WHY DOG BARK

The popular understanding of dog barking is almost like a silly riddle: Why do dogs bark? Because they can.
But a small band of researchers around the world, trying to separate fact from speculation, are finding that dogs almost always bark for a reason, even if that reason isn't apparent to humans.
The barks has evolved into a complicated means of communication between dogs and, potentially, between dogs and people, say a group of animal behaviorists, or ethnologists, that includes Dorit Feddersen-Petersen at Christian-Albrechts-University in Kiel, Germany.
Most wild canids including wolves, dogs' nearest relatives bark as a form of close-range communication, researchers say. The wolf's bark one of a number of basic vocal sounds, including hauntingly harmonic howls is short, low-pitched and gruff, often described as "noisy" because it lacks harmonic or tonal qualities identified with more musical vocalizations. The bark is usually associated with defense of den or pups, a warning to back off, a protest, threat or an actual attack, Dr. Feddersen-Petersen said in an e-mail interview.
By comparison, dogs are virtuoso barkers, capable of flights of sonic fancy. Dog barks can be noisy, harmonic or a combination of the two, depending on their context and purpose, says Dr. Feddersen-Petersen. Last year in The Archives of Animal Breeding, an international journal, she published the results of a study comparing vocalizations in 11 European wolves and 84 dogs from nine breeds, including poodles, Weimaraners, American Staffordshire terriers, German shepherds, Alaskan malamutes, bull terriers and Kleiner Muensterlaenders.
The results, she reported, graphically portray how different barks express different emotions, including loneliness, fear, distress, stress and pleasure, as well as a need for care among puppies and serve to alert other dogs, people or animals to changing external circumstances.
"This work on barking is extremely careful and extremely important because it calls attention to the complex social life of dogs that we have barely begun to comprehend," says Marc Bekoff, an ethologist at the University of Colorado who studies canids and cognition in animals.