Mountain goat
The mountain goat (Oreamnos americanus), also known as the Rocky Mountain goat, is a cloven-footed mammal that is endemic to the remote and rugged mountainous areas of western North America. A subalpine to truly alpine species, it is a sure-footed climber commonly seen on sheer rock faces, near-vertical cliffs and icy passages. Mountain goats generally avoid venturing down into lower elevations—except during seasonal food shortages or during particularly bad weather—as the extreme elevation which they inhabit is their primary defense against predators such as black and brown bears, pumas and wolves.
For other uses, see Mountain goat (disambiguation).Despite its vernacular name and both genera being in the same subfamily (Caprinae), the mountain goat is not a member of Capra, the genus that includes all true goats (such as the wild goat (Capra aegagrus), from which the domestic goat is derived); rather, it is more closely allied with the other bovids known as “goat-antelopes”, including the European chamois (Rupicapra), the gorals (Naemorhedus), the takins (Budorcas) and the serows (Capricornis), of Japan and eastern South Asia.
Classification and evolution
The mountain goat is an even-toed ungulate of the order Artiodactyla and the family Bovidae (along with antelopes, gazelles, and cattle). It belongs to the subfamily Caprinae, along with true goats, wild sheep, the chamois, the muskox and other species. The takins of the Himalayan region, while not a sister lineage of the mountain goat, are nonetheless very closely related and almost coeval to the mountain goat; they evolved in parallel from an ancestral goat. Other members of this group are the bharal, the true goats, and the Himalayan tahr. The sheep lineage is also very closely related, while the muskox lineage is somewhat more distant. The mountain goats probably diverged from their relatives in the late Tortonian, some 7.5 to 8 million years ago.
Given that all major caprine lineages emerged in the Late Miocene and contain at least one but usually several species from the eastern Himalayan region, their most likely place of origin is between today's Tibet and Mongolia or nearby. The mountain goat's ancestors thus probably crossed the Bering Strait after they split from their relatives, presumably before the Wisconsinian glaciation. No Pliocene mountain goats have been identified yet; the known fossil record is fairly recent, entirely from North America, and barely differs from the living animals. In the Pleistocene era, the small prehistoric mountain goat Oreamnos harringtoni lived in the southern Rocky Mountains. Ancient DNA studies suggest that this was the sister species of the living mountain goat, not its ancestor; consequently, the living species would also date back to the Pleistocene at least.[2][3]
The mountain goat is the only living species in the genus Oreamnos. The name Oreamnos is derived from the Greek term ὄρος óros (stem ore-) meaning "mountain" (or, alternatively, oreas "mountain nymph") and the word ἀμνός amnós meaning "lamb".
Aggressive behavior
Nannies can be very competitive and protective of their space and food sources. They fight with one another for dominance in conflicts that can ultimately include all the nannies in the herd. In these battles, nannies circle each other with their heads lowered, displaying their horns. These conflicts can occasionally lead to injury or death, but are usually harmless. To avoid fighting, an animal may show a posture of nonaggression by stretching low to the ground.
In regions below the tree line, nannies use their fighting abilities to protect themselves and their offspring from predators. Predators, including wolves, wolverines, lynxes, and bears, attack goats of most ages given the opportunity. The cougar, or mountain lion, is perhaps the primary predator, being powerful enough to overwhelm the largest adults 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 must sometimes defend their young from both bald and golden eagles,[12] which can be a predatory threat to kids.[5] Nannies have even been observed trying to dominate the more passive, but often heavier bighorn sheep that share some of their territory. In 2021, a mountain goat gored a grizzly bear to death in Yoho National Park, British Columbia.[13]
Mountain goats introduced in the 1920s into Washington’s Olympic Mountains were in time found to be a nuisance there, in particular while seeking human urine and sweat for its salt content, the park lacking natural salt licks, and even aggressively approaching human visitors. One such goat killed a hiker in 2010.[14] Officials finally chose to eradicate them from the Olympic Peninsula, removing hundreds, mostly by capturing them and relocating them to the Cascade Mountains.[15]