Gray Wolf

Two forms of submissive behaviour are recognised: passive and active. Passive submission usually occurs as a reaction to the approach of a dominant animal, and consists of the submissive wolf lying partly on its back and allowing the dominant wolf to sniff its anogenital area. Active submission occurs often as a form of greeting, and involves the submissive wolf approaching another in a low posture, and licking the other wolf's face.
When wolves are together, they commonly endulge in behaviours such as nose pushing, jaw wrestling, cheek rubbing and facial licking. The mouthing of each other's muzzles is a friendly gesture, while clamping on the muzzle with bared teeth is a dominance display. Dominant wolves may assert themselves by straddling over a subordinate family member. At a kill, wolves will protect the carcass from afar from other wolves by flattening their ears outwardly, thus indicating that they are covering something belonging to them.
• Howling
Wolves howl to assemble the pack (usually before and after hunts), to pass on an alarm (particularly at a den site), to locate each other during a storm or unfamiliar territory and to communicate across great distances. Howling consists of a fundamental frequency which may lie between 150 and 780 Hz, and consists of up to 12 harmonically related overtones. The pitch usually remains constant or varies smoothly, and may change direction as many as four or five times. Wolves from different geographic locations may howl in different fashions; the howls of European wolves are much more protracted and melodious than those of North American wolves, whose howls are louder and have a stronger emphasis on the first syllable. The two are however mutually intelligible, as North American wolves have been recorded to respond to European-style howls made by biologists.