The mountain goat is a compact, stocky ungulate with a heavy white coat, and a short tail 10-20 cm in length (4-8 inches) . Both male and female look similar with very muscular shoulders, short sharp horns and a beard under the chin. The coat is white but may appear grey, tan or reddish tan due to staining from dust baths. The horns, hooves and nose are black.
Coat and molt
Mountain goats have a very thick coat in winter to withstand the extremely low temperatures and high winds in the alpine. A dense inner wool is combined with long outer guard hair up to 20 cm long (eight inches). In June and July, goats shed the winter coat leaving a short summer coat. When they molt, the old winter hair is rubbed off on brush where they walk and on ground where they rest. By September 15, their winter coat is growing back.
Weight and height
Average mature male mountain goats weigh 80 to 100 kg (176 to 220 lbs), measure 165 cm (65 inches) in length and stand 101 cm (40 inches) tall at the shoulder. Average mature female mountain goats weigh 60 to 80 kg (132 to 176 lbs), measure 142 cm (56 inches) in length and stand 89 cm (35 inches) tall at the shoulder.
Horns
Average horn length for mature male and female mountain goats is 25 cm (10 inches). The horns are not shed and last a lifetime. The age of a mountain goat can be determined by counting the bands (annulus) at the base of the horns and adding 1-1/2 years – the age the annulus begin to form.
Hooves
The double split hooves have a very hard outer edge and a soft pad in the middle. The pad gives traction on hard or wet rock and ice. The hard outer edge gives traction in mud, snow or rock scree. Two back dewclaws above and behind the hoof can be used to slow the goat when going downhill.
Age
Mountain goats in the wild can live up to 14 years. Lifespan is limited by wear on the teeth from coarse feed and grit. When the teeth wear to the gum, starvation can occur.
Distinguishing sex
Males are larger than females but only by 20% to 30%. It is difficult to tell sex by size unless goats of similar age are standing close together - a rare occurence. Horns on males and females are similar enough in shape and length to make it difficult to tell sex at a distance. A better way is to watch for the anogenital patch under the tail on females in the shape of a figure eight. The male only has a small anal patch. Another way is to observe urination posture. Males stand to urinate. Females stretch, spread their legs and squat. See photo
Taxonomy
Order: Artiodacyla
Family: Bovidae
Genus: Oreamnos
Species: O. americanus
