More than five years prior to this last crash, long fur was in high demand and single lynx pelts were selling for as much as $1,000. - $1,100. The lynx population has been under considerable pressure, and declining populations in the last century show every 10-year peak as being lower than the one before it.
Concern for its future viability required a management strategy from Poole's employer, the N.W.T. Department of Renewable Resources. Poole wanted to see how important a refuge that was off-limits to trappers might be for lynx to maintain healthy populations during their 10-year boom-and-bust cycles. The data obtained, he thought, could be used to convince trappers to set up no-kill refuges in parts of their own traplines, to protect the breeding stock of lynx. One way of undertaking such an inquiry is to establish a study area and capture and radio-collar lynx within it.
Having bloddied his hare for dinner, a lynx closes in for the kill. Lynx are not long dustance runners; they are quick only in short spurts and tend to stalk or ambush their prey.Then one can follow and map their movements to -- in the neutral language of biologists -- "ascertain their fates." If batteries outlive bodies, one can often recover radio-collared critters' remains for an autopsy. Death may come when a lynx strays outside the study area and is trapped; by predation within the study area; and also, in many cases, from starvation. Poole has found that the lynx die-off continues for two years after the hare crash. He now has seven lynx "on the air," equipped with radio collars, each one on a different frequency -- such as "770." During his trips into the 135 square-kilometre study area near Calais Lake, Poole, armed with a directional antenna and receiver, tracks the lynx every day and all day, taking compass bearings to establish locations which he later plots on a map.
-- Tony Stone Images/Vancouver
Pinned by a lynx's powerful claws, this hare will be dispatched instantly with one bite through the back of its neck. Lynx prey on other animals like grouse, mice and squirrels but when the hare population crashes, many lynx begin to starve. During a 1907 trip along the Athabaska River, Ernest Thompson Seton wrote of seeing many starving lynx, including one whose stomach contained part of a sparrow and a length of rawhide dog harness more than a metre long.
-- Tom and Pat Leeson/Photo Researchers
The 10-year cycle of life and death between populations of snowshoe hare and Canada lynx is an old story first recorded in the fur returns of early Hudson's Bay Company traders. The whole cycle pivots on the lynx's preference for hare flesh above all other. Lynx will eat grouse, ptarmigan, mice, voles, red squirrels, carrion and almost any other flesh. Yet when hares are plentiful, they eat almost nothing else. And when hares are scarce, although many lynx starve to death and few kittens that are born don't survive, some lynx have been found plump and healthy. "Why this is the case is still a mystery," says Poole.
Hares increase until the winter's browse is eaten bare. If you fell an aspen during this time and leave it lying, bunnies descend on it like fuzzy piranhas and nibble it bare. In response to intensive browsing by hares, most vegetation produces secondary compounds -- chemicals which make browsable plants less palatable and nutritious. The increase of these chemicals occurs in cycles and this too plays a role in triggering hare population crashes. As the food supply disappears, hares, like the lynx, will cannibalize their own dead. A hare's fat reserves are very slight. Weakened by hunger and cold, hares soon begin to starve to death. Lynx and other predators gorge on hares, and continue to breed, producing young at a peak rate until they run out of prey.
The hare die-off of 1990-91 began with slight trembling in the northern web of life centred on the Athabaska Basin, the area where changes in the hare cycle appear to happen first in North America. It is not clear why the cycle starts here. The ripple of mortality spread gradually outward across the entire region, extending westward.
The hare population crash was followed a year later by a decrease in lynx. The cats began to starve to death, and no new kittens survived after 1991. Younger lynx, particularly the yearling males, scattered in all directions, looking for better hunting grounds. One of Poole's lynx travelled all the way to Drayton Valley, Alta., about 1,000 kilometres south. Lynx from Snafu Lake (near Whitehorse) in the Yukon, a population studied by biologist Brian Slough, likewise dispersed, eastward over the mountains into Poole's territory.
Lynx crossing rocks and stream --
Photo courtesy -- Henry Holdsworth/F-StockSteven Fick/Canadian Geographic;
source: National Geographic Society
This exchange of genes ensures a natural diversity in the breeding stock. But Brian Slough would later suggest to me: "These long distance movements by lynx just might be the agent that synchronizes the cycle, as the expanding lynx population quickly crosses the continent." He notes that 18 lynx from his area have dispersed more than 100 kilometres, while 12 went more than 500 kilometres. A Snafu Lake lynx holds the travel record -- 1,100 kilometres; final destination -- Wood Buffalo National Park.
