Wolf

This article is about the gray wolf, Canis lupus, and its subspecies. For other species of wolf and other uses, see Wolf (disambiguation).

"Gray Wolf" and "Grey Wolf" redirect here. For other uses, see Gray Wolf (disambiguation).

Gray wolf Temporal range: Middle Pleistocene – present (810,000–0 years BP)
Eurasian wolf (Canis lupus lupus).
Conservation status
Least Concern  (IUCN 3.1)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Canidae
Genus:	Canis
Species:	C. lupus
Binomial name
Canis lupus Linnaeus, 1758
Subspecies
refer Subspecies of Canis lupus
Historical (red + green) and modern (green) range of wild subspecies of C. lupus

The wolf (Canis lupus), also known as the gray/grey wolf, timber wolf, or tundra wolf, is a canine native to the wilderness and remote areas of Eurasia and North America. It is the largest extant member of its family, with males averaging 43–45 kg (95–99 lb) and females 36–38.5 kg (79–85 lb). It is distinguished from other Canis species by its larger size and less pointed features, particularly on the ears and muzzle. Its winter fur is long and bushy and predominantly a mottled gray in color, although nearly pure white, red and brown to black also occur. Mammal Species of the World (3rd ed., 2005), a standard reference work in zoology, recognises 38 subspecies of C. lupus.

The gray wolf is the second most specialized member of the genus Canis, after the Ethiopian wolf, as demonstrated by its morphological adaptations to hunting large prey, its more gregarious nature, and its highly advanced expressive behavior. It is nonetheless closely related enough to smaller Canis species, such as the coyote and golden jackal, to produce fertile hybrids. It is the only species of Canis to have a range encompassing both Eurasia and North America, and originated in Eurasia during the Pleistocene, colonizing North America on at least three separate occasions during the Rancholabrean. It is a social animal, travelling in nuclear families consisting of a mated pair, accompanied by the pair's adult offspring. The gray wolf is typically an apex predator throughout its range, with only humans and tigers posing a serious threat to it. It feeds primarily on large ungulates, though it also eats smaller animals, livestock, carrion, and garbage. A seven-year-old wolf is considered to be relatively old, and the maximum lifespan is about 16 years.

The global gray wolf population is estimated to be 300,000. The gray wolf is one of the world's best-known and most-researched animals, with probably more books written about it than any other wild species. It has a long history of association with humans, having been despised and hunted in most pastoral communities because of its attacks on livestock, while conversely being respected in some agrarian and hunter-gatherer societies. Although the fear of wolves is pervasive in many human societies, the majority of recorded attacks on people have been attributed to animals suffering from rabies. Non-rabid wolves have attacked and killed people, mainly children, but this is rare, as wolves are relatively few, live away from people, and have developed a fear of humans from hunters and shepherds.

Taxonomy

The species Canis lupus was named by the Swedish botanist and zoologist Carl Linnaeus in his publication Systema Naturae in 1758, The nominate subspecies is the Eurasian wolf (Canis lupus lupus), based on the type specimen from Sweden. The thirty-eight subspecies of Canis lupus are listed under the designated common name of "wolf" in Mammal Species of the World (3rd edition) that was published in 2005. The domestic dog is listed as subspecies, and the dingo with the New Guinea singing dog form another subspecies.

Evolution

Main article: Evolution of the wolf

Artist's impression of a Beringian wolf

The evolution of the wolf occurred over a geologic time scale of at least 300,000 years. The gray wolf (Canis lupus) is a highly adaptable species that is able to exist in a range of environments and which possesses a wide distribution across the Holarctic. Studies of modern gray wolves have identified distinct sub-populations that live in close proximity to each other. This variation in sub-populations is closely linked to differences in habitat – precipitation, temperature, vegetation, and prey specialization – which affect cranio-dental plasticity.

The archaeological and paleontological records show gray wolf continuous presence for at least the last 300,000 years. This continuous presence contrasts with genomic analyses, which suggest that all modern wolves and dogs descend from a common ancestral wolf population that existed as recently as 20,000 years ago. These analyses indicate a population bottleneck, followed by a rapid radiation from an ancestral population at a time during, or just after, the Last Glacial Maximum. However, the geographic origin of this radiation is not known.

In 2018, whole genome sequencing was used to compare members of the genus Canis, along with the dhole (Cuon alpinus) and the African wild dog (Lycaon pictus). There is evidence of gene flow between African golden wolves, golden jackals, and gray wolves. One African golden wolf from the Egyptian Sinai Peninsula showed high admixture with the Middle Eastern gray wolves and dogs, highlighting the role of the land bridge between the African and Eurasian continents in canid evolution. There was evidence of gene flow between golden jackals and Middle Eastern wolves, less so with European and Asian wolves, and least with North American wolves. The study proposes that the golden jackal ancestry found in North American wolves may have occurred before the divergence of the Eurasian and North American gray wolves. The study indicates that the common ancestor of the coyote and gray wolf has genetically admixed with a ghost population of an extinct unidentified canid. The canid was genetically close to the dhole and had evolved after the divergence of the African wild dog from the other canid species. The basal position of the coyote compared to the wolf is proposed to be due to the coyote retaining more of the mitochondrial genome of this unknown canid.

Hybridization with other Canis

Main article: Canid hybrid

F₁ wolf-dog hybrids from Wildlife Park Kadzidlowo, Poland. The first is the product of a male wolf and a female spaniel, while the latter comes from a female wolf and a male West Siberian Laika.

It was once thought that domestic dogs and gray wolves did not voluntarily interbreed in the wild, though they can produce fertile wolf-dog offspring. In 2010, a study of 74 Italian wolf male lineages found that five of them originated from dog ancestry, indicating that female wolves will breed with stray male dogs in the wild. In North America, black-colored wolves acquired their coloration from wolf-dog hybridization, which occurred 10,000–15,000 years ago. Similar to pure wolves, hybrids breed once annually although their mating season occurs three months earlier, with pups mostly being born in the winter period and therefore lessening their chances of survival. However, one genetic study undertaken in the Caucasus Mountains showed that as many as 10% of dogs in the area, including livestock guardian dogs, are first generation hybrids. The captive breeding of wolf-dog hybrids has proliferated in the United States, where there is an estimated population of 300,000.

The gray wolf does not readily interbreed with coyotes. Nevertheless, In 2018, a study looked at the genomic structure and admixture of North American wolves, coyotes, and other wolf-like canids using specimens from across their entire range that mapped the largest dataset of nuclear genome sequences and compared these against the wolf reference genome. The study supports the findings of previous studies that North American gray wolves and other wolf-like canids were the result of complex gray wolf and coyote mixing. A polar wolf from Greenland and a coyote from Mexico represented the purest specimens. The coyotes from Alaska, California, Alabama, and Quebec show almost no wolf ancestry. Coyotes from Missouri, Illinois, and Florida exhibit 5–10% wolf ancestry. There was 40%:60% wolf to coyote ancestry in red wolves, 60%:40% in eastern wolves from Ontario, and 75%:25% in wolves in the Great Lakes region. There was 10% coyote ancestry in Mexican wolves, 5% in Pacific Coast and Yellowstone wolves, and less than 3% in Canadian archipelago wolves. The study indicates that the genomic ancestry of red, eastern and Great Lakes wolves were the result of admixture between modern gray wolves and modern coyotes. This was then followed by development into local populations. Individuals within each group showed consistent levels of coyote to wolf inheritance, indicating that this was the result of relatively ancient admixture. The eastern wolf (Angonquin Provincial Park) is genetically closely related to the Great Lakes wolf (Minnesota, Isle Royale National Park). If a third canid had been involved in the admixture of the North American wolf-like canids, then its genetic signature would have been found in coyotes and wolves, which it has not.

Additionally, coyote genetic markers have been found in some wild isolated gray wolf populations in the southern United States. Gray wolf Y-chromosomes have also been found in Texan coyote haplotypes. In tests performed on a Texan canid of ambiguous species, mtDNA analysis showed that it was a coyote, though subsequent tests revealed that it was a coyote–gray wolf hybrid sired by a male Mexican wolf. In 2013, a captive breeding experiment in Utah between gray wolves and western coyotes produced six hybrids through artificial insemination, making this the first hybridization case between pure coyotes and northwestern wolves. At six months of age, the hybrids were closely monitored and were shown to display both physical and behavioral characteristics from both species.

