Throughout the Himalaya, mountain ungulates are threatened by hunting for meat and body parts, habitat loss, and competition with livestock. Accurate population estimates are important for conservation management but most of the available methods to estimate ungulate densities are difficult to implement in mountainous terrain. Here, we tested the efficacy of the recent extension of the point transect method, using camera traps for estimating density of two mountain ungulates: the group-living Himalayan blue sheep or bharal Pseudois nayaur and the solitary Himalayan musk deer Moschus leucogaster. We deployed camera traps in 2017–2018 for the bharal (summer: 21 locations; winter: 25) in the trans-Himalayan region (3,000–5,000 m) and in 2018–2019 for the musk deer (summer: 30 locations; winter: 28) in subalpine habitats (2,500–3,500 m) in the Upper Bhagirathi basin, Uttarakhand, India. Using distance sampling with camera traps, we estimated the bharal population to be 0.51 ± SE 0.1 individuals/km2 (CV = 0.31) in summer and 0.64 ± SE 0.2 individuals/km2 (CV = 0.37) in winter. For musk deer, the estimated density was 0.4 ± SE 0.1 individuals/km2 (CV = 0.34) in summer and 0.1 ± SE 0.05 individuals/km2 (CV = 0.48) in winter. The high variability in these estimates is probably a result of the topography of the landscape and the biology of the species. We discuss the potential application of distance sampling with camera traps to estimate the density of mountain ungulates in remote and rugged terrain, and the limitations of this method.

The snow leopard Panthera uncia is globally threatened and reliable information on its abundance, distribution and prey species is a prerequisite for its conservation. In October–November 2014 we assessed the distribution of the snow leopard in the recently established Api Nampa Conservation Area in the Nepal Himalayas. Within selected blocks we conducted sign surveys and counted the number of bharal Pseudois nayaur, its principal wild prey, along transects totalling 106 km. We recorded 203 putative snow leopard signs at an encounter rate of 1.91 signs/km. Generalized linear models of the number of signs detected per transect showed that elevation had a positive influence and human activities a negative influence on sign encounter rate; prey abundance had only a weak positive influence on sign encounter rate. Within the effectively surveyed area of c. 200 km2, we counted 527 bharal at an estimated density of 2.28 animals/km2. Recruitment of bharal was low, estimated at 48 kids/100 adult females, most likely a result of poor or overgrazed rangeland. We estimate the total number of bharal in this conservation area to be > 1,000, a prey base that could sustain 6–9 snow leopards. Based on our field observations, we identified human disturbance and habitat degradation associated with extraction of non-timber forest products, livestock grazing, and poaching as the main threats to the snow leopard. Standardized sign surveys, preferably supplemented by sampling with remote cameras or with genetic analysis of scats would provide robust baseline information on the abundance of snow leopards in this conservation area.

Excessive grazing by livestock is claimed to displace wild ungulates in the Trans-Himalaya. This study compares the seasonal diets and habitat use of sympatric wild naur Pseudois nayaur and domestic goat Capra hircus, sheep Ovis aries and free-ranging yak Bos grunniens in north Nepal and analyses their overlap both within and across seasons. Alpine meadow and the legumes Oxytropis and Chesneya were critical resources for all animal groups. High overlap occurred cross-seasonally when smallstock (sheep and goats) in summer used the spring and autumn ranges of naur. Relatively high total ungulate biomass (3028 kg km−2) and low recruitment of naur (56 young per 100 adult females in autumn) suggested interspecific competition. The spatio-temporal heterogeneity in composition and phenology of food plants across the steep gradient of altitude, together with rotational grazing, appears to indirectly facilitate coexistence of naur and smallstock. However, owing to high cross-seasonal (inter-seasonal) overlaps, competition is likely to occur between these two groups at high stocking densities. Within seasons, naur overlapped more with free-ranging yak than with smallstock. As their habitat use and diets were most similar in winter, when both fed extensively on the same species of shrubs, naur was most likely to compete with yak during that season.