The mountain goat (Oreamnos americanus), also known as the Rocky Mountain goat, is a large-hoofed mammal found only in North America. Despite its vernacular name, it is not a member of Capra, the genus that includes the wild goat, Capra aegagrus, from which the domestic goat is derived. A subalpine to alpine species, it is a sure-footed climber commonly seen on cliffs and ice.
The mountain goat is an even-toed ungulate of the order Artiodactyla and the family Bovidae that includes antelopes, gazelles, and cattle. It belongs to the subfamily Caprinae (goat-antelopes), along with 32 other species including true goats, sheep, the chamois, and the muskox. 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".
General appearance and characteristics 
Both male and female mountain goats have beards, short tails, and long black horns, 15–28 cm (5.9–11 in) 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 spring, mountain goats moult by rubbing against rocks and trees, with the adult bucks (males) shedding their extra wool first and the pregnant does (females) shedding last. In the winter, their coats help them to withstand temperatures as low as −50 °F (−46 °C) and winds of up to 100 mph (160 km/h).
A buck stands about 1 m (3.3 ft) at the shoulder to the waist and can weigh considerably more than the female (around 30% more in some cases). Male goats also have longer horns and longer beards than females. Mountain goats can weigh between 45 and 140 kg (99 and 310 lb), though even males will often weigh less than 82 kg (180 lb). The head-and-body length can range from 120–179 cm (47–70 in), with a small tail adding 10–20 cm (3.9–7.9 in).
The mountain goat's feet are well-suited for climbing steep, rocky slopes, sometimes with pitches of 60° or more, with inner pads that provide traction and cloven hooves that can be spread apart as needed. Also, the tips of their feet have dewclaws that are sharp to keep them from slipping.
Range and habitat 
The mountain goat inhabits the Rocky Mountains and Cascade Range regions of North America, from Washington, Idaho and Montana through British Columbia and Alberta, into the southern Yukon and southeastern Alaska. Its northernmost range is said to be along the northern fringe of the Chugach Mountains in southcentral Alaska. Introduced populations can also be found in such areas as Idaho, Wyoming, Utah, Nevada, Oregon, Colorado, Texas, South Dakota and the Olympic Peninsula of Washington.
Mountain goats are the largest mammals found in their high-altitude habitats, which reach elevations of 13,000 feet (4,000 m) or more. Although they sometimes descend to sea level in coastal areas, they are primarily an alpine and subalpine species. Throughout the year, the animals usually stay above the tree line, but they will migrate seasonally to higher or lower elevations within that range. Winter migrations to low-elevation mineral licks often take them several kilometers through forested areas.
Movement patterns 
Daily movements by individual mountain goats are primarily confined to areas on the same mountain face, drainage basin, or alpine opening. Daily movements reflect an individual’s needs for foraging, resting, thermoregulation and security from predators or disturbance. Seasonal movements primarily reflect nutritional needs (e.g., movements to and from mineral licks/salt lick), reproductive needs (i.e., movement of pre-parturient females to “kidding” areas; movement to rutting areas), and climatic influences (i.e., movement to areas in response to foraging conditions). In general, seasonal movements are likely to exhibit a strong elevational component, whereby lower, forested elevations are used during the spring-summer (security cover effects) to access lower elevation mineral licks, and during winter (thermal cover effects) to access forage. The farthest movements are expected to be by dispersing mountain goats. Such movements are likely to involve mountain goats crossing forested valleys as they move between mountain blocks.
Mountain goats are herbivores and spend most of their time grazing. Their diets include grasses, herbs, sedges, ferns, mosses, lichens, and twigs and leaves from the low-growing shrubs and conifers of their high-altitude habitat.
In captivity, the mountain goat's diet can also include grain, alfalfa, fruits, and vegetables.
Life cycle and mating 
In the wild, mountain goats usually live 12 to 15 years, with their lifespans limited by the wearing down of their teeth. In zoos, however, they can live for 16 to 20 years.
Mountain goats reach sexual maturity at about 30 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 kid 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 freefalls.
Aggressive behavior 
Nannies 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 nannies 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 nonaggression by stretching low to the ground.
In lower regions below the tree line, nannies also use their fighting abilities to protect themselves and their offspring from predators. Predators, including wolves, wolverines, lynx and bears, will attack goats of most ages given the opportunity. However, the cougar is perhaps the primary predator, being both powerful enough to overwhelm the largest adult goats and uniquely nimble enough to navigate the rocky ecosystem of the goats. Though their size protects them from most potential predators in higher altitudes, nannies still must defend their young from golden eagles, which can be a major predatory threat to kids. Nannies have even been observed trying to dominate the more passive but often heavier bighorn sheep that share some of their territory.
Mountain goats can occasionally be aggressive towards humans, with at least one reported fatality resulting from an attack by a mountain goat.
Although the mountain goat has never been domesticated and commercialized for their wool, pre-Columbian indigenous peoples of the Pacific Northwest Coast did incorporate their wool into their weaving by collecting spring moulted wool left by wild goats.
See also 
- Festa-Bianchet, M. (2008). Oreamnos americanus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 5 April 2009. Database entry includes a brief justification of why this species is of least concern.
- Mountain Goat. Oreamnos americanus. animals.nationalgeographic.com. Retrieved on: December 29, 2007.
- Oreamnos americanus. Animal Diversity Web. Retrieved on 2012-07-24.
- Burnie D and Wilson DE (Eds.), Animal: The Definitive Visual Guide to the World's Wildlife. DK Adult (2005), ISBN 0789477645
- "Mountain Goats". North Cascades National Park Service Complex. National Park Service. Retrieved 21 October 2010.
- Hiker killed by mountain goat in Olympic Nat'l. Park. seattlepi.com (2010-10-16). Retrieved on 2011-09-15.
- Mountain Goat. Yukon Govt. Env.gov.yk.ca. Retrieved on 2012-07-24.
- Media related to mountain goat at Wikimedia Commons
- A.W.F. Banfield (1974). The Mammals of Canada. University of Toronto Press. ISBN 0-8020-2137-9
- D. Chadwick (1983). A Beast the Color of Winter – The Mountain Goat Observed. Sierra Club Books. San Francisco. 208 p.
- Loyal J. Johnson (1994) Alaska Department of Fish & Game
- US Forest Service – Oreamnos americanus