Abstract: We used logistic regression to examine factors that affected the spatial distribution of sign (scrapes, feces, footprints, spray or scent marks, and rubbing sites) in a newly reestablished population of snow leopards (Uncia uncia) in Sagarmatha (Mount Everest) National Park, Nepal. Our results indicate that terrain and human activity were the most important factors determining the spatial distribution of leopard activity, whereas presence of their major prey species (Himalayan tahr [Hemitragus jemlahicus]) had only a moderate effect. This suggests that localities at which these animals are active represent a trade-off between suitable habitat and avoidance of potential risk from anthropogenic origins. However, the influence of prey presence was likely underestimated because of the methodology used, and likely weighed in the trade-off as well.

Abstract: Decline of wild prey populations in the Himalayan region, largely due to competition with livestock, has been identified as one of the main threats to the snow leopard Uncia uncia. Studies show that bharal Pseudois nayaur diet is dominated by graminoids during summer, but the proportion of graminoids declines in winter. We explore the causes for the decline of graminoids from bharal winter diet and resulting implications for bharal conservation. We test the predictions generated by two alternative hypotheses, (H1) low graminoid availability caused by livestock grazing during winter causes bharal to include browse in their diet, and, (H2) bharal include browse, with relatively higher nutrition, to compensate for the poor quality of graminoids during winter. Graminoid availability was highest in areas without livestock grazing, followed by areas with moderate and intense livestock grazing. Graminoid quality in winter was relatively lower than that of browse, but the difference was not statistically significant. Bharal diet was dominated by graminoids in areas with highest graminoid availability. Graminoid contribution to bharal diet declined monotonically with a decline in graminoid availability. Bharal young to female ratio was three times higher in areas with high graminoid availability than areas with low graminoid availability. No starvation-related adult mortalities were observed in any of the areas. Composition of bharal winter diet was governed predominantly by the availability of graminoids in the rangelands. Since livestock grazing reduces graminoid availability, creation of livestock free areas is necessary for conservation of grazing species such as the bharal and its predators such as the endangered snow leopard in the Trans-Himalaya.

Abstract: The loss of mammalian herbivores from grazing ecosystems has become a major concern,and efforts to stem such losses are stymied by lack of information on the proximate and ultimate factors influencing their distributions and diversity patterns. This research investigated the distribution, species-richness patterns and underlying mechanisms in mammalian herbivores of the Trans-Himalayan region of Ladakh, India. It adopted a multi-spatial approach to understand these issues in the little-known herbivore assemblage of the region. Since vegetation is the most important factor that determines the distribution of herbivores, first I researched the distribution and abundance patterns of vascular plants along an altitudinal gradient at different spatial scales. Both plant species-richness and aboveground biomass showed a hump-shaped relationship with altitude. Such a relationship in case of species-richness is expected, but it is contrary to my expectation of a negative linear relationship, in case of abundance. I relate this unexpected pattern to the limited precipitation and pervasive livestock grazing at lower altitudes in this dry alpine environment. I then investigated the biogeography of mammalian herbivores, and found that they form geographical groups on the basis of their evolutionary histories. Subsequently, I assessed the niche relationship between Asiatic ibex Capra ibex siberica and blue sheep Pseudois nayaur, the most common large herbivores in Ladakh, to see whether local level processes like competition generate spatial pattern of herbivore species-richness. The results showed that blue sheep constrains the distribution of ibex, which implies that competition amongst native species does play a role in structuring large herbivore assemblages in the region. Recognising the lack of information on large herbivores’ niche variation across assemblages, I also studied blue sheep’s niche width in relation to herbivore speciesrichness. It became apparent that the species’ niche varies across assemblages with different number of sympatric species, which could negatively influence the animal’s reproductive performance and population. Finally, I asked if the distributional range of the endangered Ladakh urial Ovis vignei vignei is constrained by the abundant blue sheep, and found that these two species associate randomly at large geographical scales, but cooccur at the landscape level as a result of local habitat-level resource partitioning. These results contribute towards understanding the mechanisms responsible for the formation and maintenance of large herbivore assemblages in the Trans-Himalaya and other mountainous regions of the world.

Abstract: Twenty-five years ago, the snow leopard Uncia uncia, an endangered large cat, was eliminated from what is now Sagarmatha National Park (SNP). Heavy hunting pressure depleted that area of most medium-large mammals, before it became a park. After three decades of protection, the cessation of hunting and the recovery of wild ungulate populations, snow leopards have recently returned (four individuals). We have documented the effects of the return of the snow leopard on the population of its main wild prey, the Himalayan tahr Hemitragus jemlahicus, a 'near-threatened' caprin. Signs of snow leopard presence were recorded and scats were collected along a fixed trail (130 km) to assess the presence and food habits of the snow leopard in the Park, from 2004 to 2006. Himalayan tahr, the staple of the diet, had a relative occurrence of 48% in summer and 37% in autumn, compared with the next most frequent prey, musk deer Moschus chrysogaster (summer: 20%; autumn: 15%) and cattle (summer: 15%; autumn: 27%). In early summer, the birth rate of tahr (young-to-female ratio: 0.8-0.9) was high. The decrease of this ratio to 0.1-0.2 in autumn implied that summer predation concentrated on young tahr, eventually altering the population by removing the kid cohort. Small populations of wild Caprinae, for example the Himalayan tahr population in SNP, are sensitive to stochastic predation events and may be led to almost local extinction. If predation on livestock keeps growing, together with the decrease of Himalayan tahr, retaliatory killing of snow leopards by local people may be expected, and the snow leopard could again be at risk of local extinction. Restoration of biodiversity through the return of a large predator has to be monitored carefully, especially in areas affected by humans, where the lack of important environmental components, for example key prey species, may make the return of a predator a challenging event.