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Namgail, T., Fox, J., & Bhatnagar, Y. V. (2004). Habitat segregation between sympatric Tibetan argali Ovis ammon hodgsoni and blue sheep Pseudois nayaur in the Indian Trans-Himalaya. Journal of Zoology, 262, 57–63.
Abstract: Tibetan argali Ovis ammon hodgsoni and blue sheep Pseudois nayaur have almost completely overlapping distributions encompassing most of the Tibetan plateau and its margins. Such a sympatric distribution of related species with similar ecological requirements implies that there is some degree of resource partitioning. This may be accomplished on the basis of habitat and/or diet separation. This study evaluated such ecological separation on the basis of physical habitat partitioning by these two sympatric ungulates in Hemis High Altitude National Park, Ladakh, India, in an area where the argali established a small new population in 1978. Such separation was tested for
on the basis of expected difference between the species in their proximity to cliffs, associated with species-specific anti-predator behaviour. Tibetan argali selected habitats away from cliffs while blue sheep selected habitats close to cliffs. Blue sheep also selected steep slopes whereas argali selected gentle slopes. The two species did not differ in their use of habitats in terms of elevation. They did, however, differ in their use of plant communities; blue sheep selected sub-shrub and grass-dominated communities whilst argali selected forb-dominated communities. We suggest that the two species coexist in this site as a result of the differential use of habitat associated with their species-specific anti-predator strategies. |
Oli, M. (1994). Snow leopards and blue sheep in Nepal: Densities and predator: Prey ratio (Vol. 75).
Abstract: I studied snow leopards (Panthera uncia) and blue sheep (Pseudois nayaur) in Manang District, Annapurna Conservation Area, Nepal, to estimate numbers and analyze predatorprey interactions. Five to seven adult leopards used the 105-km2 study area, a density of 4.8 to 6.7 leopards/100 km2. Density of blue sheep was 6.6-10.2 sheep/km2, and biomass density was 304 kg/km2. Estimated relative biomass consumed by snow leopards suggested that blue sheep were the most important prey; marmots (Marmota himalayana) also contributed significantly to the diet of snow leopards. Snow leopards in Manang were estimated to harvest 9-20% of total biomass and 11-24% of total number of blue sheep annually. Snow leopard :blue sheep ratio was 1 :1 14-1 :159 on a weight basis, which was considered sustainable given the importance of small mammals in the leopard's diet and the absence of other competing predators.
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Schaller, G. B. (1987). Status of large mammals in the Taxkorgan Reserve, Xinjiang, China. Biological-Conservation, 42(1), 53–71.
Abstract: A status survey of large mammals was conducted in the W half of 14 000 km“SUP 2” Taxkorgan Reserve. Only one viable population of fewer than 150 Marco Polo sheep Ovis ammon poli survives; it appears to be augmented by adult males from Russia and Afghanistan during the winter rut. Asiatic ibex Capra ibex occur primarily in the western part of the reserve and blue sheep Pseudois nayaur – the most abundant wild ungulate – in the E and SE parts. The 2 species overlap in the area of contact. Counts revealed an average wild ungulate density of 0.34 animals km“SUP -2”. Snow leopard Panthera uncia were rare, with possibly 50-75 in the reserve, as were wolves Canis lupus and brown bear Ursus arctos. The principal spring food of snow leopard was blue sheep (60%) and marmot (29%). Local people have greatly decimated wildlife. Overgrazing by livestock and overuse of shrubs for fuelwood is turning this arid steppe habitat into desert. -from Authors
Keywords: Marco-Polo; sheep; Ovis-ammon-poli; Asiatic; ibex; Capra-ibex; blue-sheep; Pseudois-nayaur; snow; leopard; Panthera-uncia; wolf; Canis-lupus; brown; bear; Ursus-arctos; marmot; survey; status; China; Taxkorgan; reserve; capra ibex; snow leopard; blue; browse; marco polo; ovis; ammon; poli; capra; pseudois nayaur; panthera; uncia; canis; lupus; ursus arctos; 880
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Sharma, R. K., Sharma, K., Borchers, D., Bhatnagar, Y. V., Suryawanshi, K. S., Mishra, C. (2020). Spatial variation in population-density, movement and detectability of snow leopards in
2 a multiple use landscape in Spiti Valley, Trans-Himalaya. bioRxiv, .