Although hybridization between wolves and golden jackals has never been observed, evidence of such occurrences was discovered through mtDNA analysis on jackals in Bulgaria. Although there is no genetic evidence of wolf-jackal hybridization in the Caucasus Mountains, there have been cases where otherwise genetically pure golden jackals have displayed remarkably gray wolf-like phenotypes, to the point of being mistaken for wolves by trained biologists.

Population structure

In 2013, a genetic study found that the wolf population in Europe was divided along a north-south axis and formed five major clusters. Three clusters were identified occupying southern and central Europe in Italy, the Dinaric-Balkans, the Carpathians. Another two clusters were identified occupying north-central Europe and the Ukrainian steppe. The Italian wolf consisted of an isolated population with low genetic diversity. Wolves from Croatia, Bulgaria, and Greece formed the Dinaric-Balkans cluster. Wolves from Finland, Latvia, Belarus, Poland and Russia formed the north-central Europe cluster, with wolves from the Carpathians cluster coming from a mixture of wolves from the north-central cluster and the Dinaric-Balkans cluster. The wolves from the Carpathians were more similar to the wolves from the Pontic-Caspian Steppe than they were to wolves from north-central Europe. These clusters may have been the result of expansion from glacial refugia, an adaptation to local environments, and landscape fragmentation and the killing of wolves in some areas by humans.

In 2016, two genetic studies of North American gray wolves found that they formed six ecotypes – genetically and ecologically distinct populations separated from other populations by their different type of habitat. These six wolf ecotypes were named West Forest, Boreal Forest, Arctic, High Arctic, Baffin, and British Columbia. The studies found that precipitation and mean diurnal temperature range were the most influential variables. These findings were in accord with previous studies that precipitation influenced morphology and that vegetation and habitat type influenced wolf differences. The local adaptation of a wolf ecotype most likely reflects a wolf's preference to remain in the type of habitat that it was born into.

Description

Anatomy and dimensions

See also: Dog anatomy

Differences between gray wolf and coyote

Gray wolf skeleton

Wolf mandible diagram showing the names and positions of the teeth.

The gray wolf is the largest extant member of the Canidae, excepting certain large breeds of domestic dog. Gray wolf weight and size can vary greatly worldwide, tending to increase proportionally with latitude as predicted by Bergmann's rule, with the large wolves of Alaska and Canada sometimes weighing 3–6 times more than their Middle Eastern and South Asian cousins. On average, adult wolves measure 105–160 cm (41–63 in) in length and 80–85 cm (31–33 in) in shoulder height. The tail measures 29–50 cm (11–20 in) in length. The ears are 90–110 mm (3.5–4.3 in) in height, and the hind feet are 220–250 mm (8.7–9.8 in). The mean body mass of the extant gray wolf is 40 kg (88 lb), with the smallest specimen recorded at 12 kg (26 lb) and the largest at 79.4 kg (175 lb). Gray wolf weight varies geographically; on average, European wolves may weigh 38.5 kg (85 lb), North American wolves 36 kg (79 lb) and Indian and Arabian wolves 25 kg (55 lb). Females in any given wolf population typically weigh 5–10 lb (2.3–4.5 kg) less than males. Wolves weighing over 54 kg (119 lb) are uncommon, though exceptionally large individuals have been recorded in Alaska, Canada, and the forests of western Russia. The heaviest recorded gray wolf in North America was killed on 70 Mile River in east-central Alaska on July 12, 1939 and weighed 79.4 kg (175 lb).

Compared to its closest wild cousins the coyote and the golden jackal, the gray wolf is larger and heavier, with a broader snout, shorter ears, a shorter torso and a longer tail. It is a slender, powerfully built animal with a large, deeply descending rib cage, a sloping back and a heavily muscled neck. The wolf's legs are moderately longer than those of other canids, which enables the animal to move swiftly, and allows it to overcome the deep snow that covers most of its geographical range. The ears are relatively small and triangular. Females tend to have narrower muzzles and foreheads, thinner necks, slightly shorter legs and less massive shoulders than males.

The gray wolf usually carries its head at the same level as the back, raising it only when alert. It usually travels at a loping pace, placing its paws one directly in front of the other. This gait can be maintained for hours at a rate of 8–9 km/h (5.0–5.6 mph), and allows the wolf to cover great distances. On bare paths, a wolf can quickly achieve speeds of 50–60 km/h (31–37 mph). The gray wolf has a running gait of 55–70 km/h (34–43 mph), can leap 5 m (16 ft) horizontally in a single bound, and can maintain rapid pursuit for at least 20 minutes.

Generally, wolves have a high heart weight of 0.93%–1.07% total body mass compared to the average mammal at 0.59% total body mass. Wolves have a decreased heart rate suggesting cardiac enlargement and hypertrophy. Tibetan wolves, which occupy territories up to 3,000 above sea level, have evolved hearts that withstand the low oxygen levels. Specifically, these wolves have a strong selection for RYR2, a gene that initiates cardiac excitation.

Skull and dentition

The gray wolf's head is large and heavy, with a wide forehead, strong jaws and a long, blunt muzzle. The skull averages 230–280 mm (9.1–11.0 in) in length, and 130–150 mm (5.1–5.9 in) wide. The teeth are heavy and large, being better suited to crushing bone than those of other extant canids, though not as specialised as those found in hyenas. Its molars have a flat chewing surface, but not to the same extent as the coyote, whose diet contains more vegetable matter. The gray wolf's jaws can exert a crushing pressure of perhaps 10,340 kPa (1,500 psi) compared to 5,200 kPa (750 psi) for a German Shepherd Dog. This force is sufficient to break open most bones. A study of the estimated bite force at the canine teeth of a large sample of living and fossil mammalian predators when adjusted for the body mass found that for placental mammals, the bite force at the canines (in Newtons/kilogram of body weight) was greatest in the extinct dire wolf (163), then followed among the extant canids by the four hypercarnivores that often prey on animals larger than themselves: the African wild dog (142), the gray wolf (136), the dhole (112), and the dingo (108). A similar trend was found with the carnassial tooth bite force, but with the extinct dire wolf and gray wolf both measuring (141), then followed by the African wild dog (136), the dhole (114), and the dingo (113).

Fur

Black- and white-colored northwestern wolves

The gray wolf has very dense and fluffy winter fur, with short underfur and long, coarse guard hairs. Most of the underfur and some of the guard hairs are shed in the spring and grow back in the autumn period. The longest hairs occur on the back, particularly on the front quarters and neck. Especially long hairs are on the shoulders, and almost form a crest on the upper part of the neck. The hairs on the cheeks are elongated and form tufts. The ears are covered in short hairs, which strongly project from the fur. Short, elastic and closely adjacent hairs are present on the limbs from the elbows down to the calcaneal tendons. The winter fur is highly resistant to cold; wolves in northern climates can rest comfortably in open areas at −40° by placing their muzzles between the rear legs and covering their faces with their tail. Wolf fur provides better insulation than dog fur, and does not collect ice when warm breath is condensed against it. In warm climates, the fur is coarser and scarcer than in northern wolves. Female wolves tend to have smoother furred limbs than males, and generally develop the smoothest overall coats as they age. Older wolves generally have more white hairs in the tip of the tail, along the nose and on the forehead. The winter fur is retained longest in lactating females, though with some hair loss around their nipples. Hair length on the middle of the back is 60–70 mm (2.4–2.8 in). Hair length of the guard hairs on the shoulders generally does not exceed 90 mm (3.5 in), but can reach 110–130 mm (4.3–5.1 in).

Coat color ranges from almost pure white through various shades of blond, cream and ochre to grays, browns and blacks, with variation in fur color tending to increase in higher latitudes. Differences in coat color between sexes are largely absent, though females may have redder tones. Black-colored wolves in North America inherited the K^b allele responsible for melanism from past interbreeding with dogs, while the mutation was found to be naturally occurring in wolves from Iran. Black specimens are more common in North America than in Eurasia, with about half the wolves in Yellowstone National Park being black.

