Head and body length: 110 cm (females), 150 cm (males)

Shoulder height: 80 cm (females), 110 cm (males)

Tail length: 10-15 cm

Adult weight: 50 kg (females), 80-100 kg (males)

A sexually dimorphic species, with males being significantly larger than females and with distinctive markings. Young individuals and adult females are an overall tawny gray with paler underparts; a dark stripe runs along the midline of the back. As males age (beginning around 2 years of age and continuing until full maturity at 6+ years), their coats darken to a deep blackish-brown. Simultaneously, several bright markings appear, including a silvery "saddle" over the back and white patches on the front legs. While the heads of adult females are the same color as their bodies, the faces of adult males darken to nearly black with a pair of silvery stripes running from the bases of the horns to the muzzle. Neither males nor females have a beard. Both sexes have fairly short, arcing horns with faint ridges on their forward surfaces. Those of males can reach up to 44.5 cm, while those of females tend to be shorter (typically up to 30 cm long) and less hefty.

Similar species

• The Himalayan tahr (Hemitragus jemlahicus) has a much shaggier coat; males in particular have a distinct ruff during the winter, and lack the contrasting markings of the Nilgiri tahr.

Gestation period: 178-190 days.

Litter size: One, rarely two.

Weaning: 4-6 months.

Sexual maturity: Females as early as 16 months. Males typically do not reach full social maturity until 6-8 years of age.

Life span: At least 9 years in the wild.

Nilgiri tahr breed year-round, although an increase in breeding behavior occurs between June and August during the monsoons. Infant tahr do not immediately follow their mothers, but are instead "tucked" in hiding spots while the mother leaves to forages for up to two months. Young may start to sample solid foods as early as two weeks.

Nilgiri tahr are typically active between dawn and dusk, being more active in the early morning and late afternoon. During midday, herds often retreat to the shaded shelter of cliff faces; these cliffs also serve as a refuge when tahr are threatened by predators. At least one member of the herd (usually an adult female) acts as a sentinel, sounding an alarm whistle or snort if danger is detected. Female herds typically remain within a particular home range, while adult males form looser associations and will move between female groups, occassionally joing all-male groups or remaining solitary. The striking markings of males aid in the development of dominance hierarchies, allowing rivals to assess their reltive status. Evenly-matched males fight for position by standing side by side and ramming each other, or by crashing together head-on.

Family group: Mixed and single-sex herds, typically with 11-71 individuals. Adult males may be solitary, especially during the hot season (March to May).

Diet: Grasses and herbs.

Main Predators: Leopard and dhole.

Nilgiri tahr are endemic to the Western Ghats mountain range of southern India. They are typically found in grassy meadow habitats near cliff faces (used for refuge from predators) at elevations of 1,200-2,600 m. Lower elevation forests are avoided. The approximate range is depicted in the map below.

IUCN Red List: Endangered (2008).

CITES Listing: Not listed (2017).

Threats: Habitat loss (conversion of land to agricultural fields, competition with livestock, and invasive plants) and poaching.

The estimated total population is only 1,800-2,000 animals, and is in decline. Nilgiri tahr inhabit several small, isolated pockets of habitat, which increases the risk of localized extinction and increases the risk of inbreeding by reducing gene flow. The current distribution of Nilgiri tahr is about one tenth of its historical range.