OVIS ARIES, the DOMESTIC SHEEP 32.1 the Living Animal 32.1
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CHAPTER THIRTY-TWO OVIS ARIES, THE DOMESTIC SHEEP 32.1 The Living Animal 32.1.1 Zoology Sheep, wild as well as domestic, are medium-sized bovids, and are thus even-toed ruminants with horns in both sexes. As in all bovids, the horns are hollow when shed. Sheep horns are massive and curve in the shape of a spiral around the ear with varying diameter. The horns of the ewes are always smaller than those of the rams of the same species or breed, and only slightly curved. Hornless ewes are very common in domestic breeds. The shoulder height differs between the species, and varies between 0.65 and 1.3 m; rams are larger and heavier than ewes, and the wild sheep are larger than most domestic sheep. Sheep typically have a narrow nose, pointed ears, and a long, drooping tail and never have a beard such as goats (Capra) possess. They have a face gland just below the eye. Domestic sheep lost their overcoat, expos- ing their woolly undercoat. Feral domestic sheep in time develop the coarse hairs again, but never to the degree seen in the wild species. The earliest domestic sheep most likely still had an overcoat, shedding their wool annually.1 Sheep are gregarious animals (fi g. 393) and can be easily herded in large groups. They keep their heads relatively cool by grouping together in a circle (fi g. 394) when the sun is too hot. The hierarchy between rams is based on the age and size of the horns. They fi ght amongst each other by rearing up on their hind legs, followed by lunging forward and down with lowered heads to crash their horns together, but serious injuries are rare. Domestic sheep fi ght much like their wild cousins. Domestic sheep are well adapted to the tropical, subtropical and temperate arid regions and are thus found almost everywhere; they 1 Clutton-Brock, op. cit. (1981), 22. 322 OVIS ARIES are intolerant to desert conditions and extreme humidity. Sheep are grazers, like cattle, and unlike goats, which are browsers. 32.1.2 Related Species There are two wild sheep on the subcontinent, the urial (Ovis vignei) and the argali (Ovis ammon), and a sheep-like distant relative, the blue sheep (Pseudois nayaur), all three with a very limited distribution. Wild sheep have a woolly underfur, but this is always hidden by the coarse and heavy coat. The horns of the wild sheep are more impressive than those of the domestic sheep. Hornlessness of the ewes is very rare in wild sheep. Herds of wild sheep can consist of more than a hundred individuals; rams generally stay apart from the ewes and young. The urial, or shapu, may have a long and great ruff below the throat in rams. It lives on the steep grassy hill slopes above the tree-line, scrub- covered hills, and the barren stony ranges of the cold, arid regions of the mountains of Afghanistan, Pakistan, Kashmir and north-western India. Its numbers decline drastically, due to competition with and the spread of diseases from domestic sheep and trophy hunting. The argali, or Marco Polo sheep, nayan or great Tibetan sheep, is the largest of the Indian sheep. Argali horns are massive, outwards curved, deeply wrinkled, and the heaviest and largest of all living sheep; in some varieties, they form more than one circle, following a corkscrew pattern (fi g. 395). A record length of 1.69 m has been noted.2 Argali are restricted on the subcontinent to north-eastern Afghanistan, Kashmir, the Tibetan Plateau, extreme northern India, Nepal and Sikkim. The argali is much less common than the urial. Blue sheep or bharal are only distantly related to sheep, and differ from them in diagnostic features. Their horns are comparatively smooth, without the transverse wrinkles seen in sheep. Blue sheep horns curve upward, then outward, and fi nally backward, from the sides of the head, resulting in a semicircular form, with the tips inclined inward (fi g. 396). Blue sheep are restricted to the Tibetan Plateau, the north- eastern part of Pakistan and the mountains of north-western Nepal, Sikkim and Bhutan. 2 G. Schaller, Mountain Monarchs (Chicago and London: University of Chicago Press, 1977)..