Mountain Goat, Oreamnos americanus

The mountain goat (Oreamnos americanus), also called the Rocky Mountain goat is only found in North America. Even though it is a goat in name, it is not in the Capra genus of true goats. It belongs to the subfamily Caprinae, which holds goat-antelopes which holds thirty-two other species. It is in the family Bovidae that holds other creatures such as cattle, antelopes, and gazelle. It is the only species in the Oreamnos genus. The mountain goat is listed as of “least concern” by the IUCN.

The mountain goat lives in the Rocky Mountains and Cascade Range regions of North America. Its range extends from northern Washington to British Columbia, and Montana to Alberta. Its northern range includes the Yukon and southeastern Alaska. The southern range of this goat is extensive, reaching places such as Texas, Colorado, and the Olympic Peninsula of Washington, although they are not native to these areas.

Primarily an alpine and subapine species, the mountain goat will inhabit areas at elevations of up to 13,000 feet or more, although in coastal regions they have been known to move into lower habitats at sea level. The mountain goat prefers to stay above the tree line, and can often be seen navigating precarious mountains. They will move through forested areas in warmer weather in order to migrate to mineral licks and mate.

Each mountain goat, both male and female, has beards, short tails, white fur, and black horns that can reach eleven inches in length. The horns have growth rings for every year that the goat is alive. Males are usually larger than females, but the average weight for a mountain goat is between one hundred to three hundred pounds. The wooly coat of the mountain goat allows it to survive temperatures as cold as −50 °F. During the warmer months, the goat’s coarse outer fur and inner thick, wooly fur is shed by rubbing up against rocks and trees. The hooves of the mountain goat are cloven and in between each “toe”, there is a pad that gives the goat traction and allows it to navigate slopes than can reach a sixty-degree angle.

Mountain goats are particular in their movements, and each individual goat may vary in movement pattern. Factors like safety, hunger, temperature control, and the need for rest affect their travel. These goats will also move about seasonally, depending on whether they need extra nutrition from places with natural salt licks, mating season, and climatic factors. Mountain goats that are dispersing are typically the goats that travel the farthest distances. The mountain goat is an herbivore, and will feed on sedges, herbs, grasses, lichen, twigs, moss, ferns, leaves from low shrubs, and conifers that are in higher altitudes.

Females that are able to mate, called nannies, will perform a mating ritual between the months of October and early December. They attract males, called billies, who will show off their fighting skills, dig holes in the ground, and stare at the females for long periods of time. Occasionally a young billy will try to attract a female, but they are ignored. Mountain goats do not mate exclusively, but males will sometimes attempt to keep other males away from particular nannies. Once breeding season is over, nannies and billies will separate, forming individual groups. Males will form groups of two or three while females will form “nursery” groups of up to fifty goats. Mountain goats can live to be 15 years old in the wild, while in captivity they may be able to live for up to twenty years.

Baby mountain goats, known as kids, will be born between the months of late May or early July weighing in at seven pounds. Each nannie will typically have one baby in an isolated area, after which they will lick the kid clean and dry and ingest the placenta. Although kids are weaned at one month of age, they will remain with their mother for up to one year, or until the mother gives birth to another kid. Nannies will protect their babies by standing over them when a predator is near, by standing under them when on ledges to save them from falling, and by leading them away from danger.

Nanny mountain goats tend to be very aggressive with each other when it comes to food sources and personal space. As with male goats, female goats will battle with each other and can sometimes be injured or killed, although this is rare. In an instance of submission, mountain goats will cower on the ground. This aggression can be used when predators are involved, especially if the nanny goat has a kid. Predators including bears, lynx, cougars, wolverines, and wolves are common, and mother goats will even protect their young kids from the threat of golden eagles. Aggression in female goats has been directed towards the bigger, yet more docile, bighorn sheep. Mountain goats have been aggressive towards humans as well, and there has been one documented incident of this resulting in a human death. The wool of the untamed mountain goat has not been commercialized, although pre-Columbian Indigenous peoples of the Pacific Northwest Coast did collect molted fur to be used in their clothing.

Image Caption: Mountain Goat (Oreamnos americanus). Credit: Dave Grickson/USFWS/Wikipedia