Voice
Wolves make four types of sounds: howl, bark, whimper, and growl.
Howling is the most familiar wolf vocalization to everyone. When wolves howl together they harmonize, rather than howl the same note, creating an impression of more animals howling than actually are. Wolves don't need to stand to howl. They can howl lying down or sitting. Apparently, wolves howl to assemble the pack, especially before and after the ®hunt¯; to pass on an alarm, especially at the den site; to locate each other in a storm or in unfamiliar territory; and to communicate across great distances. There is no evidence that ®wolves¯ howl at the moon, or more frequently during a full moon.
Wolves only infrequently bark, and it is a quiet "woof" more often than a ®dog¯-type bark. They do not bark continuously like ®dogs¯ but woof a few times and then retreat, as for example when a stranger approaches the den. Barks reported from the field are associated with a pack's being surprised at its den and an animal, usually the female, rising to bark a warning.
Growling is heard during food challenges and, like the bark, is part of threat behavior or an assertion of rights in some social context. Growling is more common among ®pups¯ when they're playing. Pups also growl when they jerk at the ruff of a reclining adult, and comically will even try to growl adults off a piece of food. Another type of growl is a high-pitched one that begins to sound like a whine and often precedes a snapping lunge at another wolf.
Perhaps the most interesting sounds are the whines and high-pitched social squeaks associated with greeting, feeding the pups, play, pen pacing and other situations of anxiety, curiosity, and inquiry. They are the sounds of intimacy.