The older adults are the vitally important breeders, and they tend to remain on home ranges when the hares crash. "the yearlings of traplines just aren't as important to population growth," wrote Slough. That is why it is important not to trap mature lynx when the population is low. Both Poole and Slough believe that untrapped refuges will intensify the speed and magnitude of the lynx population increase, prevent local extinctions during cyclic lows, and maximize harvests over the long term. (I should point out also that there are remote lynx habitats in the north which trappers never venture into in the first place.)
Bare-handed despite the cold, Poole opens the cover of his compass to take a bearing. He is a former ski orienteering champion with a wall of medals in his Yellowknife home. -- Fran HurcombPoole plans to continue his research for at least another two or three years. But already he has added a great deal to scientific knowledge about the lynx. The lynx density he has observed is the highest ever recorded; he has documented the extensive movement and dispersal of a lynx population; and he has challenged the view of biologists who believe that all lynx trapping deaths are above and beyond those that occur naturally. In fact, he says, in the first year or two after the hare crash, many of the lynx harvested by trappers might have died of starvation anyway.
Poole said the lynx were not only predators, but victims who starved when their prey starved. He has found their emaciated bodies frozen in agony in the snow, and admits openly to mourning for ones that "went for a hike" and wound up in a trap.
A fter the great catharsis of hare mortality, plant growth slowly recovers, and with fewer predators present, the hare population begins to rebuild as forage improves.
Surviving adult lynx, finding more bunnies to eat, will begin to produce young again, and so the cycle continues as it has from time immemorial.
The lynx food in question, part of the family Leporidae (rabbits and hares) is a medium-sized hare, which attains a mature weight of about two kilograms. American biologist Lloyd B. Keith calls the hare a "... promiscuous, multilittered, seasonal breeder. Adult females produce two to four litters of one to nine young annually."
Hares are precocious and, unlike rabbits, are born above ground with eyes open, and bodies fully haired. The young leveret doubles its weight in eight days and is weaned by three weeks. Hares are crepuscular by habit, active after dark. Much of the day is spent on grooming and resting on the "form," a slight depression scratched out under a protective tree trunk or deadfall. Should a lynx flush it out, a hare will leap away with three-metre bounds, reaching speeds of 45 kilometres per hour.
The lynx, nocturnal enemy of the hares, is born blind and naked in a hollow under a deadfall log or some like shelter. The eyes of a kitten, small lamps lit in the timber, open after 10 days. In 12 weeks, the kittens can travel with their mother. They watch and learn where to look for hares and other game. Looking is important. A lynx's eyes are better than its ears or nose. Its quarry, supersensitive, responds to vibrations felt in the earth, and drums alarms on the ground with a hind foot. The lynx learns how to walk softly, how to catch a hare before it obtains top speed; how to pin the squealing hare with its big forepaws and bite through the back of its neck, killing it instantly. Another method in hunting the predictable hare is to simply wait in ambush along the runway. Lessons learned, the juvenile lynx strikes off to find a territory of its own. The males are generally solitary, except for the annual mating rites. Siblings, and daughters and mothers may share a range when hares are abundant.
Given enough hares, lynx will grow fat over the course of a winter. (Mature males weigh in at 12 to 14 kilograms, females 10 to 12 kilograms.) Their metabolism and thick coat is made for winter survival. The snow bears them up -- the hair on their paws is thick and stiff and forms a natural snowshoe -- while their predators, such as wolves, break through and flounder.
Full-body Lynx portrait by Art WolfeSid Marty, a journalist who lives in Lundbreck, Alta., has written extensively about Western Canada.
Canadian Geographic thanks Brian G. Slough for reviewing this article.
 | September/October 1995, pp. 28-37 Steven Fick/Canadian Geographic source: National Geographic Society |
 | and his book Leaning on the Wind |
 | Tom and Pat Leeson Art Wolfe |
 | |
 | photo credit on the web |
Thanks to 
Don Baccus for use of his photograph for background