wyoming, possibly thanks to an overflow of lynx from Canada—but heavy fur trapping likely reduced those numbers. Plus, the habitat that lynx prefer has become fragmented from fires, insect invasions and logging. In 2000, lynx were listed as threatened under the Endangered Species Act.
Squires began his project in anticipation of the listing, which freed up federal funding for lynx research. At the time, scientists knew almost nothing about the U.S. populations. Montana was thought to be home to about 3,000 animals, but it has become clear that the number is closer to 300. “The stronghold is not a stronghold,” Squires says. “They are much rarer than we thought.” Hundreds more are scattered across Wyoming, Washington, Minnesota and Maine. Wildlife biologists have reintroduced lynx in Colorado, but another reintroduction effort in New York’s Adirondack Mountains fizzled; the animals just could not seem to get a foothold. Bobcats and mountain lions—culinary opportunists not overly dependent on a single prey species—are much more common in the lower 48.
In the vast northern boreal forests, lynx are relatively numerous; the population is densest in Alberta, British Columbia and the Yukon, and there are plenty in Alaska. Those lynx are among the most fecund cats in the world, able to double their numbers in a year if conditions are good. Adult females, which have an average life expectancy of 6 to 10 years (the upper limit is 16), can produce two to five kittens per spring. Many yearlings are able to bear offspring, and kitten survival rates are high.
The northern lynx population rises and falls according to the snowshoe hare’s boom-and-bust cycle. The hare population grows dramatically when there is plenty of vegetation, then crashes as the food thins out and predators (goshawks, bears, fox, coyotes and other animals besides lynx) become superabundant. The cycle repeats every ten years or so. The other predators can move on to different prey, but of course the lynx, the naturalist Ernest Thompson Seton wrote in 1911, “lives on Rabbits, follows the Rabbits, thinks Rabbits, tastes like Rabbits, increases with them, and on their failure dies of starvation in the unrabbited woods.” Science has borne him out. One study in a remote area of Canada showed that during the peak of the hare cycle, there were 30 lynx per every 40 square miles; at the low point, just three lynx survived.