The Cry Wolf Project
The Cry Wolf Project
A pack of light gray and black wolves in snow, several with heads raised mid-howl and others lying down, seen through a spotting scope.

Wolf dictionary

Gray wolf

Canis lupus

Sometimes the best way to start understanding wolf communication is simply to listen.

12 entries

  1. 01

    Howl

    Howls exhibit various forms and may be flat, rising, falling or undulating in pitch, sometimes with breaks or modulations. Much like humans recognize callers by their voices on the phone, wolves likely discern each other through their unique howls. This recording showcases diverse howl types.

    Frequency
    Spanning pitches from 150 to 1000 hertz, commencing around 350 hertz (middle F on a piano).
    Duration
    Typically 1 to 10 seconds.
    Function
    Locating pack members, identifying themselves on the landscape, attracting mates, and expressing aggression, distress and social status; some observations suggest howls may convey mourning for a lost pack member.
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  2. 02

    Close-range howl

    Many wolf howls have far less volume than the high-powered ones we can hear from miles away. These close-range howls are like "contact calls" to pack members in the vicinity of the howling wolf.

    Duration
    Often two seconds or less.
    Function
    Contact call to nearby pack members.
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  3. 03

    Chorus howl

    One wolf starts howling and is gradually joined by other pack members until several or all are howling together. Choruses often include growls, barks, squeaks, yip-yaps and "woa-woa" howl patterns that give each pack its own signature. Wolves can estimate how many wolves are howling in a rival pack; if outnumbered they typically leave the area, and if not, they often approach.

    Duration
    On average, a chorus howl lasts approximately 70 seconds.
    Function
    Strengthens social bonds within the pack and conveys territorial messages to neighboring packs; during the breeding season, also used to communicate with pups.
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  4. 04

    Bark

    Wolves bark in stressful contexts, for example near a rival pack or a competing predator such as a grizzly bear or cougar. Competitive barks are often emitted by the dominant individual, often with dominance displays (e.g. tail held high); combative barks are only emitted in conflict with other packs, humans, cougars or bears; woofs are often directed at humans.

    Function
    Wolves may use different types of barks to identify different threats.
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  5. 05

    Growl

    Growling is a low-frequency signal with variable sequences of growls and pauses. It includes variations like snarls, brief exhalations and courtship growls, possibly reflecting different arousal levels. Short exhalations also occur during non-mating-season play between the reproductive pair.

    Frequency
    Low frequency.
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  6. 06

    Whine

    Whines, whimpers and yelps are harmonic sounds that can incorporate separate whistle sounds, known as biphonation. According to Mech (1970), wolf pups begin making vocalizations such as whines and moans a few days after birth, and start howling at around one month of age.

    Frequency
    A mean fundamental frequency of around 500–600 Hz.
    Duration
    From tenths of a second to 1 second.
    Function
    Observed in agonistic, mating and other social interactions, often associated with submissive behavior.
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  7. 07

    Whimper

    Whimpers are brief, whine-like sounds produced in successive bursts, in the same situations as whines. They are shorter than whines and have lower whistle frequencies.

    Function
    Used when a wolf is soliciting help or in distress.
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  8. 08

    Moan

    Moans are lower in pitch than whines and occur in agonistic, mating and other social contexts. They may indicate some distress, but unlike whimpers they are not used to solicit help; in human terms, complaining without expecting sympathy.

    Frequency
    Fundamental frequencies ranging from 50 to 500 Hz.
    Duration
    Fractions of a second to a few seconds.
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  9. 09

    Yelp

    Yelps are brief, high-pitched, loud harmonic sounds emitted during agonistic interactions, always with submissive behavior. One type, described by Vicente Palacios in Iberian wolves and also recorded by us in Yellowstone wolves, is a series of short, frequency-modulated yelps that sounds like laughing hyenas. In this recording you will hear a yelp in response to snarls from another wolf.

    Function
    Seemingly to deter or halt an ongoing attack, or to pacify a dominant, aggressive pack mate, although there is no systematic data to fully confirm this.
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  10. 10

    Woa

    A crucial element of chorus howls, the "woa call" is a loud, prolonged signal. Wolves keep their mouths wide open with lips retracted throughout, and can give both continuous and discontinuous woa calls.

    Frequency
    Higher pitch and frequency modulation than howls, as judged by hearing.
    Function
    Fosters more interaction among group members than regular howling, with frequent changes in body position.
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  11. 11

    Who

    A very soft, close-range call made by wolves.

    Function
    Unknown.
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  12. 12

    Teeth-clacking

    Teeth-clacking is a "warning bite-intention signal. The wolf snaps at the air close to its adversary and does not actually bite."

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Wolves have a rich vocal repertoire: yelps, whines, moans, growls, woofs, barks and their iconic howls. These sounds serve many purposes, from defending territory to locating pack members to sending alarms. But little is still known about all of the sounds they make or the meaning of them from a wolf’s perspective. Their howls vary a great deal, and wolves sometimes combine two different sounds, such as howls and barks, into calls with nuanced, context-dependent functions. Because wolves live in social packs, they often weave several of these sounds into a chorus howl (or “rally”), with multiple wolves vocalizing at once in a crescendo-like group call.

We already understand a lot about wolf vocalizations. The Cry Wolf Project is using AI and science to dig deeper into what they mean.

How to listen

Just as when learning a new human language, start with the basic sounds. Play each entry above, then listen for the same sounds in the field, in videos online, or on our YouTube channel. A spectrogram shows the pitch and duration of a sound as a picture, and the video dictionary of wolf sounds beside the introduction pairs each call with its spectrogram so you can learn to see and hear the differences.

Credits

Recordings by The Cry Wolf Project. Descriptions draw on the published literature on wolf vocal behavior, including Mech (1970) and Vicente Palacios’s work on Iberian wolves. With deep gratitude to the scientists of Yellowstone National Park’s Wolf Project, and to the researchers, collaborators and citizen scientists around the world (meet the team) who help us listen.

Sources and credits

  1. Mech (1970), as cited on the Languages of Life wolf page
  2. Vicente Palacios, research on Iberian wolf vocalizations