The Nilgiri Tahr, (Nilgiritragus hylocrius Ropiquet and Hassanin, 2005) is an endangered caprid listed in Schedule I of the Wildlife (Protection) Act 1972 and categorized as ‘endangered’ by the IUCN. It is endemic to the hill ranges of the Western Ghats of Southern peninsular India in pockets where a suitable mosaic of Montane Grasslands and rugged terrain exist. Nilgiri Tahr is closely related to the Himalayan Tahr (Hemitragus jemlahicus C.H Smith, 1826) which occurs along the southern flanks of the Himalayas and the Arabian Tahr (Arabitragus jayakari Ropiquet and Hassanin, 2005), which inhibits the arid mountains of Sultanate of Oman.
An estimated 700-800 Nilgiri Tahr inhabit Eravikulam National Park, making it the largest wild population in the world. The Nilgiri Tahr generally inhabits the fringes of the grassy plateau and move on to the steep slabs and cliffs bordering it. They occasionally visit the Shrub Lands along the base of the cliffs. Tahr avoid Sholas, but sometime forage along their periphery. Nilgiri Tahr in Eravikulam National Park occurs in two types of groups; (The mixed groups and All male groups). The mixed group consists primarily of adult females and their sub adult off springs. Adult males join these groups during the rut and keep away at other times of the year. The male group consists of adult males of various classes. The maximum size of the mixed group is 150 animals and that of all male groups is 20 individuals. The usual number of young one produced is one although twins may occasionally occur. The rutting season occurs during monsoon (July and August) and the main birth season is January to mid February. Estimated gestation period is nearly 179 days. The predators of Nilgiri Tahr in Eravikulam National Park include Tiger, Leopard, Wild Dog and Jackal (C G Rice, 1984). However Easa (1995), through scat analyses, recorded only one incident of Tahr predation by leopard indicating almost nil predation by other animals.
Nilgiri Tahr commences feeding at the break of day and feed until late in the evening. They feed and rest intermittently; the rest intervals becoming longer as the day advances, until they become active again towards the evening. The Tahr was observed to feed primarily on 19 species of grasses, 12 species of shrubs along with a lichen and fresh shoots of dwarf bamboo. Chrysopogan zeylanicus form the major food species followed by Eulalia phaeothrix, Aruwdinella ciliat, Sehima nervosum and Ischaemum indicum iridicum ( Easa P.S, Sivaram M, KFRD research report No 242). Nights are spent on the cliffs or as close to them as possible. In undisturbed areas however, they often bed down in the open away from the cliffs.
The Male Nilgiri Tahr
A fully grown male Nilgiri Tahr, known as ‘Saddle Back’, stands about 100 cm at the shoulder and weighs about 100 Kg. The overall coloring is deep chocolate brown. This is particularly dark; almost black on the front of the fore and hind legs, the shoulder, the side of the abdomen, side of the face and the front of the muzzle. These contrast sharply with white facial stripe which drops from the forehead towards the corners of the mouth just anterior to the eyes, the white carpal patches on the front and outside of the forelegs and the silvery saddle. The side of the neck where it meets the shoulder is also sometimes lightened, as is the flank posterior to the saddle and an area around the eye. Long black hairs form a mane and mid dorsal stripe.
The horns (in both sexes) curve uniformally back and have no twist. The tips diverge slightly due to the plane of the horn being divergent from the body axis posteriorly and tilted slightly so as to converge dorsally. The inside surface is nearly flat and the back and outside are rounded. There is a distinct rib where the inside and front of the horns meet and the horn surface is covered with numerous fine crenulations amidst the slightly more evident annual rings. The horns of males are heavier and longer than those of the females reaching a maximum length of about 40 cm. The rutting season occurs during monsoon (July & August) and the main birth season was during January to mid February. Estimated gestation period is nearby 179 days (Rice 1984).
The Female Nilgiri Tahr
Female Nilgiri Tahr is shorter and slighter than their male counterparts. In contrast to the striking pelage of the male, the female is almost uniformly grey. The carpal patch is black against the light background. The facial markings are present but only faintly and the area around the eye and the cheek below it are brown. The mane and mid- dorsal stripe are much less conspicuous. The horns are slimmer and shorter, reaching a maximum length of about 26 cm.