The grey wolf is the largest species of wild canid and was once the most widespread terrestrial mammal, ranging across North America from Mexico to the Arctic, as well as most of Eurasia - though their range is now greatly reduced. They are adaptable and intelligent predators capable of hunting a wide variety of prey, from rodents to large undulates. Most wolves live in 'packs' - family units which usually consist of 5 to 12 related individuals, and are lead by a dominant male and female.
Wolves can thrive in many different habitats, including forests, mountain ranges, plains, deserts, tundra and even the vast, snowy expanse of the Arctic. Though their range is not as expansive as it used to be, it still covers large areas of North America and Greenland, northern Scandinavia and almost the entirety of Asia, from northern Russia to India. They exist in smaller populations throughout western Europe.
Wolves have very complex social bonds and many methods of communication, which allows them to work together when hunting and raising young. Most wolves live in packs, ranging in size from only a few individuals to over 40, depending on the location and prey availability. The smallest packs consist of only a breeding pair and their offspring; larger packs can also include extended family, including aunts, uncles, siblings, and even adopted, unrelated individuals.
Most packs are lead by two dominant wolves that act as parents for the whole pack - they typically consist of a male and female breeding pair, and are often the biological parents of most, if not all, of the members of the pack. They are responsible for deciding where the dens are made, coordinating hunts and disciplining the other wolves in the pack, among other things. During times of hardship, the dominant pair is also the only pair allowed to breed and they will enforce this aggressively.
Wolves communicate with each other via a complex array of vocalisations - barks, whimpers and growls, for example - as well as through body language and scent. Probably the most well known lupine vocalisation is the howl, which is used for long-distance communication between pack mates. Defensive howls can be territorial, and rally the pack together to defend against intruders; social howls are used to locate other wolves, and also possibly just for fun. A bark is used to alert pack mates to an external threat, such as a large predator. Growls are typically used as a warning in wolf-to-wolf conflicts.
Wolves use scent to mark their territory, allowing communication between wolves of different packs without direct contact and confrontation. When two packs meet, they will almost always fight. However, a pack's reaction to a lone wolf varies depending on the leaders' temperaments - it's rare that a pack will kill a lone wolf unprovoked, and occasionally such wolves are even allowed to join the pack, though they are usually chased off.
Wolves show affection through social grooming, muzzle licking, cuddling and playful nipping. They are curious and playful animals, and may pester others to play through pawing and play bowing, in a similar way to domestic dogs.
Wolves have an acute sense of both smell and hearing, as well as keen eyesight. Wolves can hear sounds at a range of six to ten miles depending on the terrain, and can detect frequencies imperceptible to human ears. Each ear can turn individually, which means they can better hone in on a particular sound. Wolves also cock their heads at unfamiliar sounds for the same reason.
Wolves' sense of smell is roughly a hundred times better than a human's; they can likely smell prey from over a mile away, and identify individual wolves on scent alone. A wolf's sense of smell is vital to inter-pack communication, and also allows a wolf to gauge the state of its target prey, being able to tell whether a target is ill or dying based on the smell it leaves behind.
Their eyesight is mainly focused on picking up the slightest movements even at a distance, aiding them in locating prey. However, their vision is not designed to pick up details, so while a wolf can see movement at a very long distance, it may struggle to identify what is moving - their vision is similar to near-sightedness in humans. Wolves have exceptional night vision due to the high amount of rod cells in their eyes (which are good at detecting light, but not colour) and their larger pupils. Wolves, like dogs, can see the colours blue and yellow, but not red or green - similar to deuteranopia (red-green colour blindness) in humans.
Wolves are almost exclusively predatory, feeding on a wide variety of prey animals including rodents, deer, bison, game birds, domesticated livestock, reptiles, fish, and even other wolves. They also occasionally supplement their diet with plant matter, such as berries and the half-digested plant material in their preys' stomachs.
Lone wolves and couples can take down game up to the size of a small deer on their own, planning their attack carefully and ambushing their prey in a location that prevents it using its faster running speed to escape. When hunting in packs to take down larger prey, wolves will often trail their target herd for days, watching for weakness and waiting until their presence causes their desired prey to panic, then targeting any individual who falters or falls behind.
Wolves are too small to deal a single killing blow, so instead attack savagely, inflicting as many small wounds as possible then waiting for their prey to die of blood loss, muscle damage or shock; they often eat their prey while it is still alive. They hunt only for their own survival - hunting is a huge risk for a wolf to take, as their prey is often larger and stronger than any individual wolf, and a well-aimed kick from a large deer is enough to incapacitate or even kill a wolf outright.
