Mountain Goat — The Mountain Goat (Oreamnos americanus), also known as the Rocky Mountain Goat, is a large hoofed mammal found only in North America. Despite its name, it is not a true goat, as it belongs to a different genus. It resides at high elevations and is a sure-footed climber, often resting on rocky cliffs that predators cannot reach.
The mountain goat is an even-toed ungulate of the order Artiodactyla and the family Bovidae that includes antelopes and cattle. It belongs to the subfamily Caprinae, along with thirty-two other species including true goats, sheep, the chamois and the musk ox. The mountain goat is the only species in the genus Oreamnos. The name Oreamnos is derived from the Greek term oros (stem ore-) ‘mountain’ (or, alternatively, oreas ‘mountain nymph’) and the word amnos ‘lamb’.
Both male and female mountain goats have beards, short tails, and long black horns, 15-28 cm in length, which contain yearly growth rings. They are protected from the elements by their woolly white double coats. The fine, dense wool of their undercoats is covered by an outer layer of longer, hollow hairs. In warmer seasons, mountain goats moult by rubbing against rocks and trees, with the adult billies (males) shedding their extra wool first and the pregnant nannies (females) shedding last. In the winter, their coats help them to withstand temperatures as low as -50 Fahrenheit (-46 Celsius) and winds of up to 100 mph (161 km/h).
A billy stands about one meter (3’3”) at the shoulder. Male goats also have longer horns and a longer beard than nannies. Mountain goats typically weigh between 45 and 136 kg (100 – 300 lb.); females are usually 10-30% lighter than males.
The mountain goat’s feet are well-suited for climbing steep, rocky slopes, sometimes with pitches of 60 degrees or more, with inner pads that provide traction and cloven hooves that can spread apart as needed. Dewclaws on the back of their feet also help to keep them from slipping.
Females can be very competitive and protective of their space and food sources. They will fight with one another for dominance in conflicts that can ultimately include all the females in the herd. In these battles, nannies will circle each other with their heads lowered, showing off their horns. As with fights between billies during breeding season, these conflicts can occasionally lead to injury or even death, but they are largely harmless. To avoid fighting, an animal may show a posture of non-aggression by stretching low to the ground.
Although they have gained notoriety for their shows of aggression, mountain goats spend most of their time quietly grazing. Their diet includes grasses, herbs, sedges, ferns, moss, lichen, twigs and leaves from the low-growing shrubs and conifers of their high-altitude habitat.