Wolves howl for many of the same reasons that other species use vocalizations: to warn others about predators, to defend their territories, and to find mates.
There are a number of factors that can influence how and when wolves howl, such as time of day, which way the wind is blowing, and even different weather conditions such as the presence of fog or rain. Wolf howls are specific vocalizations used both within a pack and between packs in the same geographic area. These low-frequency sounds have been heard at distances of nearly 10 miles away, although the presence of trees, mountains, and other geographic features can decrease that range.
While wolves have been studied both in captivity and in the wild, scientists continue to learn about their communication and how hunting and habitat destruction by humans may be changing their behavior.
Here, we’ve gathered everything we know about why wolves howl.
Like many other species of animals, wolves use vocalizations to communicate. When wolves become separated, they will howl to locate the other members of their pack.
Both individuals and entire packs may howl to find a missing member. The vocalization is also frequently used to locate missing pups or by adults to let the pups know that they are on their way home from foraging.
Research on wolf behavior has looked into whether howling to communicate location is harmful to wolves that are in danger of being detected and hunted by humans, but so far no connection has been found.
Wolf howling between packs increases dramatically during mating season. When hormones are surging, wolves are more likely to show aggressive behavior towards members of other packs in order to defend their territory and the females in their pack. Wolves’ average summer home ranges span 72 square miles, and territorial howling serves as a warning to outsiders to keep their distance.
According to a study by scientists at the Wolf Science Centre in Austria, wolves tend to howl more if they are separated from another wolf that they have a close relationship with.
In the past, scientists had hypothesized that wolves howled as a stress response to being separated from pack members. However, European researchers found that levels of a stress hormone called cortisol did not significantly increase in pack members when a wolf was taken away from them. Instead, it seems that wolves howl when separated from another wolf simply to make contact with them and not because their absence is stressful. The higher the rank of the missing wolf, the more the rest of the pack howled.
Wolves normally hunt in packs, so it’s important that every member knows what they should be doing at all times during a hunt. Howling is one way to communicate plans and strategy during a hunting session so that no one is left behind and the hunt is successful.
Eligible wolves must find a mate when the time is right. In the weeks leading up to the breeding season, single wolves will use howling to advertise that they are looking for a mate. By howling as an individual and not as part of the pack, a wolf can be recognized by others as available, attractive, and interested in breeding.
Once wolves have paired, they will stay together until one of the members of the pair dies, at which point the surviving member will find a new mating partner.
What about that classic picture of a wolf howling up at the moon? Do wolves specifically howl when the moon is out?
Wolves are generally nocturnal animals, but they can also be active during crepuscular hours (dawn and dusk). Because of this, a wolf will most likely be observed howling to communicate during times when the moon is out and in a visible phase. The myth that wolves howl at the moon most likely started because of this nighttime behavior, which would be easier to observe under the light of a full moon.
However, there is no scientific evidence that wolves howl more under a full moon than when the moon is in any other phase.