Mountain Goat

Oreamnos americanus

Summary 2

The mountain goat (Oreamnos americanus), also known as the Rocky Mountain goat, is a hoofed mammal endemic to North America. A subalpine to alpine species, it is a sure-footed climber commonly seen on cliffs and ice.

Despite its vernacular name, it is not a member of Capra, the genus that includes all other goats, such as the wild goat, Capra aegagrus, from which the domestic goat is derived.

Both billy (male) and nanny (female)[2] mountain goats have beards, short tails, and long black horns, 15–28 cm (5.9–11.0 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. Mountain goats molt in spring by rubbing against rocks and trees, with the adult billies shedding their extra wool first and the pregnant nannies shedding last. Their coats help them to withstand winter temperatures as low as −50 °F (−46 °C) and winds of up to 160 kilometres per hour (99 mph).

Close-up of head
A billy stands about 1 m (3.3 ft) at the shoulder to the waist and can weigh considerably more than the nanny (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 309 lb), and billies will often weigh less than 82 kg (181 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).[3][4][5]

The mountain goat's feet are well-suited for climbing steep, rocky slopes with pitches exceeding 60°, with inner pads that provide traction and cloven hooves that can spread apart. The tips of their feet have sharp dewclaws that keep them from slipping. They have powerful shoulder and neck muscles that help propel them up steep slopes.[6]

The mountain goat inhabits the Rocky Mountains and Cascade Range and other mountain regions of the Western Cordillera 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, South Dakota, and the Olympic Peninsula of Washington.

Mountain goats are the largest mammals found in their high-altitude habitats, which can exceed elevations of 13,000 feet (4,000 m). They sometimes descend to sea level in coastal areas although they are primarily an alpine and subalpine species. The animals usually stay above the tree line throughout the year 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.[7]

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.

A mountain goat grazing at Mount Rushmore, South Dakota
In captivity, the mountain goat's diet can also include grain, alfalfa, fruits, vegetables and grass.

Sources and Credits

  1. (c) Tom Benson, some rights reserved (CC BY-NC-ND), https://www.flickr.com/photos/40928097@N07/14499262251/
  2. Adapted by calgaryzoo from a work by (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Oreamnos_americanus

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