WOLF FOOD: DIET, HUNTING: PREY, TACTICS, FEEDING HABITS

WOLF DIET

gray wolves feeding on a white-tailed deer

Gray wolves are carnivores (eat meat or animal parts) and mostly eat terrestrial vertebrates. They hunt prey on their own, in packs, steal the prey of other predators, or scavenge carrion. Prey is located by chance or scent. Animals included in the diet of gray wolves varies geographically and depends on prey availability. [Source: Wikipedia, Tanya Dewey and Julia Smith, Animal Diversity Web (ADW) |=|]

The diet of North American wolves is dominated by wild ungulates and medium-sized mammals. The diet Asian and European wolves is dominated by wild medium-sized hoofed mammals and domestic animals. Wolves have traditionally depended on wild species, and if these are not readily available, as often the casein Asia, they are more likely to feed on domestic species. Across Eurasia, wolves prey mostly on moose, red deer, roe deer and wild boar. In North America, they prey mainly on elk, moose, caribou, white-tailed deer and mule deer. Prior to their extirpation from North America, wild horses were among the most frequently consumed prey of North American wolves.

According to Western Wildlife Outreach: “In the western United States, wolves prey primarily on deer, elk, and moose. Wolves are opportunistic feeders and will also eat smaller mammals such asbeavers and rabbits, as well as domestic livestock, dead animals, and vegetation. Coastal wolves in British Columbia are known to eat migrating salmon. Adult wolves eat 5 to 14 pounds of meat per day on average, but sometimes 12 days or more may pass between feedings... After a successful kill, wolves devour the carcass, sometimes eating as much as 20 pounds, and then may remain relatively inactive for one or more days, digesting their meal. [Source: Western Wildlife Outreach westernwildlife.org]

Wolf Feeding Habits

Wolves can go two weeks or more without eating and then gorge themselves by eating eight kilograms (20 pounds) of meat, a quarter of their weight, in one sitting. Arctic researcher David Mech once observed a pack of 15 wolves bring down a 600-pound moose and eat half the carcass in three hours.

Ethiopian wolf feeding on a rodent

Wolves often wash after making a kill and compete among one another when eating. They often eat bones, or at least the marrow from them, as well as meat. When there is too much to eat they hide the meat in caches to be retrieved later on. Enough food is saved to feed to ups. Often it is consumed and regurgitated in the mouths of the pups.

Wolves eat quickly. If they don't, ravens, vultures and small mammals like martens or foxes that appear soon on the scene will steal away a significant share of the kill. Wolves and wild dogs in Africa often began feeding on their prey before it is dead and people who have observed this find it horrifying. Wolves can crack open bones to feed on the marrow inside. Like bears, wolves will eat garbage if the have access to it.

Wolves usually utilize the entire carcass, including some hair and bones. Wolves can digest their meal in a few hours and can feed several times in one day, making quick use of large quantities of meat. A well-fed wolf stores fat under the skin, around the heart, intestines, kidneys, and bone marrow, particularly during the autumn and winter. Wolves sometimes follow ravens to dead animal. Ravens can not break open the skin of animals with a tough hide like bears so they wait for wolves to show ups and break open the skin. Ravens sometimes peck wolves that act submissive. [Source: Wikipedia, Tanya Dewey and Julia Smith, Animal Diversity Web (ADW) |=|]

Wolf Prey

Wolves feed on small rodents, mice, rabbits, lemmings, hares, ptarmigans, other nesting birds, fish, seals, wild boar, beavers, ibex, bighorn sheep, elk, deer, moose, musk oxen ad buffalo. Wolves feed on beavers when the forage for food in the early spring. They Wolves have been observed feeding on a bear carcass but they have never been seen killing a bear.