Adaptations

Distribution

Further information: Wolf distribution

Eurasian wolf in Bavarian Forest National Park, Germany

Originally, wolf distribution occurred across Eurasia above the 12th parallel north and across North America above the 15th parallel north. However, deliberate human persecution has reduced the species' range to about one-third, because of livestock predation and fear of attacks on humans. The species is now extirpated (made locally extinct) in much of Western Europe, in Mexico and much of the United States. In modern times, the gray wolf occurs mostly in wilderness and remote areas, particularly in Canada, Alaska and the northern U.S., Europe and Asia from about 75°N to 12°N. Wolf population declines have been arrested since the 1970s, and have fostered recolonization and reintroduction in parts of its former range, due to legal protection, changes in land-use and rural human population shifts to cities. Competition with humans for livestock and game species, concerns over the danger posed by wolves to people, and habitat fragmentation pose a continued threat to the species. Despite these threats, because of the gray wolf's relatively widespread range and stable population, it is classified as Least Concern on the IUCN Red List.

Habitat

The gray wolf is a habitat generalist, and can live in deserts, grasslands, forests and Arctic tundras. Habitat use by gray wolves is strongly correlated with the abundance of prey, snow conditions, absence or low livestock densities, road densities, human presence and topography. In cold climates, the gray wolf can reduce the flow of blood near its skin to conserve body heat. The warmth of the footpads is regulated independently of the rest of the body, and is maintained at just above tissue-freezing point where the pads come in contact with ice and snow. Gray wolves use different places for their diurnal rest: places with cover are preferred during cold, damp and windy weather, while wolves in dry, calm and warm weather readily rest in the open. During the autumn-spring period, when wolves are more active, they willingly lie out in the open, whatever their location. Actual dens are usually constructed for pups during the summer period. When building dens, females make use of natural shelters such as fissures in rocks, cliffs overhanging riverbanks and holes thickly covered by vegetation. Sometimes, the den is the appropriated burrow of smaller animals such as foxes, badgers or marmots. An appropriated den is often widened and partly remade. On rare occasions, female wolves dig burrows themselves, which are usually small and short with one to three openings. The den is usually constructed not more than 500 m (550 yd) away from a water source, and typically faces southwards, thus ensuring enough sunlight exposure, keeping the denning area relatively snow free. Resting places, play areas for the pups and food remains are commonly found around wolf dens. The odour of urine and rotting food emanating from the denning area often attracts scavenging birds such as magpies and ravens. As there are few convenient places for burrows, wolf dens are usually occupied by animals of the same family. Though they mostly avoid areas within human sight, wolves have been known to nest near domiciles, paved roads and railways.

Diet

Gray wolf carrying caribou hindquarter, Denali National Park

Globally, gray wolf diet is predominantly composed of large (240–650 kg (530–1,430 lb)) and medium-sized (23–130 kg (51–287 lb)) wild ungulates, with local population variations due to the mix of wild ungulates, smaller prey and domestic species consumed. All terrestrial mammalian social predators feed predominantly on terrestrial herbivorous mammals that have a body mass similar to that of the combined mass of the social group members. The gray wolf generally specializes in preying on the vulnerable individuals of large prey, with pack of timber wolves capable of bringing down a 500 kg (1,100 lb) moose. Digestion only takes a few hours, thus wolves can feed several times in one day, making quick use of large quantities of meat.

Although wolves primarily feed on medium to large sized ungulates, they are not fussy eaters. Smaller sized animals that may supplement the diet of wolves include marmots, hares, badgers, foxes, cats, weasels, ground squirrels, mice, hamsters, voles and other rodents, as well as insectivores. They frequently eat waterfowl and their eggs. When such foods are insufficient, they prey on lizards, snakes, frogs, rarely toads and large insects as available. In times of scarcity, wolves readily eat carrion, visiting cattle burial grounds and slaughter houses. Cannibalism is not uncommon in wolves: during harsh winters, packs often attack weak or injured wolves, and may eat the bodies of dead pack members. Wolf packs in Astrakhan hunt Caspian seals on the Caspian Sea coastline and some wolf packs in Alaska and Western Canada have been observed to feed on salmon. Wolves in northern Minnesota have also been observed hunting northern pike in freshwater streams. Humans are rarely, but occasionally, preyed upon. Other primates occasionally taken by wolves include grey langurs in Nepal and hamadryas baboons in Saudi Arabia.

In Eurasia, many gray wolf populations are forced to subsist largely on livestock and garbage in areas with dense human activity, though wild ungulates such as moose, red deer, roe deer and wild boar are still the most important food sources in Russia and the more mountainous regions of Eastern Europe. Other prey species include reindeer, argali, mouflon, wisent, saiga, ibex, chamois, wild goats, fallow deer and musk deer. The prey animals of North American wolves have largely continued to occupy suitable habitats with low human density, and cases of wolves subsisting largely on garbage or livestock are exceptional. Animals preferred as prey by North American wolves include moose, elk, white-tailed deer, mule deer, bighorn sheep, Dall's sheep, American bison, muskox and caribou.

Wolves supplement their diet with fruit and vegetable matter. They willingly eat the berries of mountain ash, lily of the valley, bilberries, blueberries and cowberry. Other fruits include nightshade, apples and pears. They readily visit melon fields during the summer months. A well-fed wolf stores fat under the skin, around the heart, intestines, kidneys, and bone marrow, particularly during the autumn and winter.

Behavior

See also: Dog behavior

Social behavior

Italian wolf pack

The gray wolf is a social animal, whose basic social unit consists of a mated pair, accompanied by the pair's adult offspring. The average pack consists of a family of five to 11 animals (one to two adults, three to six juveniles and one to three yearlings), or sometimes two or three such families, with exceptionally large packs consisting of up to 42 wolves being known. In ideal conditions, the mated pair produces pups every year, with such offspring typically staying in the pack for 10–54 months before dispersing. Triggers for dispersal include the onset of sexual maturity and competition within the pack for food. The distance travelled by dispersing wolves varies widely; some stay in the vicinity of the parental group, while other individuals may travel great distances of 206 km (128 mi), 390 km (240 mi), and 670 km (420 mi) from their natal packs. A new pack is usually founded by an unrelated dispersing male and female, travelling together in search of an area devoid of other hostile packs. Wolf packs rarely adopt other wolves into their fold, and typically kill them. In the rare cases where other wolves are adopted, the adoptee is almost invariably an immature animal (one to three years of age) unlikely to compete for breeding rights with the mated pair. In some cases, a lone wolf is adopted into a pack to replace a deceased breeder. During times of ungulate abundance (migration, calving etc.), different wolf packs may temporarily join forces. Studies of wolves' cortisol levels show that they rise significantly when a pack member dies, indicating the presence of stress.

Wolves are highly territorial animals, and generally establish territories far larger than they require to survive in order to assure a steady supply of prey. Territory size depends largely on the amount of prey available and the age of the pack's pups, tending to increase in size in areas with low prey populations or when the pups reach the age of six months, thus having the same nutritional needs as adults. Wolf packs travel constantly in search of prey, covering roughly 9% of their territory per day (average 25 km/d (16 mi/d)). The core of their territory is on average 35 km² (14 sq mi), in which they spend 50% of their time. Prey density tends to be much higher in the territory's surrounding areas, though wolves tend to avoid hunting in the fringes of their range unless desperate, because of the possibility of fatal encounters with neighboring packs. The smallest territory on record was held by a pack of six wolves in northeastern Minnesota, which occupied an estimated 33 km² (13 sq mi), while the largest was held by an Alaskan pack of ten wolves encompassing a 6,272 km² (2,422 sq mi) area. Wolf packs are typically settled, and usually only leave their accustomed ranges during severe food shortages.

Wolves defend their territories from other packs through a combination of scent marking, direct attacks and howling (see Communication). Scent marking is used for territorial advertisement, and involves urination, defecation and ground scratching. Scent marks are generally left every 240 m (260 yd) throughout the territory on regular travelways and junctions. Such markers can last for two to three weeks, and are typically placed near rocks, boulders, trees, or the skeletons of large animals. Territorial fights are among the principal causes of wolf mortality, with one study concluding that 14–65% of wolf deaths in Minnesota and the Denali National Park and Preserve were due to predation by other wolves.

