A wolf’s size depends a lot on the subspecies of wolf and where it lives. In general, wolves that live further north are larger than wolves that live further south. Some Alaskan wolves can reach 5-6 feet long and weigh more than 120 pounds, while the wolves living in the Middle East can weigh as little as 30 pounds. Males are a bit larger than females, weighing on average about 20% more.

Wolves come in a wide range of colors from solid white through cream, tan, brown, and gray, to solid black. The majority are a grizzled gray-brown. Each individual hair has several bands of color on it, which contributes to the appearance that a wolf’s pelt is made up of thousands of specks of color (“agouti” coloration). Wolves have two layers of fur: long, waterproof outer guard hairs, and a softer undercoat which provides insulation. They shed their bulky undercoat in the spring—resulting in a fairly short-haired, svelte look during the summer—before growing it back in the fall.

The color of fur depends on subspecies and location; wolves far north will have lighter coloration meant to blend into the tundra, wolves living in forested area will typically be darker browns and grays, and southern wolves in more arid climates may have a sandier tone to them. Coat color is genetic.

Absolutely. Wolves’ strongest sense is their sense of smell, which is roughly 100 times more powerful than that of humans. A wolf can tell, from the scent-markings of another wolf, that other wolf’s age, gender, stress level, dominance, reproductive status, and even its individual identity! Wolves also have keen vision, and can see in the dark better than we can, although they can’t distinguish colors as well as we can. (In particular, like dogs, they can’t distinguish shades of red from shades of yellow and green.) They also aren’t very good at discerning small details (their visual “resolution” is rather weak), but they have a superior ability to see and process rapid movement. Wolves also have a good sense of hearing—only a bit more powerful than that of people, but able to hear much higher-pitched sounds than we can.

Wolves haves 42 teeth, which are specialized for different jobs. The canines (fangs) grasp and puncture, the molars crush, the incisors nibble and scrape, and the carnassials shear. The wolf’s jaws are extremely powerful, and they are able to generate 400 pounds of pressure per square inch!

Wolves usually travel at a trot of around 5 miles per hour, and can maintain this pace for hours at a time, but if need be a wolf can run at speeds of up to 38 mph. Wolves regularly travel great distances in search of food—up to 50 miles in a day. This is particularly true during fall and winter, once their pups have grown and the pack enters their “nomadic” phase.

Wolves have a number of sophisticated communication systems. They leave scents that other wolves can “read,” including in their urine. Wolves scent-mark with urine near the edges of their territory as a signal to other packs that the territory is occupied. A wolf will also scent-mark on top of its mate’s marking in what seems to be a sort of wolf version of a wedding ring, affirming the mated pair’s bond and advertising their union to other wolves. Wolves also have a pair of anal glands which convey information about that wolf’s mood and identity. (This is why dogs sniff one another’s rears when meeting—it’s an exchange of information!) Wolves use a large repertoire of sounds, including yelps, whines, growls, snarls, huffs, moans, and of course howls. Yelps, whines, and other high-pitched sounds are used to convey friendliness, submission, or fear, while low-pitched sounds like growls convey aggression or dominance. Submission versus dominance is also expressed through body language and facial expressions. Friendly or submissive wolves will lower their body, tuck their tail down or loosely wag their tail, flatten their ears back, and lick the face of a more dominant wolf. Aggressive or dominant wolves stand tall, and keep their ears forward and tail straight or raised. If a wolf is threatening to fight, it will also bare its teeth.

There are several different reasons. Howling is used to gather pack members together (for instance, before starting out on a hunt, or if some pack members have become separated from the others). It’s also used by packs as a territorial call, alerting nearby wolves that a pack already occupies the area. There’s also some evidence that howling may be used by wolves looking for a mate. Finally, group or “chorus” howling seems to serve a communal purpose, strengthening social bonds within the pack. Contrary to popular legend, wolves don’t “howl at the moon,” though they do raise their heads when they howl in order to project the sound farther.

Very few wild wolves live past the age of ten, and many don’t live more than five years. Around half of all pups don’t survive their first year, and even adult wolves are never far from the dangers of starvation, disease, fights with other wolves, or being injured by their prey. In captivity, where they have the benefit of veterinary care and regular meals, wolves can live into their late teens!

Wolves specialize in hunting large ungulates (hoofed mammals). Depending on the area, their prey of choice include moose, elk, deer, caribou, wild sheep, wild goats, muskoxen, saiga antelopes, bison, and wild boar. They will sometimes supplement their diet with smaller prey like beavers, hares, and fish, and will also occasionally eat fruits (though they are not true omnivores like bears). Wolves lead a feast-and-famine existence, able to go weeks without food and then gorging themselves when they succeed in catching prey (they are able to eat up to 22 pounds of meat at a time).