Wolves primarily hunt in packs for large prey such as moose, elk, bison, musk oxen, and reindeer. They feed predominantly on wild large hoofed mammals (ungulates) that can be divided into large ones (240–650 kilograms, 530–1,430 pounds) and medium size ones (23–130 kilograms, 51–287 pounds) and have a body mass similar to that of the combined mass of the pack members. Smaller prey such as beavers, rabbits, and other small mammals are usually hunted by lone wolves, and they are a substantial part of their diet. Wolves may also eat livestock and garbage when it is available.[Source: Wikipedia, Tanya Dewey and Julia Smith, Animal Diversity Web (ADW) |=|]

Wolves follow he scents and track their prey but more often that not it seems they come across prey in chance encounters they come across when roaming their territories. They availability of prey is often main determining factor determining whether wolves will survive or not in a given area.

According to Western Wildlife Outreach: Wolf kills can be differentiated from other predator kills by studying prey remains. Wolves typically attack the hindquarters, flanks, shoulders, nose, and tail of their prey. They feed preferentially on the viscera and hind limbs. The feeding strategy is not obvious if the animal is attacked by a pack, as the carcass is usually quickly consumed. Wolf tracks, hair and scat can often be found near a wolf kill. [Source: Western Wildlife Outreach westernwildlife.org ]

The size of wolf population is often determined by the number of animals they can feed on. Wolves in the Arctic survive the winter perhaps by scavenging carcasses of animals like musk oxen that haven't survived the winter. In other cold regions, winter is often the best hunting time. Perhaps the wolves greatest skill is appraising victims that it is most likely to kill: Their preferred targets are the young, infirm, elderly or crippled.

Wolves as Hunters

Wolves specialize on preying on the vulnerable individuals of large prey, with a pack of 15 able to bring down an adult moose. Once these large ungulates are taken down, the wolves attack their rump, flank, and shoulder areas. Wolves control prey populations by hunting the weak, old, and immature. A wolf can consume up to nine kilograms of meat at one meal. The variation in diet between wolves living on different continents is based on the variety of hoofed mammals and of available smaller and domesticated prey.

Their strength, intelligence, and coordinated pack behavior makes wolves very successful predators. On average each wolf takes an average of 18 to 20 deer a year. Still wolves live a feast and famine existence and can go two weeks or more without food. They are also notorious raiders, stealing food from human camps whenever they get the chance.

The success rate of wolf chases is only three to 14 percent. "Wolves fail as hunters more often than they succeed," Stevens wrote in the New York Times, "Their main prey species have evolved with them, and so developed formidable defenses. Wolves appear to respect sharp hooves, horns and antlers so much that a moose, elk, deer that stands will likely discourage the predators from attacking. And unless the wolves catch their prey early in a chase, an ungulate easily outruns them.”

Wolves hunt in packs, roaming single file at pace of about five miles an hour for hours and hours in search of prey. They often travel 45 miles a day, behavior summed up by the Russian proverb, "The wolf is kept feed by its feet.” Wolves strike their prey at angles and try to separate weak members from the group and take turns nipping at their prey until it is exhausted and vulnerable. There used to be reports that wolves hamstrung their victims but thus far biologists who have studied hundreds of kills have never seen a severed Achilles tendon.

Wild dogs and wolves are not very good sprinters. They have great endurance and capture their prey by relentlessly pursuing them and doggedly wearing them down. Wolves usually attack from behind and the sides, with experienced wolves usually taking the lead, feinting and attacking from opposite sides until a crippling bite or slash can be made to leg muscles that slows and brings the prey down for a killing or incapacitating bite to the throat.

Wolf Attacks on Elk and Moose

For protection against wolves, animals like deer and elk group together, seeking safety in numbers. Describing a wolf attack on a herd of elk, Douglas Chadwick wrote in National Geographic, "The wolf pack before us moved from on elk band to the next, taking their measure. Sometimes the elk outran the wolves. One bull elk whirled so fast on a pursuer that a loose antler flew right off his head. Other drew together and stood their ground, warding off incursions with violent kicks."

"As an elk foreleg could easily smash ribs or dent a skull, the wolves tried bluff rushes, looking to cause a band member to panic and bolt. We could sense a battle momentum seesawing second by second, the outcome never preordained but rather a summation of each animal's skill, determination, and experience, plus a little old fashioned luck...One morning I watched a n elk disappear over the brow of a ridge with a wolf hanging on each shoulder. Three minutes later it reappeared—seemingly uninjured—and was soon grazing while the wolf pair loped off."