Reproduction

See also: Canine reproduction

Gray wolves mating

The gray wolf is generally monogamous, with mated pairs usually remaining together for life. Upon the death of one mated wolf, pairs are quickly reestablished. Since males often predominate in any given wolf population, unpaired females are a rarity. If a dispersing male gray wolf is unable to establish a territory or find a mate, he mates with the daughters of already established breeding pairs from other packs. Such gray wolves are termed "Casanova wolves" and, unlike males from established packs, they do not form pair bonds with the females they mate with. Some gray wolf packs may have multiple breeding females this way, as is the case in Yellowstone National Park. Gray wolves also practice alloparental care, in which a wolf pair may adopt the pup or pups of another. This might take place if the original parents die or are for some reason separated from them. In addition to heterosexual behavior, homosexual behavior has been observed in gray wolves. Male gray wolves often mount each other when the highest ranking female in the pack comes into heat.

Illustrated growth stages of the northwestern wolf: newborn, three weeks old, two months old, and a one-year-old adult wolf

The age of first breeding in gray wolves depends largely on environmental factors: when food is plentiful, or when wolf populations are heavily managed, wolves can rear pups at younger ages in order to better exploit abundant resources. This is further demonstrated by the fact that captive wolves have been known to breed as soon as they reach nine to 10 months, while the youngest recorded breeding wolves in the wild were two years old. Females are capable of producing pups every year, with one litter annually being the average. Unlike the coyote, the gray wolf never reaches reproductive senescence. Estrus typically occurs in late winter, with older, multiparous females entering estrus two–three weeks earlier than younger females. During pregnancy, female wolves remain in a den located away from the peripheral zone of their territories, where violent encounters with other packs are more likely. Old females usually whelp in the den of their previous litter, while younger females typically den near their birthplace. The gestation period lasts 62–75 days, with pups usually being born in the summer period.

Wolves bear relatively large pups in small litters compared to other canid species. The average litter consists of five to six pups, with litter sizes tending to increase in areas where prey is abundant, though exceptionally large litters of 14–17 pups occur only 1% of the time. Pups are usually born in spring, coinciding with a corresponding increase in prey populations. Pups are born blind and deaf, and are covered in short soft grayish-brown fur. They weigh 300–500 g (11–18 oz) at birth, and begin to see after nine to 12 days. The milk canines erupt after one month. Pups first leave the den after three weeks. At 1.5 months of age, they are agile enough to flee from danger. Mother wolves do not leave the den for the first few weeks, relying on the fathers to provide food for them and their young. Pups begin to eat solid food at the age of three to four weeks. Pups have a fast growth rate during their first four months of life: during this period, a pup's weight can increase nearly 30 times. Wolf pups begin play-fighting at the age of three weeks, though unlike young coyotes and foxes, their bites are inhibited. Actual fights to establish hierarchy usually occur at five to eight weeks of age. This is in contrast to young coyotes and foxes, which may begin fighting even before the onset of play behavior. By autumn, the pups are mature enough to accompany adults on hunts for large prey.

Foraging

American bison standing its ground against wolves, thus increasing its chances of survival

Iberian wolf trotting in summer fur. They generally place their hind paws in the tracks made by the front paws.Mech 1981, p. 13

Although social animals, single wolves or mated pairs typically have higher success rates in hunting than do large packs, with single wolves having occasionally been observed to kill large prey such as moose, bison and muskoxen unaided. The gray wolf's sense of smell is relatively weakly developed when compared to that of some hunting dog breeds, being able to detect carrion upwind no farther than 2–3 kilometres (1.2–1.9 mi). Because of this, it rarely manages to capture hidden hares or birds, though it can easily follow fresh tracks. Its auditory perception is acute enough to be able to hear up to a frequency of 26 kHz, which is sufficient to register the fall of leaves in the autumn period. A gray wolf hunt can be divided into five stages:

• Locating prey: The wolves travel in search of prey through their power of scent, chance encounter, and tracking. Wolves typically locate their prey by scent, though they must usually be directly downwind of it. When a breeze carrying the prey's scent is located, the wolves stand alert, and point their eyes, ears and nose towards their target. In open areas, wolves may precede the hunt with group ceremonies involving standing nose-to-nose and wagging their tails. Once concluded, the wolves head towards their prey.
• The stalk: The wolves attempt to conceal themselves as they approach. As the gap between the wolves and their prey closes, the wolves quicken their pace, wag their tails, and peer intently, getting as close to their quarry as possible without making it flee.
• The encounter: Once the prey detects the wolves, it can either approach the wolves, stand its ground, or flee. Large prey, such as moose, elk, and muskoxen, usually stand their ground. Should this occur, the wolves hold back, as they require the stimulus of a running animal to proceed with an attack. If the targeted animal stands its ground, the wolves either ignore it, or try to intimidate it into running.
• The rush: If the prey attempts to flee, the wolves immediately pursue it. This is the most critical stage of the hunt, as wolves may never catch up with prey running at top speed. If their prey is travelling in a group, the wolves either attempt to break up the herd, or isolate one or two animals from it.
• The chase: A continuation of the rush, the wolves attempt to catch up with their prey and kill it. When chasing small prey, wolves attempt to catch up with their prey as soon as possible, while with larger animals, the chase is prolonged, in order to wear the selected prey out. Wolves usually give up chases after 1–2 km (0.62–1.3 mi), though one wolf was recorded to chase a deer for 21 km (13 mi). Both Russian and North American wolves have been observed to drive prey onto crusted ice, precipices, ravines, slopes and steep banks to slow them down.

Killing a moose in typical fashion: biting the hindquarters

The actual killing method varies according to prey species. With large prey, mature wolves usually avoid attacking frontally, instead focusing on the rear and sides of the animal. Large prey, such as moose, is killed by biting large chunks of flesh from the soft perineum area, causing massive blood loss. Such bites can cause wounds 10–15 cm (3.9–5.9 in) in length, with three such bites to the perineum usually being sufficient to bring down a large deer in optimum health. With medium-sized prey such as roe deer or sheep, wolves kill by biting the throat, severing nerve tracks and the carotid artery, thus causing the animal to die within a few seconds to a minute. With small, mouse-like prey, wolves leap in a high arc and immobilize it with their forepaws. When prey is vulnerable and abundant, wolves may occasionally surplus kill. Such instances are common in domestic animals, but rare in the wild. In the wild, surplus killing primarily occurs during late winter or spring, when snow is unusually deep (thus impeding the movements of prey) or during the denning period, when wolves require a ready supply of meat when denbound. Medium-sized prey are especially vulnerable to surplus killing, as the swift throat-biting method by which they are killed allows wolves to quickly kill one animal and move on to another.

Two gray wolves eating a white-tailed deer

Once prey is brought down, wolves begin to feed excitedly, ripping and tugging at the carcass in all directions, and bolting down large chunks of it. The breeding pair typically monopolizes food in order to continue producing pups. When food is scarce, this is done at the expense of other family members, especially non-pups. The breeding pair typically eats first, though as it is they who usually work the hardest in killing prey, they may rest after a long hunt and allow the rest of the family to eat unmolested. Once the breeding pair has finished eating, the rest of the family tears off pieces of the carcass and transport them to secluded areas where they can eat in peace. Wolves typically commence feeding by consuming the larger internal organs of their prey, such as the heart, liver, lungs and stomach lining. The kidneys and spleen are eaten once they are exposed, followed by the muscles. A single wolf can eat 15–19% of its body weight in a single feeding.

Communication

See also: Dog communication

Visual

The gray wolf's expressive behavior is more complex than that of the coyote and golden jackal, as necessitated by its group living and hunting habits. While less gregarious canids generally possess simple repertoires of visual signals, wolves have more varied signals that subtly inter grade in intensity. When neutral, the legs are not stiffened, the tail hangs down loosely, the face is smooth, the lips untensed, and the ears point in no particular direction. Postural communication in wolves consists of a variety of facial expressions, tail positions and piloerection. Aggressive, or self-assertive wolves are characterized by their slow and deliberate movements, high body posture and raised hackles, while submissive ones carry their bodies low, sleeken their fur and lower their ears and tail. When a breeding male encounters a subordinate family member, it may stare at it, standing erect and still with the tail horizontal to its spine. Two forms of submissive behavior are recognized: passive and active. Passive submission usually occurs as a reaction to the approach of a dominant animal, and consists of the submissive wolf lying partly on its back and allowing the dominant wolf to sniff its anogenital area. Active submission occurs often as a form of greeting, and involves the submissive wolf approaching another in a low posture, and licking the other wolf's face. When wolves are together, they commonly indulge in behaviors such as nose pushing, jaw wrestling, cheek rubbing and facial licking. The mouthing of each other's muzzles is a friendly gesture, while clamping on the muzzle with bared teeth is a dominance display.

