Hemitragus hylocrius

Geographic Range

Nilgiri tahrs ( Hemitragus hylocrius ) were once abundant in grass-woodland mosaic habitat in rugged hills and mountain slopes of the southern Indian states of Kerala and Tamil Nadu. The endangered Nilgiri tahrs are endemic to the Western Ghats Mountains in south India. They are now limited to some 17 populations in the Nilgiri, Anamalai, Palani and Highwavy Hills, the Eravikulam area of the High Range, and possibly a few other mountains in the Western Ghats.

• Biogeographic Regions
• oriental oriental

Habitat

They prefer grass-woodland mosaic habitat in rugged hills, mountain slopes and plateaus at altitudes ranging from 1,200-2,200 m. Nilgiri tahr frequent the fringes of the grass-covered plateaus dominated by two main types of grass, Eulalia phaeotrix and Andropogon polyptichus .

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• scrub forest scrub forest
• mountains mountains

Physical Description

Nilgiri tahrs are goat-like animals with a short coat and short, laterally flattened and curved horns. Males are black with a silver saddle and bristly mane, while females are grayish brown with white bellies also having latterly-flattened curved horns. Measurements of these animals are as follows: head and body length 90-140 cm; height at the shoulder 61-106 cm; tail length 9-12 cm; weight 50-100 kg.

• Other Physical Features
• endothermic endothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger
• sexes colored or patterned differently
• ornamentation ornamentation

Reproduction

Nilgiri tahrs are polygynous, males compete for access to females through battles. Males will mate with as many females as they can gain access to.

• Mating System
• polygynous polygynous

Mating takes place throughout the year, but there is a birth peak in winter. Wild Nilgiri tahrs rarely give birth to twins. A single offspring is born after a gestation period of 180-242 days, and females can give birth twice in one year. Reproductive output varies greatly from year to year. Nilgiri tahrs breed well in captivity.

• Key Reproductive Features
• iteroparous iteroparous
• year-round breeding year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• viviparous viviparous

Females nurse and care for their offspring until they reach independence.

• Parental Investment
• altricial altricial
• female parental care female parental care
• post-independence association with parents

Lifespan/Longevity

Nilgiri tahrs have a relatively short life expectancy. Life expectancy at birth is estimated to be 3-3.5 years, though they may live longer.

Behavior

Nilgiri tahrs are active intermittently from dawn to dusk and are primarily grazers, living in herds ranging from 6 – 104 animals, with average group sizes of 9 for all-female groups and 27 for mixed herds. Males battle on mountain slopes in competition for mates.

• Key Behaviors
• terricolous
• diurnal diurnal
• crepuscular crepuscular
• motile motile
• nomadic nomadic
• territorial territorial
• social social
• dominance hierarchies dominance hierarchies

Communication and Perception

The primary modes of communication are visual, auditory and olfactory. Pheromones released in their urine communicate information about mate identification and reproductive activity, spacing mechanisms, and alarm.

• Communication Channels
• visual visual
• acoustic acoustic
• chemical chemical

• Other Communication Modes
• pheromones pheromones
• scent marks scent marks

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Preferred foods include various grasses and forbs. Species included among these various forage types are Eulalia phaeothrix , Andropogon polyptichus , Chrysopogon zelan , Eupatorium adenophoru , Strobilanthes kunthianus and Cymbopogon spp.

• Primary Diet
• herbivore herbivore
  • folivore folivore

• Plant Foods
• leaves

Predation

Anti-predator adaptions in Nilgiri tahrs include group defense and using horns for defense. Native predators of the Nilgiri tahr are the tiger ( Panthera tigris ), Indian wolves ( Canis lupus ) and dholes ( Cuon alpinus ). Another major predator are humans who poach these animals by means of shooting and snaring.

Ecosystem Roles

Nilgiri tahrs serve as a food source for predators such as tigers, wolves, and dholes. Their grazing maintains grass levels, which suppresses the probability of fire in grassland communities.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

Nilgiri tahrs are a valuable source of protein and income for local people. Unfortunately, poaching is the primary means of harvesting this animal. Therefore, this may be a positive economic importance for the local people but the continued poaching may eventually lead to the demise of the species.

• Positive Impacts
• food food
• body parts are source of valuable material
• ecotourism ecotourism

Economic Importance for Humans: Negative

These animals may compete for grazing with domestic livestock.

Conservation Status

Nilgiri tahrs have been protected by government law in India since 1972. These animals are likely candidates for reintroduction and also breed well in captivity. They are not only threatened by poaching, they are threatened by grazing, competition with domestic stock, hydroelectric projects, and habitat loss to agriculture and eucalyptus and wattle plantations. Ecological studies are needed to form a basis of management plans since sustainable harvesting and/or licensed sport hunting of a restored population could be a valuable source of protein and income for local people in a safe and legal mannerr.

In 1986 total numbers were estimated at 2,000 – 2,200, relatively unchanged since 1978. Available evidence suggests that the three largest populations have remained approximately stable in recent years. The largest known populations consist of nearly 550 animals each existing in the Eravikulam and Nilgiri Hills National Parks. These two populations comprise approximately 50% of the remaining animals. The remaining populations are of less than 100 animals.

Additional Links

Encyclopedia of Life

Contributors

Adam Herman (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor), University of Wisconsin-Stevens Point.

References

Davidar, E. 1978. Distribution and status of the Nilgiri tahr (*Hemitragus hylocrius*). Bombay Nat. Hist. Soc. , 75: 815-844.

Mishra, C., A. Johnsingh. 1998. Population and conservation status of the Nilgiri tahr *Hemitragus hylocrius* in Anamalai Hills, South India. Biological Conservation , 86: 199-206.

Nowak, R. 1991. Walker's Mammals of the World, 5th edn . Baltimore and London: University Press.

Rice, C. 1986. Conservation of Tahr. Caprinae News , 1: 7-9.

Rice, C. 1988. Habitat, Population Dynamics, and Conservation of the Nilgiri tahr, *Hemitragus hylocrius*. Biological Conservation , 44: 137-156.

Schaller, G. 1977. Mountain Monarchs . Chicago, USA: Univ. of Chicago Press.

World Conservation Monitoring Center. 2001. "Status accounts for selected threatened Indian mammals" (On-line ). Accessed 30 October 2002 at http://www.wcmc.org.uk/igcmc/rl_anml/indmams.html .