Ovis hodgsoni Blyth 1841

201.

Tibetan Argali

Ovis hodgsoni

French: Mouflon du Tibet / German: Tibet-Wildschaf / Spanish: Argali del Tibet

Taxonomy. Ouvis hodgson: Blyth, 1841,

Tibet, probably on Nepal frontier.

This species is usually classified as a subspecies of O. ammon. Some authors assign two argali forms to the Tibetan Plateau: hodgsoni (southern Tibetan Plateau) and dalailamae (northern Tibetan Plateau). These two forms cannot be distinguished phenotypically or karyologically. Monotypic.

Distribution. N India (including N Sikkim), N Nepal, and SW China (mostly Xizang).

Descriptive notes. Head-body 167 cm (males) and 148 cm (females), tail 5-5 cm (males), shoulder height 115-118 cm (males) and 99-112 cm (females); weight 98— 105 kg (males) and 68 kg (a female older than four years). Basal horn circumference 39.4-43 cm (males) and 19 cm (females); horn length 86-145 cm (males) and 36-46 cm (females). Male skulls with horns weight 7.2-18 kg, longest recorded horn 145 cm (males). Horns of older males are broomed (broken off at ends). This species is characterized by a white ruff that surrounds the neck and is distinctly set off from the body. The body is grayish-brown near the back and paler on the sides, with a white rump patch that surrounds the tail. The front of all four legs is dark, but the back of the legs, belly, and face are white. A dark lateral stripe divides the upperparts from the white belly.

Habitat. Tibetan Argali occur on undulating or broken terrain, occasionally on upper slopes of mountains but not in rugged, precipitous areas. They are usually not found on plains or low hills, except when crossing from one mountain range to another. They use high ground such as broken,jagged cliff terrain to visually scan the landscape to detect predators and have adequate warning to outrun any threat. Their principal predator is the Gray Wolf (Canis lupus). Even when running from a predator, they usually do not seek cover in precipitous terrain. In Ladakh, 64% of Tibetan Argali observations were farther than 250 m from precipitous terrain, indicating their preference for areas with gentle, open slopes and away from cliffs. Snow cover is a major limiting factor in winter ranges. They require areas with minimal or patchy snow cover; areas with more than 20 cm of snow are avoided. Snow limits their ability to forage, and they are more vulnerable to predation in areas with deep snow. They occur in scattered, low-density populations with a discontinuous distribution.

Food and Feeding. They feed principally on graminoids and forbs in summer and shrubs in winter. In northern Nepal, Tibetan Argali diets in summer were dominated by forbs (85:4%), followed by graminoids (11%) and browse (3%). They also selected for forb communities and avoided shrub communities. In Xizang, they fed principally on forbs, followed by graminoids. During summer in northern India, males select sites with the highest percent of green forage followed by non-lactating and then lactating females.

Breeding. Mating occurs in December—January. Lambs are born after a gestation period of 155-165 days in late May and early June. Lactating females are more vigilant than non-lactating females and males.

Activity patterns. There is no specific information available for this species, but like other argali,it is probably active throughout the day, with feeding periods alternating with resting periods.

Movements, Home range and Social organization. Detailed studies have not been conducted. Although adult males and females form separate groups during non-mating periods, these two groups occupy the same habitats and segregation is spatio-temporal.

Status and Conservation. CITES Appendix I (as O. ammon hodgsoni). Classified as Near Threatened on The IUCN Red List (under O. ammon). Subsistence and commercial hunting has been a major mortality factor in the past, but a policy of firearms confiscation has resulted in reducing hunting by pastoralists. However, lack of enforcement of game laws and lack of personnel to patrol large areas are continuing problems. The long-term threat is displacement of Tibetan Argali populations from preferred grazing areas by domestic livestock. High domestic sheep densities result in unsustainable grazing practices; many former argali habitats are now dominated by livestock. Under these circumstances, Tibetan Argali are relegated to less productive foraging areas in higher, rugged terrain. Competition with livestock for winter ranges and associated human disturbance are factors limiting argali numbers. The small, isolated populations in highly fragmented landscapes make Tibetan Argali more vulnerable to extirpation. In a protected area in Ladakh during winter, they shifted to steeper habitats closer to cliffs and abandoned previously used plant communities with denser cover after the introduction of domestic sheep and goats. Argali also decreased foraging time by 20% when in the presence oflivestock. The disturbance caused by herders and their guard dogs is probably another factor in displacing argali. The Tibetan Argali population in Ladakh has remained at 300-360 animals despite a hunting ban since the 1980s; the failure of the population to increase is probably because of increased livestock and associated human disturbance. Only about 6500 occur in China.

Bibliography. Bunch et al. (2000), Ellerman & Morrison-Scott (1966), Fedosenko & Blank (2005), Fox, Nurbu & Chundawat (1991a), Geist (1991a), Groves & Grubb (2011), Grubb (2005), Harris (2007), Harris & Miller (1995), Harris & Reading (2008), Harris et al. (2005), Kapitanova et al. (2004), Mitchell & Punzo (1975), Namgail, Fox & Bhatnagar (2004, 2007, 2009), Schaller (1977, 1998), Shrestha et al. (2005), Singh, Bonenfant, Yoccoz & Coté (2010), Singh, Yoccoz et al. (2009), Valdez (1982), Wang Sung et al. (1997).