Similar to humans, gray wolves have facial color patterns in which the gaze direction can be easily identified, although this is often not the case in other canid species. In 2014, a study compared the facial color pattern across 25 canid species. The results suggested that the facial color pattern of canid species is related to their gaze communication, and that especially gray wolves use the gaze signal in conspecific communication.

Facial expressions (Konrad Lorenz, 1952). Bottom to top: increasing fear (ears back); left to right: increasing aggression (snarl); top right: maximum of both.

Expressive characteristics of visual features
used during social interactions in wolves

Feature	Aggressive	Fearful
Eyes	Direct stare Open wide	Looking away Closed to slits
Ears	Erect and forward	Flattened and turned down to side
Lips	Horizontal contraction ("agonistic pucker")	Horizontal retraction ("submissive grin")
Mouth	Opened	Closed
Teeth	Canines bared	Canines covered
Tongue	Retracted	Extended ("lick intention")
Nose	Shortened (skin folded)	Lengthened (skin smoothed)
Forehead	Contracted (bulging over eyes)	Stretched (smoothed)
Head	Held high	Lowered
Neck	Arched	Extended
Hair	Erect (bristled)	Sleeked
Body	Erect, tall	Crouched, low
Tail	Held high Quivering	Tucked under body Wagging

Auditory

Gray wolf howling

Gray wolves howl to assemble the pack (usually before and after hunts), to pass on an alarm (particularly at a den site), to locate each other during a storm or unfamiliar territory and to communicate across great distances. Wolf howls can under certain conditions be heard over areas of up to 130 km² (50 sq mi). Wolf howls are generally indistinguishable from those of large dogs. Male wolves give voice through an octave, passing to a deep bass with a stress on "O", while females produce a modulated nasal baritone with stress on "U". Pups almost never howl, while yearling wolves produce howls ending in a series of dog-like yelps. Howling consists of a fundamental frequency that may lie between 150 and 780 Hz, and consists of up to 12 harmonically related overtones. The pitch usually remains constant or varies smoothly, and may change direction as many as four or five times. Howls used for calling pack mates to a kill are long, smooth sounds similar to the beginning of the cry of a great horned owl. When pursuing prey, they emit a higher pitched howl, vibrating on two notes. When closing in on their prey, they emit a combination of a short bark and a howl. When howling together, wolves harmonize rather than chorus on the same note, thus creating the illusion of there being more wolves than there actually are. Lone wolves typically avoid howling in areas where other packs are present. Wolves from different geographic locations may howl in different fashions: the howls of European wolves are much more protracted and melodious than those of North American wolves, whose howls are louder and have a stronger emphasis on the first syllable. The two are however mutually intelligible, as North American wolves have been recorded to respond to European-style howls made by biologists.

Other vocalisations of wolves are usually divided into three categories: growls, barks and whines. Barking has a fundamental frequency between 320–904 Hz, and is usually emitted by startled wolves. Wolves do not bark as loudly or continuously as dogs do, but bark a few times and retreat from perceived danger. Growling has a fundamental frequency of 380–450 Hz, and is usually emitted during food challenges. Pups commonly growl when playing. One variation of the howl is accompanied by a high pitched whine, which precedes a lunging attack. Whining is associated with situations of anxiety, curiosity, inquiry and intimacy such as greeting, feeding pups and playing.

Olfactory

Gray wolf marking its territory with urine

Olfaction is probably the wolf's most acute sense, and plays a fundamental role in communication. The wolf has a large number of apocrine sweat glands on the face, lips, back, and between the toes. The odor produced by these glands varies according to the individual wolf's microflora and diet, giving each a distinct "odor fingerprint". A combination of apocrine and eccrine sweat glands on the feet allows the wolf to deposit its scent whilst scratching the ground, which usually occurs after urine marking and defecation during the breeding season. The follicles present on the guard hairs from the wolf's back have clusters of apocrine and sebaceous glands at their bases. As the skin on the back is usually folded, this provides a microclimate for bacterial propagation around the glands. During piloerection, the guard hairs on the back are raised and the skin folds spread, thus releasing scent.

The precaudal scent glands may play a role in expressing aggression, as combative wolves raise the base of their tails whilst drooping the tip, thus positioning the scent glands at the highest point. The wolf possesses a pair of anal sacs beneath the rectum, which contain both apocrine and sebaceous glands. The components of anal sac secretions vary according to season and gender, thus indicating that the secretions provide information related to gender and reproductive state. The secretions of the preputial glands may advertise hormonal condition or social position, as dominant wolves have been observed to stand over subordinates, apparently presenting the genital area for investigation, which may include genital licking.

During the breeding season, female wolves secrete substances from the vagina, which communicate the females' reproductive state, and can be detected by males from long distances. Urine marking is the best-studied means of olfactory communication in wolves. Its exact function is debated, though most researchers agree that its primary purpose is to establish boundaries. Wolves urine mark more frequently and vigorously in unfamiliar areas, or areas of intrusion, where the scent of other wolves or canids is present. So-called raised leg urination (RLU) is more common in male wolves than in females, and may serve the purpose of maximizing the possibility of detection by conspecifics, as well as reflect the height of the marking wolf. Only dominant wolves typically use RLU, with subordinate males continuing to use the juvenile standing posture throughout adulthood. RLU is considered to be one of the most important forms of scent communication in the wolf, making up 60–80% of all scent marks observed.

Cooperation

In 1994 near Eilat in southern Israel, researchers discovered the tracks of three gray wolves and one striped hyena which indicated that they were moving across the landscape together. In 1998 near the same location, three researchers sighted a pack consisting of 4 adult and 3 sub-adult gray wolves and one striped hyaena. The hyaena was moving in the middle of the pack and not following behind it. It is proposed that the hyaena could benefit from the wolves’ superior ability to hunt large, agile prey. The wolves could benefit from the hyaena's superior sense of smell, to locate and dig out tortoises, to crack open large bones, and to tear open discarded food containers such as tin cans.

Competition

Gray wolves attacking a mother grizzly bear with cubs

Gray wolves confronting coyotes over a pronghorn carcass (1919), Louis Agassiz Fuertes

Gray wolves typically dominate other canid species in areas where they both occur. In North America, incidents of gray wolves killing coyotes are common, particularly in winter, when coyotes feed on wolf kills. Wolves may attack coyote den sites, digging out and killing their pups, though rarely eating them. There are no records of coyotes killing wolves, though coyotes may chase wolves if they outnumber them. Near-identical interactions have been observed in Eurasia between gray wolves and golden jackals, with the latter's numbers being comparatively small in areas with high wolf densities. Gray wolves are the most important predator of raccoon dogs, killing large numbers of them in the spring and summer periods. Wolves also kill red, Arctic and corsac foxes, usually in disputes over carcasses, sometimes eating them. In Asia, they may compete with dholes, though there is at least one record of a lone wolf associating with a pair of dholes in Debrigarh Wildlife Sanctuary.

Brown bears typically dominate wolf packs in disputes over carcasses, while wolf packs mostly prevail against bears when defending their den sites. Both species kill each other's young. Wolves eat the brown bears they kill, while brown bears seem to only eat young wolves. Wolf interactions with American black bears are much rarer than with brown bears, because of differences in habitat preferences. The majority of American black bear encounters with wolves occur in the species' northern range, with no interactions being recorded in Mexico. Wolves have been recorded on numerous occasions to actively seek out American black bears in their dens and kill them without eating them. Unlike brown bears, American black bears frequently lose against wolves in disputes over kills. While encounters with brown and American black bears appear to be common, polar bears are rarely encountered by wolves, though there are two records of wolf packs killing polar bear cubs. Wolves also kill the cubs of Asian black bears.

Wolves may encounter striped hyenas in Israel, Central Asia and India, usually in disputes over carcasses. Striped hyenas feed extensively on wolf-killed carcasses in areas where the two species interact. One-on-one, hyenas dominate wolves, and may prey on them, but wolf packs can drive off single or outnumbered hyenas. However, there was a case of a female striped hyena dominating 12 Arabian wolves.