Not all wolves that tag along for a hunt actively participate. Inexperienced pups will often watch from the sidelines, observing the others and learning from them.
There are many distinct subspecies of Canis lupus
, populating many different areas and adapted to survive in the particular habitat they call home; the size, appearance, diet and even behaviour varies greatly between different subspecies.
North American wolves typically have smaller ears and shorter muzzles than their Eurasian cousins, and are also more timid and fearful towards humans. Their coats are most commonly in tones of grey. Eurasian subspecies are more slender, with narrower heads and larger ears; their coats are coarser than those of American wolves, with more pronounced manes, and are usually brownish, reddish or tawny in colour.
The wolves of arid southern Asian countries are smaller, longer-legged and scrawnier than northern wolves. They tend to live in pairs or small groups of up to four individuals, similar to coyotes, and only form packs to take down larger prey. These wolves tend to be less afraid of humans, and are more likely to attack, though they are less aggressive in general. It is from these subspecies that domestic dogs are believed to be descended.
Old world wolves
, Canis lupus lupus
- also known as the common wolf and forest wolf, Eurasian wolves have the largest range of any subspecies, inhabiting eastern Europe, Scandinavia and much of Russia. The size of Eurasian wolves varies greatly: European wolves tend to be smaller and leaner on average; wolves of Russia and Scandinavia are larger and more heavily built. Eurasian wolves live in moderately-sized packs, and prey mainly on elk, red deer and boar. Their howls are more melodious than those of North American wolves.
Eurasian tundra wolf
, Canis lupus albus
- one of the largest subspecies of wolf, tundra wolves can reach up to two metres (7 feet) long including the tail, and also tend to be longer-lived than most subspecies with a captive lifespan of around 16 years. They live in small packs, usually numbering 4 to 6 individuals, in the northern boreal forests and tundra of Russia and eastern Scandinavia. They prey primarily on deer species, such as red deer, reindeer and elk, as well as European bison and musk oxen.
, Canis lupus chanco
- the Tibetan wolf, also known as the wooly wolf or Chinese wolf, is a relatively small, short-legged subspecies that ranges from Turkestan to Mongolia. Like most southern Asian subspecies, Tibetan wolves don't form true packs; they live and hunt in pairs, or occasionally groups of up to four individuals. They feed primarily on small mammals, such as hares, as well as Tibetan gazelle and sheep. Some scientists speculate that Tibetan wolves could be the ancestors of domestic dogs, due to their small size and the shape of the jaw.
, Canis lupus campestris
- also called the Caspian Sea wolf, the Steppe wolf is average in size, though somewhat smaller than the Eurasian wolf, and is native to the Caspian steppes. They live in small packs but may hunt individually when prey is scarce, and feed mainly on herd animals, rodents and fish. They are typically rusty grey, brownish or blackish in colour, with short, coarse fur. These wolves have been hunted for years as pests, and are now critically endangered.
, Canis lupus pallipes / Canis indica
- it is currently under debate whether the Indian wolf is a subspecies of Canis lupus
or its own species, Canis indica
. Indian wolves are one of the smallest types of wolf, averaging about 3 feet in length, with short, coarse fur that remains long on their backs throughout the year to protect their skin from solar radiation. They feed mainly small undulates, hares and rodents. Their packs are small and loose, similar to coyotes. They are typically less territorial than other wolves and rarely howl. They are found throughout the Middle East, with scattered populations in India.
, Canis lupus italicus
- an endangered subspecies, Italian wolves are also known as Apennine wolves, and are of average size, with narrow heads and long muzzles. They feed primarily on small to medium-sized mammals, such as wild boar, roe deer, red deer and chamois. Their packs are small, usually numbering between two and seven individuals. These wolves are native to the Italian Peninsula, and currently inhabit the mountainous areas of the Apennines and western Alps.
, Canis lupus signatus
- Iberian wolves are average in size and tend to be lighter-built than Eurasian wolves, with dark, reddish-brown fur; they usually have clear white markings on their lips and dark marks on the tail and legs. These wolves live in relatively small packs and are valued for their control over populations of wild boar, though they also prey on various deer species, and domesticated animals such as sheep and dogs. Their range spans the forests and plains of northern Portugal and northwest Spain.
- Canis lupus arabs
- a small, lightly-built and long-legged desert wolf, Arabian wolves live and hunt in pairs or small groups of up to four wolves, occasionally forming loose packs of up to twelve individuals to take down larger prey. They usually feed on hares, rodents and ungulates, and will also prey upon domesticated livestock. These wolves once populated the entire Arabian Peninsula, but are now found only in small pockets throughout their historical range.