Describing an attack on a moose and calf, Mech wrote in National Geographic: "Most of the wolves were worrying the cow while two pursued its bolting offspring. After about 150 yards, one wolf lunged at the rump of the calf and held on: the other clamped onto its throat. The calf stopped and began trampling the front wolf into the snow. Still the wolf managed to hold one before relinquishing its throat hold." [Source: David Mech, National Geographic, October 1977]

"The other wolf, however remained tugging on the calf's rump. The front wolf then dived under the running moose and again fastened onto its throat...Then two more wolves reinforced the attack. One grasped the calf by the nose, and other by its right flank. The struggling moose pulled all four wolves through the snow, then finally collapsed in a heap. A few minutes later the moose's flesh was being converted into wolf's meat."

Wolves and Moose at Isle Royale, Michigan

The wolves and moose at Isle Royale, Michigan are the subjects of world’s longest-running study of predators and prey. T.A. Frail wrote in Smithsonian Magazine: First came the moose. About 100 years ago, some of the animals swam or walked across ice to Isle Royale, a fir- and spruce-covered island in Lake Superior. There they found moose heaven, nothing but forage. Next came the gray wolves. They arrived around 1950, after a cold winter allowed them to cross 15 miles of ice from the Canadian shore. They found a wolf idyll, all moose meat and a dearth of people, who had wiped out most of the wolves everywhere in the United States except Alaska. Last came the wildlife biologists, in 1958. They wanted only to watch nature take its course. Other people had preceded the scientists — Isle Royale had been a resort in the early 20th century and part of a national park since 1940 — but the biologists found their own kind of idyll, full of data to glean from a natural experiment in evolutionary biology. [Source:T.A. Frail, Smithsonian Magazine, January 2012]

The moose, the wolves and the biologists are still at Isle Royale National Park, collaborating. Islands, as Charles Darwin discovered in the Galápagos, make good laboratories for studying evolution. For one thing, they have discrete ecosystems, which present fewer variables to sort out — fewer species, fewer individuals, fewer interrelationships.

Researchers from what is formally known as the Isle Royale Wolf-Moose Study have made fundamental observations of how this particular pairing of predator and prey has evolved in response to each other. Rolf Peterson, who has been with the study since 1970, has noted that while a wolf pack is an impressive killing machine, an adult moose does not go gently into that good night: “An old forest with lots of downed trees also allows a moose to ‘comb’ the wolves from its backside by running or twirling around and violently throwing them against trees,” he wrote in The Wolves of Isle Royale: A Broken Balance. “This behavior helps explain the broken ribs often found in the skeletons of old wolves on Isle Royale.”

John Vucetich, who leads the study with Peterson, has data suggesting that as the wolves have preyed on smaller moose — which are easier to bring down — they have influenced moose evolution. With big moose surviving and breeding, they tended to produce offspring that grew into big adults, meaning that the size of the average member of the herd increased. That effect might seem logical, but the Isle Royale research may be the first to document the phenomenon in a predator-prey pair in the wild. Beyond that, the study has determined that even in a simple ecosystem, the predator-prey relationship is complex. “The number of factors that determine the annual outcome of wolf-moose interaction is truly baffling,” Peterson says. The wolves have ranged in number from 12 to 50, and the moose from 385 to 2,422 — and those numbers have not always risen and fallen in tandem. Plant life, weather and disease dramatically affect both populations.

For example, from the peak of 50, reached in 1980, the wolf population crashed to 14 by 1982, despite a relatively stable population of moose. The cause turned out to be canine parvovirus, which came to the island via a dog. The moose numbers rose steadily while the wolf numbers recovered, hitting that peak of 2,422, in 1995. Then more than half of the moose starved during the bitter winter of 1995-96.

More recently, warmer weather has led to higher numbers of moose ticks, which led to weaker moose, which led to easier kills for wolves. Meanwhile, the wolves have shown a high incidence of a backbone malformation from inbreeding. In 2010, the study determined that a new alpha male had migrated to Isle Royale in 1997, which might have refreshed the gene pool if he hadn’t initiated a genetic sweep of his own by breeding so prolifically with the local females. As of 2007, all Isle Royale wolves are related to him. The most recent concern, Vucetich says, is a dearth of females: There are now no more than two left on the island.