Abstract: The endangered snow leopard Panthera uncia occurs in human use landscapes in the mountains of South and Central Asia. Conservationists generally agree that snow leopards must be conserved through a land-sharing approach, rather than land-sparing in the form of strictly protected areas. Effective conservation through land-sharing requires a good understanding of how snow leopards respond to human use of the landscape. Snow leopard density is expected to show spatial variation within a landscape because of variation in the intensity of human use and the quality of habitat. However, snow leopards have been difficult to enumerate and monitor. Variation in the density of snow leopards remains undocumented, and the impact of human use on their populations is poorly understood. We examined spatial variation in snow leopard density in Spiti Valley, an important snow leopard landscape in India, via spatially explicit capture recapture analysis of camera trap data. We camera trapped an area encompassing a minimum convex polygon of 953 km . We estimated an overall density of 0.49 (95% CI: 0.39-0.73) adult snow leopards per 100 km . Using AIC, our best model showed the density of snow leopards to depend on wild prey density, movement about activity centres to depend on altitude, and the expected number of encounters at the activity centre to depend on topography. Models that also used livestock biomass as a density covariate ranked second, but the effect of livestock was weak. Our results highlight the importance of maintaining high density pockets of wild prey populations in multiple use landscapes to enhance snow leopard conservation.
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Shrestha, R., & Wegge, P. (2008). Habitat relationships between wild and domestic herbivores in Nepalese trans – Himalaya. Journal of Arid Environments, 72, 914–925.
Abstract: In the semi-arid ecosystems of Asia, where pastoralism is a main subsistence occupation, grazing competition from domestic stock is believed to displace the wild ungulates. We studied the habitat relationships among sympatric naur and domestic yak and smallstock in Phu valley in upper Manang district, Nepal, on the basis of their distribution on vegetation types, elevation and slope. To control for the disturbance effect by humans, we collected the data on naur from those ranges where domestic stock were not being attended by herders. We applied correspondence analysis to explore habitat associations among animal groups (n ¬ 1415) within and across-seasons. Within each association, interspecific habitat overlaps and species habitat preferences were calculated. Naur was strongly associated with free-ranging yak as they used similar altitudinal ranges in all seasons, except in spring. Their distributions on vegetation types and slopes were also quite similar, except for a stronger preference for alpine meadows by naur during summer and winter. Naur and smallstock did not form temporal associations as the latter consistently used lower elevations. In autumn and spring, however, naur spatially overlapped with the summer range of smallstock, and both preferred the alpine meadow habitat during these periods. Alpine meadow was the least abundant vegetation type but was consistently and preferentially used by all animal groups across seasons. At high stocking densities, all three animals groups are therefore likely to compete for this vegetation type. The role of spatio-temporal heterogeneity for interpreting the interspecific relationships among ungulates in the semi-arid rangelands of the trans-Himalaya is discussed.
Keywords: blue sheep; Competition; domestic; habitat partitioning; naur; Nepal; pastoralism; pseudois nayaur; trans-himalaya
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Shrestha, R., & Wegge, P. (2008). Wild sheep and livestock in Nepal Trans-Himalaya: coexistence or competition? Environmental Conservation, 32(2), 125–136.
Abstract: 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. Alpinemeadow 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 crossseasonal (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.
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Shrestha, R., Wegge, P., & Koirala, R. A. (2005). Summer diets of wild and domestic ungulates in Nepal Himalaya. Journal of Zoology, 266, 111–119.
