Monday, September 2, 2013

Gaur (ខ្ទីង)

The gaur (/ˈɡaʊər/Bos gaurus), also called Indian bison, is the largest extant bovine and is native to South Asia and Southeast Asia. The species is listed as vulnerable on the IUCN Red List since 1986, as the population decline in parts of the species' range is likely to be well over 70% during the last three generations. Population trends are stable in well-protected areas, and are rebuilding in a few areas which had been neglected.
The gaur is the tallest species of wild cattle. The Cambodian called Khting (ខ្ទីង). 

Gaur / Bos gaurus 
Conservation status
 Vulnerable (IUCN 3.1)


Characteristic 
The gaur is a strong and massively built species with a high convex ridge on the forehead between the horns, which bends forward, causing a deep hollow in the profile of the upper part of the head. There is a prominent ridge on the back. The ears are very large; the tail only just reaches the hocks, and in old bulls the hair becomes very thin on the back. In colour, the adult male gaur is dark brown, approaching black in very old individuals; the upper part of the head, from above the eyes to the nape of the neck, is, however, ashy grey, or occasionally dirty white; the muzzle is pale coloured, and the lower part of the legs are pure white or tan. The cows and young bulls are paler, and in some instances have a rufous tinge, which is most marked in groups inhabiting dry and open districts. The tail is shorter than in the typical oxen, reaching only to the hocks. They have a distinct ridge running from the shoulders to the middle of the back; the shoulders may be as much as 12 cm (4.7 in) higher than the rump. This ridge is caused by the great length of the spinous processes of the vertebrae of the fore-part of the trunk as compared with those of the loins. The hair is short, fine and glossy, and the hooves are narrow and pointed. The gaur has a head-and-body length of 250 to 330 cm (8.2 to 10.8 ft) with a 70 to 105 cm (28 to 41 in) long tail, and is 165 to 220 cm (5.41 to 7.2 ft) high at the shoulder. The average weight is 650 to 1,000 kg (1,400 to 2,200 lb), with an occasional large bull weighing up to 1,500 kg (3,300 lb). Males are about one-fourth larger and heavier than females.
Gaur do not have a distinct dewlap on the throat and chest. Both sexes carry horns, which grow from the sides of the head, curving upwards. Between the horns is a high convex ridge on the forehead. At their bases they present an elliptical cross-section, a characteristic that is more strongly marked in bulls than in cows. The horns are decidedly flattened at the base and regularly curved throughout their length, and are bent inward and slightly backward at their tips. The colour of the horns is some shade of pale green or yellow throughout the greater part of their length, but the tips are black. The horns, of medium size by large bovid standards, grow to a length of 60 to 115 cm (24 to 45 in).
The cow is considerably lighter in make and in colour than the bull. The horns are more slender and upright, with more inward curvature, and the frontal ridge is scarcely perceptible. In young animals the horns are smooth and polished. In old bulls they are rugged and dented at the base.
Gaur are among the largest living land animals. Only elephantsrhinos, the hippopotamus and the giraffe consistently grow heavier. Two species that naturally co-exist with the gaur are heavier: the Asian elephant and Indian rhinoceros.
Distribution and Habitat
Gaur is historically occurred throughout mainland South and Southeast Asia, including Vietnam, Cambodia, Laos, China, Thailand, Peninsular Malaysia, Myanmar, India, Bangladesh, Bhutan and Nepal. Today, the species is seriously fragmented within its range, ad regionally extinct in Sri Lanka.
In Cambodia, gaur declined considerably in the period from the late 1960s to the early 1990s. The most substantial population of the country remained in Mondulkiri Province, where up to 1000 individuals may have survived in a forested landscape of over 15,000 km2 (5,800 sq mi). Results of camera trapping carried out in 2009 suggested a globally significant population of gaur in the Mondulkiri Protected Forest and the contiguous Phnom Prich Wildlife Sanctuary
  1. Channa, P., Sovanna, P., Gray, T. N. E. (2010). Recent camera trap records of globally threatened species from the Eastern Plains Landscape, Mondulkiri. Cambodian Journal of Natural History 2010 (2): 89–93.
Ecology and behavior 
Where gaur have not been disturbed, they are basically diurnal. In other areas, they have become largely nocturnal due to forest molestation caused by people. In central India, they are most active at night, and are rarely seen in the open after 8 o'clock in the morning. During the dry season, herds congregate and remain in small areas, dispersing into the hills with the arrival of the monsoon. While gaur depend on water for drinking, they do not seem to bathe or wallow.
In January and February, gaur live in small herds of eight to 11 individuals, one of which is a bull. In April or May, more bulls may join the herd for mating, and individual bulls may move from herd to herd, each mating with many cows. In May or June, they leave the herd and may form herds of bulls only or live alone. Herds wander 2–5 km (1.2–3.1 mi) each day. Each herd has a nonexclusive home range, and sometimes herds may join in groups of 50 or more.[20] The average population density is about 0.6 animals per square kilometre (1.5 animals per square mile), with herds having home ranges of around 80 km2 (31 sq mi).
