The Palaearctic region covers Europe, North Africa, most of the Arabian Peninsula, and Asia north of the Himalayas, including Japan and Korea. The Palaearctic is the largest of the major faunal regions in terms of its geographical area and it contains a wide range of habitats. Despite this, it has the lowest rate of endemism of all the major faunal regions. Thirteen orders and 42 families are present, none of them endemic. About 30% of the 262 genera and 60% of the 843 species that occur are endemic. The relatively low level of en-demism reflects the long periods of contact at various times with the Nearctic, Oriental, and Ethiopian regions. Around half the Palaearctic families also occur in the Nearctic region, a consequence of the intermittent existence of the Bering land bridge. About 60% of the families also occur in the Oriental region.
The Palaearctic lacks the great diversity of ungulates found in the Ethiopian region, though a few species occur, including an endemic genus of Central Asian gazelles, Pro-capra. Groups that evolved in southern Eurasia such as deer and caprins are well-represented, with members of the latter group found in virtually all the regions' mountain ranges.
Equids and camelids both arrived from North America and still survive in the Palaearctic, though the distributions of all the surviving species are greatly reduced. Przewalski's horse (Equus caballus) was last seen in the wild in the 1960s, though reintroduction projects aimed at returning it to the wild in Mongolia began during the 1990s. Two species of wild ass still survive. Kulan, or onager (E. hemionus), is widespread in Mongolia, and is still found in fragments of its former range, in western India and in Turkmenistan. Kiang, or Tibetan wild ass (E. kiang), remains numerous on the Tibetan Plateau. Wild bactrian camels are now restricted to three small areas of the Gobi and Takla Makan deserts.
A high-altitude ungulate fauna has evolved on the Qing-hai-Tibet Plateau, adapted to elevations above 13,000 ft (4,400 m) and prolonged periods of cold in winter. Component species include Tibetan antelope, or chiru (Pantholops hodgsonii), Tibetan gazelle (Procapra picticaudata), wild yak (Bos grunniens), Kiang (Equus kiang), Tibetan argali (Ovis ammon hodgsoni), and blue sheep (Pseudois nayaur) with white-lipped deer (Cervus albirostris) in the eastern third of the plateau. The diversity of these herbivores does not approach that of the East African savannas but they occurred in large numbers, with several nineteenth century travelers and sportsmen reporting vast herds of thousands of animals. These numbers have since been reduced, but in the eastern steppes of Mongolia, herds of several thousand Mongolian gazelles (Procapra gutturosa) can still be seen.
Of the smaller groups, there are 19 endemic species of pika (Ochotona) distributed through the mountains of Central Asia and the Himalayas. Two species of desmans, endemic insectivores, occur in the Pyrenees and Russia respectively. All but one of 20 species of dormice (Myoxidae) are endemic to the Palaearctic and there is a diverse assemblage of desert rodents in the region: 32 jerboas (Dipodidae), and 41 gerbils and jirds (Muridae).
In the eastern Palaearctic there are several island endemics. Japan has an endemic species of macaque (Macaca fuscata), serow (Capricornis crispus), and hare (Lepus brachyurus). The Ryukyu rabbit (Pentalagus furnessi) is endemic to two of the Ryukyu Islands.
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