Abstract: The selection of summer forage by three sympatric ungulates in the Damodar Kunda region of upper Mustang in
north Nepal was studied to assess the extent of food overlap between them. To compare their diets, a microhistological technique of faecal analysis was used, adjusted for inherent biases by comparing it with bite-count data obtained in domestic goats. Tibetan argali Ovis ammon hodgsoni, naur (blue sheep or bharal) Pseudois nayaur and domestic goat Capra hircus consumed mostly forbs, graminoids and browse, respectively. The proportions of food items in their diets were significantly different both at the plant species (P<0.02) and at the forage category level (P<0.001). Except for sharing three common plants (Agrostis sp., Stipa sp. and Potentilla fruticosa), dietary overlap at the species level was quite low. At the forage category level, naur and domestic goat overlapped more than the other ungulate pairs. Although all three species were opportunistic, mixed feeders, argali was a more selective forb specialist grazer than the other two ungulates. Owing to some spatial separation and little dietary overlap, interspecific competition for summer forage was low. If animal densities increase, however, goats are expected to compete more with naur than with argali because of their more similar diets. Owing to differences in forage selection by argali and naur throughout their large geographical ranges, reflecting adaptations to local ecological conditions, inferences regarding forage competition between domestic livestock and these two wild caprins need to be made from local, site-specific studies, rather than from general diet comparisons. |
Suryawanshi, K., K. (2011). Sunshine and the Shadow. Hornbill, (April-June), 34–37.
Abstract: Kulbhushansingh Suryawanshi shares an update on his blog which describes snow leopard sightings in Spiti, Himachal Pradesh, while studying the foraging behavior and eating habits of blue sheep (Pseudois nayaur).
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Suryawanshi, K. R. (2009). Towards snow leopard prey recovery: understanding the resource use strategies and demographic responses of bharal Pseudois nayaur to livestock grazing and removal; Final project report.
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.
Keywords: project; snow; snow leopard; snow-leopard; leopard; network; conservation; program; prey; recovery; resource; use; strategy; demographic; Response; bharal; Pseudois; pseudois nayaur; Pseudois-nayaur; nayaur; livestock; grazing; Report; decline; wild; populations; population; Himalayan; region; Competition; threats; threat; uncia; Uncia uncia; Uncia-uncia; study; diet; winter; Test; browse; nutrition; areas; area; young; Female; times; High; Adult; mortality; species; predators; predator; endangered; trans-himalaya; transhimalaya
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Suryawanshi, K. R., Bhatnagar, Y., & Mishra, C. (2009). Why should a grazer browse? Livestock impact on winter resource use by bharal Pseudois nayaur
. Oecologia, , 1–10.
Abstract: Many mammalian herbivores show a temporal diet variation between graminoid-dominated and browse dominated diets. We determined the causes of such a diet shift and its implications for conservation of a medium sized ungulate-the bharal Pseudois nayaur. Past studies show that the bharal diet is dominated by graminoids (>80%) during summer, but the contribution of graminoids declines to about 50% in winter. We tested the predictions generated by two alternative hypotheses explaining the decline: low graminoid availability during winter causes bharal to include browse in their diet; bharal include browse, with relatively higher nutritional quality, in their diet to compensate for the poor quality of graminoids during winter. We measured winter graminoid availability in areas with no livestock grazing, areas with relatively moderate livestock grazing, and those with intense livestock grazing pressures. The chemical composition of plants contributing to the bharal diet was analysed. The bharal diet was quantiWed through signs of feeding on vegetation at feeding locations. Population structures of bharal populations were recorded using a total count method. Graminoid availability was highest in areas without livestock grazing, followed by areas with moderate and intense livestock grazing. The bharal diet was dominated by graminoids (73%) in areas with highest graminoid availability. Graminoid contribution to the bharal diet declined monotonically (50, 36%) with a decline in graminoid availability. Bharal young to female ratio was 3 times higher in areas with high graminoid availability than areas with low graminoid availability. The composition of the bharal winter diet was governed predominantly by the availability of graminoids in the rangelands. Our results suggest that bharal include more browse in their diet during winter due to competition from livestock for graminoids. Since livestock grazing reduces graminoid availability, creation of livestock-free areas is necessary for the conservation of grazing species such as the bharal and its predators including the endangered snow leopard in the Trans-Himalaya.
Keywords: browse; livestock; impact; winter; resource; use; bharal; Pseudois; pseudois nayaur; Pseudois-nayaur; nayaur; diet; variation; diets; conservation; Media; study; decline; areas; area; grazing; Pressure; plants; plant; sign; feeding; location; population; structure; populations; using; young; Female; times; High; Competition; species; predators; predator; endangered; snow; snow leopard; snow-leopard; leopard; trans-himalaya; transhimalaya
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