Impact of the Wolves on Moose on Isle Royale

According to the study in Frontiers in Ecology and Evolution, the moose on Isle Royale appear to need wolves to keep their populations healthy from disease. Before the wolves arrived on Isle Royale Doug Smith, a wildlife biologist who worked on the island told NBC News, “The moose eat themselves out of house and home, literally, and then they have a massive die-off. They crash, and then it starts all over again. “By keeping wolves in Isle Royale, you keep the moose population in check, which means they don’t eat the whole forest up,” Smith said. “Without a predator, they repeat the whole cycle.” [Source: Evan Bush, NBC News, April 23, 2022]

Evan Bush of NBC News wrote:In the recent Frontiers study, researchers evaluated the bones of moose killed by wolves over a 32-year period from 1975 to 2007. More than 38 percent of the 1,572 moose skeletons they examined had signs of osteoarthritis. Analysis of wolf kills suggests they preyed more frequently on old moose. Wolves didn’t appear to target moose in their prime ages, unless the moose were affected by severe arthritis, the study found. Rates of arthritis in moose grew during years with lower kill rates from wolves, the research says.

To kill a moose, a wolf must attack an animal about 10 times its size with only its teeth, so it makes sense that wolves would succeed in taking down those unable to move well, biologist Sarah Hoy said. The study hints that wolves could play an important role in controlling genetic diseases by removing unhealthy animals from the population. It follows similar research in deer, which show wolves can help dampen the impacts of easily spread infections like chronic wasting disease. “This is a good example of how the predator is actually helping the moose population,” said William Ripple, a professor and ecologist at Oregon State University, who was not involved in the research. “The wolves don’t just randomly take prey. It just so happens they will take more prey that are diseased than by chance, and that has strong evolutionary implications for natural selection.”

Diseases, tick outbreaks and severe winters have driven some population trends. But in recent years climate change made an impact so significant that the U.S. government decided to step in. Ice bridges to the island once formed seven years out of 10. Today, these bridges form just once or twice during the same time span, Smith said. And in recent years, the wolf population dwindled to just two — a severely inbred pair who were both father and daughter and brother and sister, according to Hoy. They couldn’t produce pups that would survive. “It was clear why the wolf population crashed. It was because of the loss of the ice bridge. They no longer had connectivity,” Smith said. “Genetic depression.” The moose population began to skyrocket. The U.S. Fish and Wildlife Service began a project in the fall of 2018 to relocate wolves to the island to provide genetic diversity.

Wolves Hunting Bison

David Attenborough wrote : The bison is the biggest animal in North America. A bull can weigh nearly a ton. It is immensely strong. A blow from its horns could crack a skull. A kick from its legs could break a spine. But in the winter, hunger drives wolvers in the northern part of the continent to attack bison

“The grey wolf that lives here is the biggest of all dogs. Such great size is what you might expect since a big animal retains its heat more successfully than a small one. It stands over three feet tall at the shoulder and is over six feet from its nose to end of its tail. It is almost twice as big as an Alsatian. But even so, there is no way in which a single dog even of this size could bring down an adult bison. Grey wolves can only do it working as a team. [Source: “Life of Mammals” by David Attenborough]

“The scrubland and open prairie where bison graze has little cover. If a group of wolves get close to a group of them, the bison gather together, facing outwards, with their small vulnerable calves at the center. But they cannot stay in such a formation forever. They have to disperse to feed, If the wolves find one somewhat away from the main herd, they might alarm it sufficiently to make a run to join the rest. If others look up from their grazing, they too may gallop away. the wolves have a chance.

The pack gives chase. There may twenty or thirty of them. The pursuit may last on and off for days, during which the herd followed by the pack, will travel many miles. The wolves are testing the bison, trying to identify one that may be less strong because of age of sickness. It is likely to be one of those lagging behind. Gradually the pack focus their attention on a particular individual and run in a group behind it, snapping at its heels.

