Why Do Wolves Howl? What Wolf Howls Really Mean

The main reasons wolves howl

A gray wolf pack may spread out over a territory of hundreds or even thousands of square kilometers, and pack members often travel or hunt apart. Sight and scent do not work over such distances, so wolves rely on howling, the loudest and farthest-reaching sound they make. Biologists recognize several main purposes:

• Contact: finding pack members that have become separated, for example after a chase, during a storm or while crossing unfamiliar ground.
• Rallying: gathering the pack together, often before setting off to hunt or after a rest.
• Territory: telling neighboring packs that an area is occupied, so that rival groups can avoid each other.
• Alarm: warning other pack members of danger, particularly near a den with pups.
• Social bonding: reinforcing ties within the family, especially when a close companion is absent.

Wolves also communicate with barks, growls and whines at close range, and with body language and scent marks. Howling is reserved for long-distance messages.

Howling to keep the pack together

When wolves reunite or prepare to travel, they often gather for an excited group howl, accompanied by tail wagging, nose touching and playful jostling. These rallies seem to synchronize the pack before a hunt or a long journey.

Research also shows that howling is about relationships, not just location. In a 2013 study at the Wolf Science Center in Austria, captive wolves howled more when a pack mate they had a close relationship with was led away, and when the departing wolf was high-ranking. Levels of the stress hormone cortisol did not explain the pattern, which suggests that wolves use howling flexibly to keep in touch with important companions rather than simply as a sign of distress.

Howling to defend a territory

Howling works like an acoustic fence. In classic field studies in Minnesota in the 1970s, biologists Fred Harrington and L. David Mech imitated howls near wild packs and recorded their replies. Packs were more likely to answer when they had something worth defending, such as a fresh kill or pups, while lone wolves, which have no territory, usually stayed silent.

By announcing where they are, packs can avoid running into each other unexpectedly. That matters, because fights between packs are among the main causes of death for wild wolves. Howling works together with scent marking: wolves leave urine and scratch marks along the edges and trails of their territory, which tell neighbors who lives there long after the sound has faded.

What a chorus howl means

When several wolves howl together, the result is a chorus. Each wolf howls on a slightly different, shifting pitch, so the voices harmonize rather than blend into one note. This can make a small pack sound much larger than it is, which may help deter rivals.

Individual howls carry a lot of information. Males usually have deeper voices than females, and young wolves often end their howls with a series of yelps. A howl’s basic pitch typically lies between about 150 and 780 Hz, rising and falling smoothly, with many higher overtones. Acoustic studies have shown that each wolf’s howl is distinctive enough for individuals to be identified from recordings, and that wolves from different regions have different howling styles.

How far can a wolf howl be heard?

Howls are long, steady and fairly low in pitch, which helps them travel. Under calm conditions, a howl can be heard up to about 16 km (10 mi) away across open tundra, and somewhat less in dense forest. Wind, terrain, temperature and background noise all change how far the sound carries.

Because wolves answer howls, biologists use this behavior in howling surveys. By howling themselves or playing recordings at night, researchers can locate packs, find summer gathering places known as rendezvous sites and count the high-pitched voices of pups without ever disturbing the animals.

When do wolves howl most?

Wolves howl at any time of day, but most howling happens around dusk, at night and in the early morning, when wolves are most active. Like many nocturnal animals, they travel and hunt mostly in the dark, so that is when pack members most need to find each other.

Howling also tends to follow the seasons. In many areas it increases in late winter, during the breeding season, and again in late summer and autumn, when packs gather around pups at rendezvous sites. Lone wolves that are crossing other packs’ territories usually keep quiet, which helps them avoid attacks by residents.

Do wolves howl at the moon?

No. Wolves do not howl at the moon, and there is no evidence that the phases of the moon affect how often wolves howl. The myth probably comes from the fact that wolves howl most at night, and that they raise their heads when howling, which helps project the sound over long distances. Paintings, films and Halloween images did the rest.

Hearing wolves howl is also not a sign of danger to people. It means a pack is nearby, communicating with its own members or its neighbors; see are wolves dangerous? for the real risks.

Do coyotes and dogs howl for the same reasons?

Coyotes howl too, but their calls are higher and more broken up, mixing yips, barks and quavering howls into the “group yip howl” heard at dusk across much of North America. They use these calls for contact and to announce their presence, much like wolves; learn to tell the two apart in wolf vs coyote. Domestic dogs inherited the ability to howl from their wolf ancestors, and some breeds, such as huskies and hounds, still howl readily, often in response to other howls or similar sounds like sirens.