Large wolf populations limit the numbers of small to medium-sized felines. Wolves encounter cougars along portions of the Rocky Mountains and adjacent mountain ranges. Wolves and cougars typically avoid encountering each other by hunting on different elevations. In winter, however, when snow accumulation forces their prey into valleys, interactions between the two species become more likely. Wolves in packs usually dominate cougars and can steal their kills. They have been reported killing mothers and their kittens. Wolves hunt steppe cats, and may scavenge from snow leopard kills. Wolves may also reduce Eurasian lynx populations. Wolves may kill lynxes by running them down, or killing them before they can escape into the trees. Similar reports of encounters between wolves and bobcats have been documented.

Leftovers of wolf kills are sometimes scavenged by wolverines. Wolverines usually wait until the wolves are done feeding, but have been known to drive away wolves from their kills. However, there have been confirmed reports of wolf packs killing wolverines.

Other than humans, tigers appear to be the only serious predators of wolves. Wolf and tiger interactions are well documented in Sikhote-Alin, where tigers depress wolf numbers, either to the point of localized extinction or to such low numbers as to make them a functionally insignificant component of the ecosystem. Wolves appear capable of escaping competitive exclusion from tigers only when human persecution decreases tiger numbers. Proven cases of tigers killing wolves are rare and attacks appear to be competitive rather than predatory in nature, with at least four proven records of tigers killing wolves without consuming them.

Diseases and parasites

Viral and bacterial infections

Footage of a gray wolf taken from Abruzzo Natural Park showing advanced signs of canine distemper

Viral diseases carried by wolves include rabies, canine distemper, canine parvovirus, infectious canine hepatitis, papillomatosis, canine coronavirus, and foot and mouth disease. Wolves are a major host for rabies in Russia, Iran, Afghanistan, Iraq and India. In wolves, the incubation period is eight to 21 days, and results in the host becoming agitated, deserting its pack, and travelling up to 80 kilometres (50 mi) a day, thus increasing the risk of infecting other wolves. Infected wolves do not show any fear of humans, with most documented wolf attacks on people being attributed to rabid animals. Although canine distemper is lethal in dogs, it has not been recorded to kill wolves, except in Canada and Alaska. The canine parvovirus, which causes death by dehydration, electrolyte imbalance, and endotoxic shock or sepsis, is largely survivable in wolves, but can be lethal to pups. Wolves may catch infectious canine hepatitis from dogs, though there are no records of wolves dying from it. Papillomatosis has been recorded only once in wolves, and likely does not cause serious illness or death, though it may alter feeding behaviors. The canine coronavirus has been recorded in Alaskan wolves, with infections being most prevalent in winter months.

Bacterial diseases carried by wolves include brucellosis, lyme disease, leptospirosis, tularemia, bovine tuberculosis, listeriosis and anthrax. Wolves can catch Brucella suis from wild and domestic reindeer. While adult wolves tend not to show any clinical signs, it can severely weaken the pups of infected females. Although lyme disease can debilitate individual wolves, it does not appear to have any significant effect on wolf populations. Leptospirosis can be contracted through contact with infected prey or urine, and can cause fever, anorexia, vomiting, anemia, hematuria, icterus, and death. Wolves living near farms are more vulnerable to the disease than those living in the wilderness, probably because of prolonged contact with infected domestic animal waste. Wolves may catch tularemia from lagomorph prey, though its effect on wolves is unknown. Although bovine tuberculosis is not considered a major threat to wolves, it has been recorded to have once killed two wolf pups in Canada.

Parasitic infections

Wolves carry ectoparasites and endoparasites, with wolves in the former Soviet Union having been recorded to carry at least 50 species. Most of these parasites infect wolves without adverse effects, though the effects may become more serious in sick or malnourished specimens. Parasitic infection in wolves is of particular concern to people, as wolves can spread them to dogs, which in turn can carry the parasites to humans. In areas where wolves inhabit pastoral areas, the parasites can be spread to livestock.

Wolf with sarcoptic mange

Wolves are often infested with a variety of arthropod exoparasites, including fleas, ticks, lice, and mites. The most harmful to wolves, particularly pups, is the mange mite (Sarcoptes scabiei), though they rarely develop full-blown mange, unlike foxes. Lice, such as Trichodectes canis, may cause sickness in wolves, but rarely death. Ticks of the genus Ixodes can infect wolves with Lyme disease and Rocky Mountain spotted fever. The tick Dermacentor pictus also infests wolves. Other ectoparasites include chewing lice, sucking lice and the fleas Pulex irritans and Ctenocephalides canis.

Endoparasites known to infect wolves include protozoans and helminths (flukes, tapeworms, roundworms and thorny-headed worms). Of 30,000 protozoan species, only a few have been recorded to infect wolves: Isospora, Toxoplasma, Sarcocystis, Babesia, and Giardia. Wolves may carry Neospora caninum, which is of particular concern to farmers, as the disease can be spread to livestock, with infected animals being three to 13 times more likely to miscarry than those not infected. Among flukes, the most common in North American wolves is Alaria, which infects small rodents and amphibians that are eaten by wolves. Upon reaching maturity, Alaria migrates to the wolf's intestine, but harms it little. Metorchis conjunctus, which enters wolves through eating fish, infects the wolf's liver or gall bladder, causing liver disease, inflammation of the pancreas, and emaciation. Most other fluke species reside in the wolf's intestine, though Paragonimus westermani lives in the lungs. Tapeworms are commonly found in wolves, as their primary hosts are ungulates, small mammals, and fish, which wolves feed upon. Tapeworms generally cause little harm in wolves, though this depends on the number and size of the parasites, and the sensitivity of the host. Symptoms often include constipation, toxic and allergic reactions, irritation of the intestinal mucosa, and malnutrition. Infections by the tapeworm Echinococcus granulosus in ungulate populations tend to increase in areas with high wolf densities, as wolves can shed Echinoccocus eggs in their feces onto grazing areas. Wolves can carry over 30 roundworm species, though most roundworm infections appear benign, depending on the number of worms and the age of the host. Ancylostoma caninum attaches itself on the intestinal wall to feed on the host's blood, and can cause hyperchromic anemia, emaciation, diarrhea, and possibly death. Toxocara canis, a hookworm known to infect wolf pups in utero, can cause intestinal irritation, bloating, vomiting, and diarrhea. Wolves may catch Dioctophyma renale from minks, which infects the kidneys, and can grow to lengths of 100 cm. D. renale causes the complete destruction of the kidney's functional tissue, and can be fatal if both kidneys are infected. Wolves can tolerate low levels of Dirofilaria immitis for many years without showing any ill effects, though high levels can kill wolves through cardiac enlargement and congestive hepatopathy. Wolves probably become infected with Trichinella spiralis by eating infected ungulates. Although T. spiralis is not known to produce clinical signs in wolves, it can cause emaciation, salivation, and crippling muscle pains in dogs. Thorny-headed worms rarely infect wolves, though three species have been identified in Russian wolves: Nicolla skrjabini, Macrocantorhynchus catulinus, and Moniliformis moniliformis.

Conservation

The species is included in CITES Appendix II, except populations from Bhutan, India, Nepal and Pakistan, which are listed on Appendix I. The species is strictly protected under the 1979 Berne Convention on the Conservation of European Wildlife and Natural Habitats (Appendix II) and the 1992 European Union Council Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild Fauna and Flora (Annex II and IV), and there is extensive legal protection in many European countries; however, there are national exceptions, and enforcement is variable and often non-existent. The Grey Wolf occurs in many protected areas across its range, and breeds well in captivity and is common in many zoological gardens. The gray wolf received Endangered Species Act (ESA) protection in Minnesota, Wisconsin, and Michigan in 1974, and was reclassified from endangered to threatened in 2003. Reintroduced Mexican wolves in Arizona and New Mexico are protected under the ESA and, as of late 2002, number 28 individuals in eight packs.

Relationships with humans

Human presence appears to stress wolves, as seen by increased cortisol levels in instances such as snowmobiling near their territory.

In culture

In personal names

Old English literature contains several instances of Anglo-Saxon kings and warriors taking on wulf as a prefix or suffix in their names. Examples include Wulfhere, Cynewulf, Ceonwulf, Wulfheard, Earnwulf, Wulfmǣr, Wulfstān and Æthelwulf. Wolf-related names were also common among pre-Christian Germanic warriors: Wolfhroc (Wolf-Frock), Wolfhetan (Wolf Hide), Isangrim (Grey Mask), Scrutolf (Garb Wolf), Wolfgang (Wolf Gait) and Wolfdregil (Wolf Runner).