“Their claws are not sharp enough to give them a hold in the bison’s flanks. All they can do is try to get a grip with their teeth. These are their only weapons. If one does succeed, it may slow the bison sufficiently for other to get a hold as well. The bison may manage to shake them off, but the wolves are persistent. It may be half an hour before their victim is weakened enough for them to surround it, Now, with the wolves threatening it faces one; others get hold of the underbelly. Eventually they bring it down. They rip at its stomach, disemboweling it. But there is no way they can kill a bison quickly. So they feed on it. Tearing at its flesh, ripping out its entrails while it is still alive. There will enough food on a single bison to last the wolf pack, if necessary, for a week.

Wolf Attack on Caribou

Wolves are the main natural predators of reindeer and caribou. Historically they have fed on the weak, old and infirm and helped the reindeer population by ensuring the strongest produced offspring and the herd as whole didn't overgraze the land. With most of the wolves in Scandinavia now gone the primary controlling agent of the reindeer herds are the Lapps and other reindeer herders.

Describing an unsuccessful attack by a wolf on a herd of caribou, Mech wrote in National Geographic,"The herd, sensing the wolf, was drown together as is by some giant biological magnet. The tightly pressed group flowed quickly forward...The white wolf made its decision. Instantly it sprang forward. While stragglers gravitated toward the herd, the wolf began closing the 200-yard gap."

"As the wolf pressed close, the caribous increased their speed. Straight toward them the white wolf sped, with legs alternately stretching out then pulling together in 15-foot bounds...The chase covered a quarter of a mile, and the wolf tried its best. Still the hunter was unable to come closer than about 200 feet of its intended prey...Less than a minute after the chase had begun, it was over."

Wolf Attack on a Musk Ox

Describing an attack of three musk ox calves with eleven 500-pound adults, David Mech wrote in National Geographic, "The musk-oxen bunched together in a semicircle, hindquarters pressed together, protecting the calves. A long standoff deteriorated as a single ox broke ranks, and the heard scattered in small groups that grew increasingly nervous while wolves darted among them, They skirmished until finally the whole herd panicked and fled into a cloud of dust, with the wolves in hot pursuit.

"One wolf tests the group, trying to separate the calf from the adults, Protecting their calves a group of oxen try to reorganize but to no avail. Soon the alpha male wolf puts on a burst of speed and grabs the first calf. Within a few furious moments the pack had caught and killed all three calves, including one that stirs competition among the predators."

“One calf was dispatched by a bite to the head by one wolf and a bite over the nose by another wolf, with the other members dragging the poor animal down. Once it was subdued members of the pack took off after a second calf and brought it down while it was crossing a creek. Once it was under control, wolves took after the third calf and killed it. The adult oxen were too confused and directed by herding behavior to save the calves.”

Ecological Roles of Wolves

Large predators like wolves and cougars play an important role in maintaining the health of natural ecosystems. Wolves prey primarily on animals that are young or elderly, sick or injured, and weak or unfit, thus keep prey populations healthy.. Wolf kills create an abundant and dependable food source for many other species. Researchers have documented wolf kills benefiting coyotes, bald eagles, golden eagles, grizzly bears, black bears, ravens, magpies, red foxes and at least 20 other species. By preventing large herbivores, such as deer and elk, from becoming overpopulated wolves help maintain native biodiversity. Deer and elk can overgraze their habitat when populations outgrow the carrying capacity of an ecosystem. Overgrazing destroys the plant base, making the habitat less suitable for other species. When gray wolves were reintroduced into Yellowstone National Park in1995 after a 70-year absence, they began to restore ecosystems that had been degraded in their absence.” *** [Source: Western Wildlife Outreach westernwildlife.org ***]