Gaur herds are led by an old adult female, the matriarch. Adult males may be solitary. During the peak of the breeding season, unattached males wander widely in search of receptive females. No serious fighting between males has been recorded, with size being the major factor in determining dominance. Males make a mating call of clear, resonant tones which may carry for more than 1.6 km (0.99 mi). Gaur have also been known to make a whistling snort as an alarm call, and a low, cow-like moo.
In some regions in India where human disturbance is minor, the gaur is very timid and shy. When alarmed, gaur crash into the jungle at a surprising speed. However, in Southeast Asia and South India, where they are used to the presence of humans, gaur are said by locals to be very bold and aggressive. They are frequently known to go into fields and graze alongside domestic cattle, sometimes killing them in fights. Gaur bulls may charge unprovoked, especially during summer, when the intense heat and parasitic insects make them more short-tempered than usual. To warn other members of its herd of approaching danger, the gaur lets out a high whistle for help.
Feeding 
Adina cordifolia (Haldina) tree leaves
Wild gaur graze and browse on a wider variety of plants than any other ungulate species of India, with a preference for the upper portions of plants, such as leaf blades, stems, seeds and flowers of grass species, including kadam.
During a survey in the Bhagwan Mahaveer Sanctuary and Mollem National Park, 32 species of plants were identified as food for gaur. They consume herbs, young shoots, flowers, fruits of elephant apple with a high preference for leaves. Food preference varies by season. In winter and monsoon, they feed on preferably fine and fresh grasses and herb species of the legume family, such as tick clover, but also browse on leaves of shrub species such as karvyIndian boxwoodmallow-leaved crossberryEast-Indian screw tree and chaste tree. In summer, they also feed on bark of teak, on fruit ofgolden shower tree, and on the bark and fruit of cashew. Gaur spent most of their daily time feeding. Peak feeding activity was observed between 6:30 and 8:30 am and between 5:30 and 6:45 pm. During the hottest hours of the day, 1:30 to 3:30 pm, they rest in the shade of big trees.
They may debark trees due to shortages of preferred food, and of minerals and trace elements needed for their nutrition, or for maintaining an optimum fiber/protein ratio for proper digestion of food and better assimilation of nutrients. They may turn to available browse species and fibrous teak bark in summer as green grass and herbaceous resources dry up. High concentrations of calcium (22400 ppm) and phosphorus (400 ppm) have been reported in teak bark, so consumption of teak bark may help animals to satisfy both mineral and other food needs. Long-term survival and conservation of these herbivores depend on the availability of preferred plant species for food. Hence, protection of the historically preferred habitats used by gaur is a significant factor in conservation biology.
Reproduction 
Gaur have one calf (or occasionally two) after a gestation period of about 275 days, about nine months, a few days less than domestic cattle. Calves are typically weaned after seven to 12 months. Sexual maturity occurs in the gaur's second or third year. Breeding takes place year-round, but typically peaks between December and June. The lifespan of a gaur in captivity is up to 30 years.
Natural Enemies
Due to their formidable size and power, gaur have few natural enemies. Leopards and dhole packs occasionally attack unguarded calves or unhealthy animals, but only the tiger and the saltwater crocodile have been reported to kill a full-grown adult. The habitat of gaurs and saltwater crocodiles seldom overlaps in recent times due to the decreasing range of both species. Tigers hunt young or infirm gaur, but have been reported to have also killed healthy bulls weighing at least 1,000 kg (2,200 lb).  When confronted by a tiger, the adult members of a gaur herd often form a circle surrounding the vulnerable young and calves, shielding them from the big cat. A herd of gaur in Malaysia encircled a calf killed by a tiger and prevented it from approaching the carcass.  InNagarahole National Park, upon sensing a stalking tiger, a herd of gaur walked as a menacing phalanx towards it, forcing the tiger to retreat and abandon the hunt. Gaur are not as aggressive toward humans as wild Asian water buffaloes.
There are several cases of tigers being killed by gaur. In one instance, a tiger was repeatedly gored and trampled to death by a gaur during a prolonged battle. A large male tiger carcass was found beside a small, broken tree in Nagarahole National Park, having been fatally struck against the tree by a large bull gaur a few days earlier. 
Treat 
In Laos, gaurs are highly threatened by poaching for trade to supply international markets, but also by opportunistic hunting, and specific hunting for home consumption. In the 1990s, they were particularly sought by Vietnamese poachers for their commercial value.
In Thailand, gaurs are highly threatened by poaching for commercial trade in meat and trophies.
Conservation 
Bos gaurus is listed in CITES Appendix I, and is legally protected in all range states.
  1.  Duckworth, J.W., Steinmetz, R., Timmins, R.J., Pattanavibool, A., Than Zaw, Do Tuoc, Hedges, S. (2008). "Bos gaurus"IUCN Red List of Threatened Species. Version 2012.2.International Union for Conservation of Nature.

More information: Click Here

No comments:

Post a Comment