In folklore, religion and mythology

Main article: Wolves in folklore, religion and mythology

Capitoline Wolf, sculpture of the mythical she-wolf feeding the twins Romulus and Remus, from the legend of the founding of Rome, Italy.

The wolf is a common motif in the foundational mythologies and cosmologies of peoples throughout Eurasia and North America (corresponding to the historical extent of the habitat of the gray wolf). The obvious attribute of the wolf is its nature of a predator, and correspondingly it is strongly associated with danger and destruction, making it the symbol of the warrior on one hand, and that of the devil on the other. The modern trope of the Big Bad Wolf is a development of this. The wolf holds great importance in the cultures and religions of the nomadic peoples, both of the Eurasian steppe and of the North American Great Plains. In many cultures, the identification of the warrior with the wolf (totemism) gave rise to the notion of lycanthropy, the mythical or ritual identification of man and wolf.

In fable and literature

Little Red Riding Hood (1883), Gustave Doré

Aesop featured wolves in several of his fables, playing on the concerns of Ancient Greece's settled, sheep-herding world. His most famous is the fable of "The Boy Who Cried Wolf", which is directed at those who knowingly raise false alarms, and from which the idiomatic phrase "to cry wolf" is derived. Some of his other fables concentrate on maintaining the trust between shepherds and guard dogs in their vigilance against wolves, as well as anxieties over the close relationship between wolves and dogs. Although Aesop used wolves to warn, criticize and moralize about human behavior, his portrayals added to the wolf's image as a deceitful and dangerous animal. Isengrim the wolf, a character first appearing in the 12th-century Latin poem Ysengrimus, is a major character in the Reynard Cycle, where he stands for the low nobility, whilst his adversary, Reynard the fox, represents the peasant hero. Although portrayed as loyal, honest and moral, Isengrim is forever the victim of Reynard's wit and cruelty, often dying at the end of each story.

The tale of Little Red Riding Hood, first written in 1697 by Charles Perrault, is largely considered to have had more influence than any other source of literature in forging the wolf's negative reputation in the western world. The wolf in this story is portrayed as a potential rapist, capable of imitating human speech. The hunting of wolves, and their attacks on humans and livestock feature prominently in Russian literature, and are included in the works of Tolstoy, Chekhov, Nekrasov, Bunin, Sabaneyev, and others. Tolstoy's War and Peace and Chekhov's Peasants both feature scenes in which wolves are hunted with hounds and borzois. Farley Mowat's largely fictional 1963 memoir Never Cry Wolf was the first positive portrayal of wolves in popular literature, and is largely considered to be the most popular book on wolves, having been adapted into a Hollywood film and taught in several schools decades after its publication. Although credited with having changed popular perceptions on wolves by portraying them as loving, cooperative and noble, it has been criticized for its idealization of wolves and its factual inaccuracies.

In heraldry and symbolism

Main article: Wolves in heraldry

Coat of arms of the Elvange family, featuring a wolf charge rampant

The wolf is a frequent charge in English armory. It is illustrated as a supporter on the shields of Lord Welby, Rendel, and Viscount Wolseley, and can be found on the coat of arms of Lovett and the vast majority of the Wilsons and Lows. The demi-wolf is a common crest, appearing in the arms and crests of members of many families, including that of the Wolfes, whose crest depicts a demi-wolf holding a crown in its paws, in reference to the assistance the family gave to Charles II during the battle of Worcester. Wolf heads are common in Scottish heraldry, particularly in the coats of Clan Robertson and Skene. The wolf is the most common animal in Spanish heraldry, and is often depicted as carrying a lamb in its mouth, or across its back. The wolf is featured on the flags of the Confederated Tribes of the Colville Reservation, the Oneida Nation of Wisconsin and the Pawnee. In modern times, the wolf is widely used as an emblem for military and paramilitary groups. It is the unofficial symbol of the spetsnaz, and serves as the logo of the Turkish Grey Wolves. During the Yugoslav Wars, several Serb paramilitary units adopted the wolf as their symbol, including the White Wolves and the Wolves of Vučjak.

Conflicts

Waiting for a Chinook (c. 1900), Charles Marion Russell

Wolf predation on livestock

Livestock depredation has been one of the primary reasons for hunting wolves, and can pose a severe problem for wolf conservation: as well as causing economic losses, the threat of wolf predation causes great stress on livestock producers, and no foolproof solution of preventing such attacks short of exterminating wolves has been found. Some nations help offset economic losses to wolves through compensation programmes or state insurance. Domesticated animals are easy prey for wolves, as they have evolved under constant human protection, and are thus unable to defend themselves very well. Wolves typically resort to attacking livestock when wild prey is depleted: in Eurasia, a large part of the diet of some wolf populations consists of livestock, while such incidents are rare in North America, where healthy populations of wild prey have been largely restored. The majority of losses occur during the summer grazing period, with untended livestock in remote pastures being the most vulnerable to wolf predation. The most frequently targeted livestock species are sheep (Europe), domestic reindeer (northern Scandinavia), goats (India), horses (Mongolia), cattle and turkeys (North America). The number of animals killed in single attacks varies according to species: most attacks on cattle and horses result in one death, while turkeys, sheep and domestic reindeer may be killed in surplus. Wolves mainly attack livestock when the animals are grazing, though they occasionally break into fenced enclosures. In some cases, wolves do not need to physically attack livestock to negatively affect it: the stress livestock experiences in being vigilant for wolves may result in miscarriages, weight loss and a decrease in meat quality.

Conflicts with dogs

Being the most abundant carnivores, free-ranging dogs have the greatest potential to compete with wolves. A review of the studies in the competitive effects of dogs on sympatric carnivores did not mention any research on competition between dogs and wolves. Competition would favor the wolf, which is known to kill dogs, however wolves tend to live in pairs or in small packs in areas where they are highly persecuted, giving them a disadvantage facing large groups of dogs.

Wolves kill dogs on occasion, with some wolf populations relying on dogs as an important food source. In Croatia, wolves kill more dogs than sheep, and wolves in Russia appear to limit stray dog populations. Wolves may display unusually bold behavior when attacking dogs accompanied by people, sometimes ignoring nearby humans. Wolf attacks on dogs may occur both in house yards and in forests. Wolf attacks on hunting dogs are considered a major problem in Scandinavia and Wisconsin. The most frequently killed hunting breeds in Scandinavia are harriers, with older animals being most at risk, likely because they are less timid than younger animals, and react to the presence of wolves differently. Large hunting dogs such as Swedish elkhounds are more likely to survive wolf attacks because of their better ability to defend themselves.

Although the numbers of dogs killed each year are relatively low, it induces a fear of wolves entering villages and farmyards to take dogs. In many cultures, there are strong social and emotional bonds between humans and their dogs that can be seen as family members or working team members. The loss of a dog can lead to strong emotional responses with demands for more liberal wolf hunting regulations.

Dogs that are employed to guard sheep help to mitigate human–wolf conflicts, and are often proposed as one of the non-lethal tools in the conservation of wolves. Shepherd dogs are not particularly aggressive, but they can disrupt potential wolf predation by displaying what is to the wolf ambiguous behaviors, such as barking, social greeting, invitation to play or aggression. The historical use of shepherd dogs across Eurasia has been effective against wolf predation, especially when confining sheep in the presence of several livestock guardian dogs. However, shepherd dogs are sometimes killed by wolves.

Wolf predation on humans

Main articles: Wolf attacks on humans and List of wolf attacks

Small farmers surprised by a wolf (1833) by François Grenier de Saint-Martin

The fear of wolves has been pervasive in many societies, though humans are not part of the wolf's natural prey. How wolves react to humans depends largely on their prior experience with people: wolves lacking any negative experience of humans, or which are food-conditioned, may show little fear of people. Although wolves may react aggressively under provocation, such attacks are mostly limited to quick bites on extremities, and the attacks are not pressed. Predatory attacks (attacks by wolves treating humans as food) may be preceded by a long period of habituation, in which wolves gradually lose their fear of humans. The victims are repeatedly bitten on the head and face, and are then dragged off and consumed, unless the wolves are driven off. Such attacks typically occur only locally, and do not stop until the wolves involved are eliminated. Predatory attacks can occur at any time of the year, with a peak in the June–August period, when the chances of people entering forested areas (for livestock grazing or berry and mushroom picking) increase, though cases of non-rabid wolf attacks in winter have been recorded in Belarus, Kirov and Irkutsk oblasts, Karelia and Ukraine. Also, wolves with pups experience greater food stresses during this period.

