Reproduction
Females reach sexual maturity at 6 years of age, males reach sexual maturity at 10 years of age. The male stays until  the female acts aggressively and will give out a call when approaching her. The male blocks the way of the female while wailing loudly if the she tries to leave his territory. When ready to mate the female curls her tail and gets into a stiff stance during the half hour period. The pair will stay together for about 10 days  before they part different ways. Gestation occurs around 16–18 months. A single calf is born and usually weighs about 140 pounds.