The small, compact basenji is known as a skilled hunter and, oddly enough, a yodeler of sorts. That’s because the roughly 16-inch-tall hunting dog is perhaps best known in the world for its inability to physically bark.
The Basenji Club of America explains that this hollow-sounding yodel is caused by the unique physiology of the basenji voice box, or larynx. In most mammals, the larynx is the organ that facilitates respiration and forms an air passage from the mouth and nose to the lungs. It also holds the vocal cords that, when vibrating, produce a sound that is vital to communication.
In the basenji, the space between the vocal cords called the laryngeal ventricle is shallower than in other domestic dog species, which limits the movement of the vocal cords and creates the higher-pitched yodel heard in the basenji.
A 1965 study published in the journal Genetics and the Social Behavior of the Dog examined the genetics and behavior of various dog species over the course of 13 years. In their research, the study authors suggested that the “barklessness” observed in the basenji may be the result of its African ancestry.
“It is possible that barking, which is an alarm signal given by dogs whenever a strange animal or person approaches their home territories, is not conducive to survival in the African forests,” they wrote. “Leopards are reputably fond of dog meat, and it may be that the dog which barks simply attracts attention to himself and comes to an untimely end.”
But that’s not to say that the basenji doesn’t communicate with other dogs. Further examination of the basenji barks during the 1965 study found that the dogs communicate information through their “crowing” or “yodeling” sounds.