What food is available for the gray wolf?

Answer 1

Wolves feed primarily on medium to large sized ungulates, up to the size of bovines like bison. However, like most predators, they are opportunistic feeders, and will generally eat any meat that is available,[63] including non-ungulate species,[64] carrion and garbage.[63] Cannibalism is not uncommon in wolves, and has been recorded to occur in times of food scarcity,[65] when a pack member dies,[66] and during territorial disputes.[57] Some wolf packs in Alaska and Western Canada have been observed to feed on salmon.[67][68] Humans are rarely, but occasionally preyed upon (see Attacks on humans).[35][69][70][71] Wolves will typically avoid a potential prey item which does not conform to what they experienced during their lives. Generally, the greater the discrepancy to what wolves are accustomed to, the greater their resistance to exploring it. This is only increased should the new prey act bold, assertive, and fearless. Nevertheless, even if there is no food shortage, wolves will explore alternative prey if they continually come into close contact with it and habituate themselves.[72]

lion prides, wolf packs numbering above 2 individuals show little strategic cooperation in hunting large prey.[63] Wolves typically attempt to conceal themselves as they approach their prey. Often, they will wait for the prey to graze, when it is distracted.[7] If the prey animal stands its ground or confronts the pack, the wolves will approach and threaten it. The wolves will eventually leave if their prey does not run, though the length of time can range from hours to days.[63] If their prey attempts to flee, the wolves will give chase. Wolves generally do not engage in long chases, and will usually stop a pursuit after a chase of 10-180 meters (10-200 yd), though there has been one documented case of a wolf chasing a moose for 36 kilometers (22 mi).[7] Female wolves tend to be better at chasing prey than males, while the latter are more adept at Wrestling large prey to the ground once it is caught. Packs composed largely of female wolves thrive on fleet footed prey such as elk, while packs specialising in bison tend to have a greater number of males.[73] Though commonly portrayed as targeting solely sick or infirm animals,[32] there is little evidence that they actively limit themselves to such targets. Rather, the evidence shows that wolves will simply target the easiest options available, which as well as sick and infirm animals, can also include young animals and pregnant females.[74] Though wolves commonly hunt large prey in packs, there are cases in which single wolves have successfully killed large animals unaided. One wolf was recorded to have killedmoose 11 times singlehandedly.[75]

Wolves will typically attempt to disable large prey by tearing at the haunches and perineum, causing massive bleeding and loss of coordination. A single bite can cause a wound up to 10-15 centimeters (4-6 in) in length. A large deer in optimum health generally succumbs to three bites at the perineum area after a chase of 150 meters (160 yd). Once their prey is sufficiently weakened, the wolves will grab it by the flanks and pull it down.[7] Sometimes, with medium sized prey such as dall sheep, wolves will bite the throat, severing the windpipe or jugular.[76] When attacking canid prey, such as dogs, coyotes or other wolves, wolves will kill by biting the back, neck or head.[57][77][78] With prey of equal or lesser weight to the wolf, such as lambs or small children, wolves will grab their quarry by the neck, chest, head or thigh and carry them off to a secluded spot.[7][71] Once the prey collapses, the wolves will tear open the abdominal cavity and commence feeding on the animal, sometimes before it has died.[7] On some occasions, wolves will not press an attack, and will wait for their prey to die from their wounds before feeding begins.[79]Wolves will occasionally attack pregnant ungulates to feed on the fetus(es), leaving the mother uneaten.[80] Usually, it is the dominant pair that works the hardest in killing the pack's target.[63] Wolves have on occasion been observed to engage in acts of surplus killing. This phenomenon is common when wolves target livestock.[81] In the wild, this usually occurs in late winter or spring when deep snow impedes their prey's escape.[81][82]

Pack status is reinforced during feeding. The breeding pair usually eats first, starting with the heart, liver, and lungs. Wolves of intermediate rank will prevent lower ranking pack members from feeding until the dominant pair finishes eating.[24] The stomach of prey is eaten, though the contents are left untouched if the killed animal is a herbivore. The leg muscles are eaten next, with the hide and bones being the last to be consumed.[63] If they are disturbed while feeding, they will instead focus their attention on their prey's fat deposits rather than internal organs.[83][84] A single wolf can eat up to 3.2-3.5 kilograms (7-8 lb) of food at a time, though they can eat as much as 13-15 kilograms (29-33 lb) when sufficiently hungry. A wolf's yearly requirement is 1,500 kilograms (3,307 lb).[7] Wolves can go without sustenance for long periods, with a Russian record showing how one specimen survived for 17 days without food.[4]Research has shown that 2 weeks without food will not weaken a wolf's muscle activity.[7] After eating, wolves will drink large quantities of water to prevent uremic poisoning.[4] A wolf's stomach can hold up to 7.5 liters (8 U.S. qt).[7] Wolves supplement their diet with vegetation. Scat analysis found 75% of samples found Yellowstone National Park wolves' summer diet contained plants mostly grass (Graminae).[85] In some areas of the former Soviet Union wolves have been reported to cause serious damage to watermelon plantations.[74]

Studies on how wolves affect prey populations tend to vary considerably, with some results indicating that wolves dramatically reduce, sometimes locally extirpate some prey species, while others indicate that wolf predation simply takes over from other mortality factors present in wolf-free zones.[65][82] Wolves are not essential for the presence of many other species