scarcity, especially in winter. The wolverine is also a powerful and versatile predator. Its prey mainly consists of small to medium-sized mammals, but the wolverine has been recorded killing prey such as adult deer that are many times larger than itself. Prey species include porcupines, squirrels, chipmunks, beavers, marmots, moles, gophers, rabbits, voles, mice, rats, shrews, lemmings, caribou, roe deer, white-tailed deer, mule deer, sheep, goats, cattle, bison, moose, and elk. Smaller predators are occasionally preyed on, including martens, mink, foxes, Eurasian lynx, weasels, coyote, and wolf pups. Wolverines have also been known to kill Canada lynx in Yukon, Canada. Wolverines often pursue live prey that are relatively easy to obtain, including animals caught in traps, newborn mammals, and deer (including adult moose and elk) when they are weakened by winter or immobilized by heavy snow. Their diets are sometimes supplemented by birds' eggs, birds (especially geese), roots, seeds, insect larvae, and berries. Wolverines inhabiting the Old World (specifically, Fennoscandia) hunt more actively than their North American relatives. This may be because competing predator populations in Eurasia are not as dense, making it more practical for the wolverine to hunt for itself than to wait for another animal to make a kill and then try to snatch it. They often feed on carrion left by wolves, so changes in wolf populations may affect the population of wolverines. They are also known on occasion to eat plant material. Wolverines frequently cache their food during times of plenty. This is of particular importance to lactating females in the winter and early spring, a time when food is scarce. Natural enemies Wolves, American black bears, brown bears, cougars, and golden eagles are capable of killing wolverines, particularly young and inexperienced individuals. Wolves are thought to be the wolverine's most important natural predator, with the arrival of wolves to a wolverine's territory presumably leading the latter to abandon the area. Armed with powerful jaws, sharp claws, and a thick hide, wolverines, like most mustelids, are remarkably strong for their size. They may defend against larger or more numerous predators such as wolves or bears. By far, their most serious predator is the grey wolf, with an extensive record of wolverine fatalities attributed to wolves in both North America and Eurasia. In North America, another predator (less frequent) is the cougar. At least one account reported a wolverine's apparent attempt to steal a kill from