In 1995 and 1996, 66 wolves trapped in Canada were released in Yellowstone and the Idaho wilderness, by 2010 they had generated more than 1,700 wolves that lived in more than 200 wolf packs. Chip Ward wrote in Los Angeles Times: When we exterminated wolves from Yellowstone in the early 1900s, we de-watered the land. That’s right; no wolves eventually meant fewer streams, creeks, marshes and springs across western landscapes like Yellowstone where wolves had once thrived. The chain of effects went roughly like this: No wolves meant that many more elk crowded onto inviting river and stream banks. A growing population of fat elk, in no danger of being turned into prey, gnawed down willow and aspen seedlings before they could mature. As the willows declined, so did beavers, which used the trees for food and building material. When beavers build dams and make ponds, they create wetland habitats for countless bugs, amphibians, fish, birds and plants, as well as slowing the flow of water and distributing it over broad areas. The consequences of their decline rippled across the land. Meanwhile, as the land dried up, Yellowstone’s overgrazed riverbanks eroded. Spawning beds for fish silted over. Amphibians lost precious shade. Yellowstone’s web of life was fraying.[Source: Chip Ward, Los Angeles Times, October 5, 2010]

The decision to put wolves back in Yellowstone was a bold experiment backed by the best conservation science available to restore a cherished American ecosystem that was coming apart at the seams. The unexpected relationship between absent wolves and absent water is just one example of how large predators such as grizzlies, wolves and mountain lions regulate their ecosystems from the top down. The results are especially relevant in an era of historic droughts and global warming, both of which are stressing already arid Western lands.

At the time wolves were reintroduced, Yellowstone had just one beaver colony. Today, 12 colonies are busy storing water, evening out seasonal water flows, recharging springs and creating habitat. Willow stands are robust again, and the songbirds that nest in them are recovering. Ravens, eagles, wolverines and bears, which scavenge wolf kills for meat, have benefited. Wolves have pushed out the coyotes that feed on pronghorn antelope, so pronghorn numbers are also up. Riverbanks are lush and shady again. With less competition from elk for grass, the bison in the park are doing better too.

That is not to say there were no losers. Elk numbers have been diminished — but that, after all, was one purpose of reintroducing wolves. The elk population of Yellowstone is still larger than at its low point in the late 1960s, but there are fewer elk today than in recent decades. Still, the decline has alarmed elk hunters — and the local businesses that rely on their trade. Worse yet, from the hunting point of view, elk behavior has changed dramatically. Instead of camping out on stream banks and overeating, they roam far more and in smaller numbers, browsing in brushy areas with more protective cover. Surviving elk are healthier but leaner, warier, far more dispersed and significantly harder to hunt. This further dismays those who had become accustomed to easy hunting and bigger animals.

Never Cry Wolf Myth

Wolves strengthen the gene pool of their prey by weeding out the old, sick and weak. They provide scavengers with a supply of carrion, especially during the winter when they need it most. By limiting the size of large herds of hoofed animal, wolves also make sure there is forage and vegetation to feed on.

According to Western Wildlife Outreach: Wolves play a critical role in healthy, dynamic ecosystems, and recent studies have shown that their activities can help mitigate the potential impacts of climate change. They keep ungulate herds strong by culling sick individuals, they allow plant diversity to increase by keeping grazers like elk on the move (called the “ecology of fear”), and the carcasses from their kills support other wildlife such as bald eagles, coyotes, bears and foxes. By protecting large, connected tracts of wild lands, we can be sure that wolves will have the space they need to provide these important ecosystem services without coming into conflict with people. [Source: Western Wildlife Outreach westernwildlife.org ]

But it is somewhat of a myth that the health of deer populations depend on wolves to cull weak and diseased animals. Studies show that the size and health of deer population is related to snow depth, cold and the availability of food, not wolves. One biologist told National Geographic, "Our data shows that wolves take mainly the youngest deer—those less than a year of age. Old, weak animals are the second most common targets...The herds can handle it" because deer reproduce a lot.

Image Sources: Wikimedia Commons

Text Sources: Animal Diversity Web animaldiversity.org ; National Geographic, Live Science, Natural History magazine, David Attenborough books, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Discover magazine, The New Yorker, Time, BBC, CNN, Reuters, Associated Press, AFP, Lonely Planet Guides, Wikipedia, The Guardian, Top Secret Animal Attack Files website and various books and other publications.

Last updated May 2025