Gestation takes about six months. In Kenai Fjords, pregnant females make their way down steep cliffs to the sea to give birth. Nannies find secluded beaches with surrounding territory that only a goat could scale. Nannies give birth to one kid, and rarely to twins, that is ready to ascend the steep cliffs 10 to 14 days after birth. Once the nanny and her kid are back in the mountains, they will group together with other nannies and kids forming bands of 5-20 animals. Billies are never found in these bands and are generally loners outside of the rutting season.