Both sexes mature at about 5 meters long. There is thought to be a sex ratio of 67% males to 33% females. Little is known about the reproduction of this species because there does not seem to be a specific breeding season. The whales breed and calves are born all year round. The average lifespan is at least 35 years (http://www.ims.usm.edu/~musweb/ziphcav.htm. Minasian et al. 1984, Watson 1981).