Mountain Goat - Life Cycle and Mating

Life Cycle and Mating

In the wild, mountain goats usually live twelve to fifteen years, with their lifespan limited by the wearing down of their teeth. In zoos, however, they can live for sixteen to twenty years.

Mountain goats reach sexual maturity at about thirty months. Nannies in a herd undergo synchronized estrus in late October through early December, at which time males and females participate in a mating ritual. Mature billies will stare at nannies for long periods, dig rutting pits, and fight each other in showy (though occasionally dangerous) scuffles. Young billies sometimes try to participate, but they are ignored by nannies; nannies will also sometimes pursue inattentive billies. Both males and females usually mate with multiple individuals during breeding season, although some billies try to keep other males away from certain nannies. After the breeding season is over, males and females move away from each other, with the adult billies breaking up into small bands of two or three individuals. Nannies form loose-knit nursery groups of up to 50 animals.

Kids are born in the spring (late May or early June) after a six month gestation period. Nannies give birth, usually to a single offspring, after moving to an isolated ledge; post-partum, they lick the baby dry and ingest the placenta. Kids weigh a little over 3 kg (7 lb) at birth and begin to run and climb (or attempt to do so) within hours. Although they are mostly weaned within one month, kids follow their mothers closely for the first year of life (or until the nanny gives birth again, if this does not occur the next breeding season); nannies protect their young by leading them out of danger, standing over them when faced by predators, and positioning themselves below their kids on steep slopes to stop free falls.