MOUNTAIN FAUNAS 75 
The relatively rich pasturage, and the relative 
security, account for the fact that mountains and 
plateaux have a considerable number of peculiar herbi- 
vores, especially ungulates. The ungulates of mountains 
belong to more than one group, but in the Old World 
at least the two genera of sheep (Ovis) and goat (Capra), 
which appeared late in geological time, include animals 
which are especially adapted for mountainous districts. 
Just as deer are typically forest animals, and antelopes 
typically steppe or savana animals, so sheep and goats 
are the typical inhabitants of elevated regions. In the 
case of sheep, at least, domestication has produced so 
many changes in character, that it is somewhat difficult 
to realize the extraordinary agility of the wild animals, 
and their other special adaptations to life in mountainous 
and elevated regions. The thick coat protects them 
against cold, and the fact that the young—necessarily 
few in number in animals with such a habitat—are 
able to follow the mother anywhere within a very 
short time after birth is an important adaptive char- 
acter. Like steppe animals in general, wild sheep are 
social, and like many such animals they seem mostly 
to appoint sentinels while feeding. Their powers of 
leaping are very great, and they seem able to scale 
apparently inaccessible cliffs. 
While wild sheep, like domesticated forms, chiefly 
graze upon the ground, the equally agile goats depend 
largely upon the shoots, leaves, and twigs of bushes 
and small trees, and as the trees in their native habitats 
are mostly xerophytic, it is noticeable that the goats 
have very catholic tastes, not disdaining the resinous, 
hairy, or spiny plants native to high steppes. From 
the difference in diet the goats usually occupy ground 
which is more scarped and rocky than that favoured 