The majority of victims of predatory wolf attacks are children under the age of 18 and, in the rare cases where adults are killed, the victims are almost always women. Cases of rabid wolves are low when compared to other species, as wolves do not serve as primary reservoirs of the disease, but can be infected by animals such as dogs, jackals and foxes. Incidents of rabies in wolves are very rare in North America, though numerous in the eastern Mediterranean, Middle East and Central Asia. Wolves apparently develop the "furious" phase of rabies to a very high degree which, coupled with their size and strength, makes rabid wolves perhaps the most dangerous of rabid animals, with bites from rabid wolves being 15 times more dangerous than those of rabid dogs. Rabid wolves usually act alone, travelling large distances and often biting large numbers of people and domestic animals. Most rabid wolf attacks occur in the spring and autumn periods. Unlike with predatory attacks, the victims of rabid wolves are not eaten, and the attacks generally only occur on a single day. The victims are chosen at random, though the majority of cases involve adult men. During the 50 years to 2002, there were eight fatal attacks in Europe and Russia, and more than 200 in southern Asia.

Human predation on wolves

Main articles: Wolf hunting and Wolf hunting with dogs

Carcasses of hunted wolves in Russia

Theodore Roosevelt stated that wolves are difficult to hunt because of their elusiveness, sharp senses, high endurance, and ability to quickly incapacitate and kill hunting dogs. Historic methods include killing of spring-born litters in their dens, coursing with dogs (usually combinations of sighthounds, bloodhounds and fox terriers), poisoning with strychnine, and trapping. A popular method of wolf hunting in Russia involves trapping a pack within a small area by encircling it with fladry poles carrying a human scent. This method relies heavily on the wolf's fear of human scents, though it can lose its effectiveness when wolves become accustomed to the smell. Some hunters are able to lure wolves by imitating their calls. In Kazakhstan and Mongolia, wolves are traditionally hunted with eagles and falcons, though this practice is declining, as experienced falconers are becoming few in number. Shooting wolves from aircraft is highly effective, due to increased visibility and direct lines of fire, but is controversial. Several types of dog, including the Borzoi, Irish Wolfhound, and Kyrgyz Tajgan, have been specifically bred for wolf hunting.

See also: Human uses of hunted wolves

As pets and working animals

Main article: Wolves as pets and working animals

Wild wolves are sometimes kept as exotic pets and, in some rarer occasions, as working animals. Although closely related to domesticated dogs, wolves do not show the same tractability as dogs in living alongside humans, and generally, much more work is required in order to obtain the same amount of reliability. Wolves also need much more space than dogs, about 26–39 square kilometres (10–15 sq mi), so they can exercise.

Etymology

The English 'wolf' stems from the Old English wulf, which is itself thought to be derived from the Proto-Germanic *wulfaz. The Latin lupus is a Sabine loanword. Both derive from the Proto-Indo-European root *wlq^wos or *luk^wos.

See also

• Custer wolf

Bibliography

• Graves, Will (2007). Wolves in Russia: Anxiety throughout the ages. Detselig Enterprises. ISBN 978-1-55059-332-7. {{cite book}}: Invalid |ref=harv (help)
• Lopez, Barry H. (1978). Of Wolves and Men. J. M. Dent and Sons Limited. ISBN 978-0-7432-4936-2. {{cite book}}: Invalid |ref=harv (help)
• Marvin, Garry (2012). Wolf. Reaktion Books Ldt. ISBN 978-1-86189-879-1. {{cite book}}: Invalid |ref=harv (help)
• Mech, L. David (1981). The Wolf: The Ecology and Behaviour of an Endangered Species. University of Minnesota Press. ISBN 978-0-8166-1026-6. {{cite book}}: Invalid |ref=harv (help)
• Mech, L. David; Boitani, Luigi, eds. (2003). Wolves: Behaviour, Ecology and Conservation. University of Chicago Press. ISBN 978-0-226-51696-7. {{cite book}}: Invalid |ref=harv (help)
• Van Nuys, Frank (2015). Varmints and Victims: Predator Control in the American West. Lawrence, KS: University Press of Kansas.
• Walker, Brett L. (2005). The Lost Wolves Of Japan. University of Washington Press. ISBN 978-0-295-98492-6. {{cite book}}: Invalid |ref=harv (help)
• Young, Stanley P.; Goldman, Edward A. (1944). The Wolves of North America, Part I. New York, Dover Publications, Inc. {{cite book}}: Invalid |ref=harv (help)
• Zimen, Erik (1981). The Wolf: His Place in the Natural World. Souvenir Press. ISBN 978-0-285-62411-5. {{cite book}}: Invalid |ref=harv (help)

Further reading

• Apollonio, Marco; Mattioli, Luca (2006). Il Lupo in Provincia di Arezzo (in Italian). Editrice Le Balze. ISBN 978-88-7539-123-2.
• Bibikov, D. I. (1985). "Volk: Proiskhozhdenie, sistematika, morfologia, ekologia [The Wolf: History, Systematics, Morphology and Ecology]" (in Russian). Nauka, Moscow, USSR. ASIN B001A1TKK4. {{cite journal}}: Cite journal requires |journal= (help)
• Busch, Robert H. (2009). Wolf Almanac. The Lyons Press. ISBN 978-1-59921-069-8.
• Coleman, Jon T. (2006). Vicious: Wolves and Men in America. Yale University Press. ISBN 978-0-300-11972-5.
• Dutcher, Jim; Dutcher, Jamie (2003). Wolves at Our Door: The Extraordinary Story of the Couple Who Lived with Wolves. William Andrew. ISBN 978-0-7434-0049-7.
• Fischer, Hank (1995). Wolf Wars. Falcon. ISBN 978-1-56044-352-0.
• Fuller, Todd K. (2004). Wolves of the World. Voyageur Press. ISBN 978-0-89658-640-6.
• Grooms, Steve (1999). Return of the Wolf. Northword Press. ISBN 978-1-55971-717-5.
• Hampton, Bruce (1997). The Great American Wolf. Holt Paperbacks. ISBN 978-0-8050-5528-3.
• Harrington, Fred H.; Paquet, Paul C. (1982). Wolves of the world: perspectives of behavior, ecology, and conservation. Simon & Schuster. ISBN 978-0-8155-0905-9.
• McIntyre, Rick (1996). A Society of Wolves: National Parks and the Battle over the Wolf. Voyageur Press. ISBN 978-0-89658-325-2.
• McNamee, Thomas (1998). The Return of the Wolf to Yellowstone. Holt Paperbacks. ISBN 978-0-8050-5792-8.
• Mech, L. David (1966). Wolves of Isle Royale. U.S. Department of the Interior, Park Service.
• Mech, L. David (1993). The Way of the Wolf. Voyageur Press. ISBN 978-0-89658-179-1.
• Murie, Adolph (1944). Wolves of Mount McKinley. U.S. Department of the Interior, Park Service.
• Musiani, Marco; Boitani, Luigi; Paquet, Paul C. (2010). The World of Wolves: New Perspectives on Ecology, Behaviour, and Management. University of Calgary Press. ISBN 978-1-55238-269-1.
• Nie, Martin (2003). Beyond Wolves: The Politics of Wolf Recovery and Management. University of Minnesota Press. ISBN 978-0-300-11972-5.
• Peterson, Rolf Olin (1977). Wolf Ecology and Prey Relationships on Isle Royale. National Park Service Scientific Monograph Series.
• Weaver, John (1978). Wolves of Yellowstone. U.S. Department of the Interior, Park Service.

External links

• Dog (mammal) at the Encyclopædia Britannica
• Gray wolf (mammal) at the Encyclopædia Britannica
• Wolf (mammal) at the Encyclopædia Britannica
• California Wolf Center
• The International Wolf Center
• Staying Safe in Wolf Country, ADFG (January 2009)
• UK Wolf Conservation Trust
• Watch Death of a Legend and Cry of the Wild by Bill Mason