Barking is also more common in domestic dogs than in their canine wolf cousins. This is particularly true for dogs that are the result of selective breeding, where the barking trait was promoted by those who wished to use their dogs as alarms and guards.
Domestic dogs usually make short, sharp barking sounds whenever they are excited. The tone of the bark conveys a meaning: High barks are for greetings, as when welcoming your return home; prolonged and frantic yelps often convey pain and distress; deep barks are intended to warn and to alert you to a threat; and deeper barks are indicative of aggression and threat. It becomes a clearer message when growling is woven into the deeper barks.
Wolves, on the other hand, generally do not bark to communicate with each other. Being hunters themselves, wolves bark only when necessary, such as when warning their pack members or pups of the approach of a threat. Even then, it is a last resort, as the wolf does not wish to bring attention to its location. The bark is typically a one time short and quiet "woof".
One of the more obvious sounds that wolves have held onto over time is the howl. Wolves howl much more than dogs and every wolf has a distinct howl, which suggests that wolves can be distinguished from other wolves by their howls – much in the way humans recognize each other by voice. A wolf’s howl is a long lasting tone of 2-11 seconds, with possible fluctuation over some notes. Wolves have been observed to use their howls for several reasons: when reassembling after dispersal, confirming territory, and in celebration, amongst other reasons. They may howl alone or in chorus with other wolves.
While most dogs do not howl as much as wolves, there are some northern breeds, such as huskies, malamutes and hounds that still do. Some have observed that huskies and malamutes will tend to howl after being left alone by their owners. Perhaps they are using it as a way of expressing their loneliness. Some breeds appear to want to “sing” along, howling when they hear certain sounds or when they hear their humans singing. For as far removed our domestic companions may be from the wolf cousins, the joy of creating and joining a chorus has not left many of them.
Image: hernan.mojaro / via Flickr