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.
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. 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.