While single adult wolves have been known to tackle even their largest prey, most wolves hunt in packs. The packs spend much of their time looking for prey. When they locate prey, either by spotting it or catching its scent, the pack will try to stalk as close as possible to it without being seen. As soon as the prey flees, the pack races after it. (If a large prey animal stands its ground instead of fleeing, the wolves will normally give up the hunt.) If they are chasing a herd, the wolves will run among or alongside the herd, testing individuals for weakness and attempting to separate weaker members from the rest of the herd. “Weak” animals might be sick, injured, or very old or young. Once they have isolated their prey, the wolves will attack it in earnest, focusing on the rump and sides of their larger prey. The prey usually succumbs to blood loss, though wolves can kill smaller prey with a bite to the neck. Contrary to myth, wolves don’t hamstring their prey. Wolves’ main prey is often large, dangerous, fast, and alert, so, as with many predators, wolf hunts are more often than not unsuccessful. They may succeed in killing as little as one out of every ten prey animals they pursue.

Most wolves live in packs, though there are also some lone wolves, who are usually individuals searching for a mate in order to start their own pack. “Packs” in the wild are family groups, normally consisting of a breeding pair, any of their pups from that year, and often some of their grown children from one to three previous litters. In some cases packs are more complex than this, for instance if one of the breeding pair dies, the remaining parent will take a new mate to be the “stepparent” of the pack. The parents’ grown children will eventually leave their birth pack in order to find a mate and start a new pack of their own. Packs are popularly portrayed as being governed by a dominance hierarchy, with “alpha” wolves at the top, “betas” below them, and “omegas” at the bottom. However, since normal packs are just families, the hierarchy follows naturally: the “alphas” are the parents of the lower-ranking wolves, and outrank them by virtue of that fact, not because they fight with one another for dominance. Indeed, fights between pack members are very rare in the wild, and dominance challenges (challenging the dominant wolf’s authority) basically nonexistent. Ritualized displays of dominance and submission are used primarily to strengthen social bonds and prevent fights. Many wolf biologists now avoid using terms like “alpha” and “beta” when describing most wild (natural) wolf packs.
Packs can contain anywhere from two to 42 wolves, though most have somewhere between four to seven members, and packs larger than 12-15 are quite rare. Packs control exclusive territories which they defend from other packs. Territories vary in size depending on location, prey abundance, pack size, terrain features, and other factors.

Wolves take a long time to sexually mature, generally not until they are two to four years old. Once they do mature, wolves normally leave their birth pack and set out to find a mate (this is usually another wolf that has dispersed from its birth pack.) The pair-bond formed between the two is quite strong, and wolves usually have the same mate for many years at a time. However, wolves do sometimes change mates, when their old mate dies or becomes too old to reproduce, for example. The wolf mating season occurs only once a year, generally in late winter, with the exact time depending on the latitude. The wolf’s gestation period is about 63 days, so wolf pups are generally born in April or May. It’s still not certain when or if wolves grow too old to reproduce. There’s some evidence of elderly females becoming sexually inactive, but there are other cases in which wolves of 10+ years were able to mate. It’s sometimes claimed that only the “alpha” wolves in a pack mate, but this is not always true. In many cases the “alphas” are the only sexually mature wolves in the pack (since once their children reach sexual maturity they normally leave to form their own pack), and hence the alphas are by definition the only wolves to mate.

The average litter size is about six pups, who weigh around one pound each. Newborn pups have dark fur (even arctic wolves are dark-furred when they are born) and blue eyes, which will change color as they grow older. They also have stubbier, more “puglike” faces than adult wolves and small, rather droopy ears. When they are first born, the pups are blind, deaf, and completely helpless, and they spend their first several days huddling near their mother and suckling. After several weeks, they are able to see, hear, and walk around, and by a month old they begin to venture out of their den. Pups grow rapidly, and after six months they are almost indistinguishable physically from adults, though it takes them a few years to sexually mature and to learn to be expert hunters.

A phenotype is a physical aspect determined by genetics— the interaction between genes and the physical world. Wolves have unique phenotypes that are distinguishable from even domestic dogs! Here are some of the most obvious traits to look for:

• Eyes — Wolves have golden eyes. They can be light yellow to darker amber, but never blue, green, gray, or brown.

• Round ears — Wolves have ears which are short on the head and rounded at the tips. They do not have floppy or bent ears, and the insides are full of fluff.

• Forehead — Wolves have a gentle slope from forehead to muzzle, and do not possess a “stop” or a bridge to their nose. Dogs will have a dip between their eyes at the top of their muzzles; this is absent in wolves.

• Chest width — Wolves have extremely narrow chests which cause their legs to sit right underneath them. The legs are very slim and long.

• Paws — Wolf paws are very big, and are typically much wider than the leg width. They also have webbing between their toes.

• Tail — A wolf’s tail hangs straight, it does not curl at all. It also has a “bottlebrush” of fur on all sides.

Keep in mind that while there are breeds of dogs that are bred to look very similar to wolves and thus may have an approximation of some of these traits, all of these phenotypes are consistently present in full wolves.