The Basenji is a breed of hunting dog. Basenjis, like dingoes, New Guinea singing dogs and some other breeds of dog, come into estrus only once annually—as compared to other dog breeds, which may have two or more breeding seasons every year. Both dingoes and Basenji lack a distinctive odor, and are prone to howls, yodels, and other vocalizations over the characteristic bark of modern dog breeds. One theory holds that the latter trait is the result of selecting against dogs that frequently bark—in the traditional Central African context—because barking could lead enemies to humans' forest encampments.