Himalayan Serow in Bhutan

The Himalayan serow (Capricornis thar) is a goat-antelope of the subfamily Caprinae, found along the southern flanks of the Himalaya from northeastern Pakistan through northern India, Nepal, Bhutan and into northern Myanmar and southern China. Older taxonomy treated the Himalayan animal as a full species, Capricornis thar; the IUCN's 2020 assessment instead treats it as a subspecies of the mainland serow, Capricornis sumatraensis ssp. thar, and lists the parent species as Vulnerable. Both names are in active use in the recent literature.^[1][2]

In Bhutan the serow is widespread but cryptic, occurring in steep, densely forested slopes from the southern foothills at around 200 metres up to about 3,000 metres in the temperate broadleaf and conifer belts. It is recorded from most of the country's national parks, including Royal Manas National Park, Jigme Singye Wangchuck National Park, Jigme Dorji National Park, Wangchuck Centennial National Park and Phrumshengla National Park. It forms part of the prey base for the snow leopard at higher elevations and for the common leopard and the Bengal tiger at lower ones.^[3][4]

This article covers the animal's identification, distribution and habitat in Bhutan, behaviour, threats, conservation status and ecological role.

Identification

The Himalayan serow is a stocky, donkey-sized ungulate, dark in colouration with a coarse black to dark-brown coat, paler underparts, a short black mane along the neck and shoulders, and short curved black horns in both sexes. The legs are long relative to the body and are often paler in colour. Adults stand around 90 to 100 centimetres at the shoulder. The animal's heavy build and short horns distinguish it readily from the smaller, more slender goral (Naemorhedus goral), which shares much of its range.^[2][5]

Distribution and habitat in Bhutan

Records from camera-trapping work conducted by the Department of Forests and Park Services, including the surveys associated with the national tiger census and the Wangchuck Centennial Park snow-leopard survey, document the species across a wide elevational band. The same surveys note that the animal is rarely observed directly because of its preference for dense scrub and broken terrain. The species occupies subtropical broadleaf forest in the south, mid-altitude broadleaf and oak forest in the central belt, and conifer-rhododendron forest up to the upper treeline.^[3][6]

Behaviour and ecology

The serow is solitary outside the rut and territorial, with adults occupying small home ranges centred on a network of latrines and rubbing posts. It feeds on a mixed diet of grasses, herbs, leaves, shoots and seasonal fruit. Birth of single young (occasionally twins) occurs after a gestation of around eight months, typically in late spring. The animal is a strong climber and uses cliff faces and rock outcrops as both refuges from predators and as sleeping sites.^[2][5]

Threats

The principal threats documented across the range and in Bhutan are habitat fragmentation through road construction, hydropower infrastructure and the clearance of forest for cardamom and other agroforestry, together with poaching for bushmeat and for body parts used in traditional medicine. Among the more specific pressures is the trade in serow gallstones (bezoars) and bones, which appear in regional traditional-medicine markets across the eastern Himalaya. Within Bhutan's protected areas direct hunting is reported as low, but accidental capture in snares set for other species is a documented mortality cause.^[1][7]

Conservation status and legal protection

The IUCN's 2020 assessment of Capricornis sumatraensis (which subsumes the Himalayan animal) lists the species as Vulnerable, on the basis of an inferred decline of more than 30 per cent over three generations. Within Bhutan the serow is listed in Schedule I (totally protected) under the Forest and Nature Conservation Rules and Regulations, prohibiting hunting, capture and trade except under specific scientific or management permits.^[1][8]

Ecological role

Camera-trap and prey-base studies in Bhutan, including those led by Tshering Tempa and colleagues, identify the serow as a moderate-density component of the ungulate community. It is reported as occasional prey for snow leopards in the alpine zone and for common leopards and tigers in the temperate and subtropical belts, although in most prey-base reconstructions barking deer, sambar and wild boar feature more prominently. The animal's preference for steep, rocky terrain reduces its accessibility to large felids relative to other ungulates of similar size.^[3][6]