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Mishra, C., Van Wieren S., Ketner, P., Heitkonig, I., & Prins H. (2004). Competition between domestic livestock and wild bharal Pseudois nayaur in the Indian Trans-Himalaya. Journal of Animal Ecology, 73, 344–354.
Abstract: 1. The issue of competition between livestock and wild herbivores has remained contentious. We studied the diets and population structures of the mountain ungulate bharal Pseudois nayaur and seven species of livestock to evaluate whether or not they compete for forage. The study was conducted in the high altitude Spiti Valley, Indian Trans-Himalaya.
2. We compared resource (forage) availability and bharal population structures between rangelands differing in livestock density. Forage availability was estimated by clipping the standing graminoid biomass in sample plots. Livestock and bharal population structures were quantified through annual censuses. Seasonal diets of livestock were studied by direct observations, while those of bharal were quantified through feeding
signs on vegetation.
3. We found that livestock grazing causes a significant reduction in the standing crop of forage. Graminoid availability per unit livestock biomass was three times greater in a moderately grazed rangeland compared with an intensively grazed one.
4. There was considerable diet overlap among the herbivore species. In summer, bharal, yak Bos grunniens, horse Equus caballus, cow Bos indicus, and dzomo (yak-cow hybrids) fed predominantly on graminoids, while donkey E. asinus, sheep Ovis aries, and goat Capra hircus, consumed both graminoids and herbs. The summer diet of bharal was a subset of the diets of three livestock species. In winter, depleted graminoid availability caused bharal, yak and horse to consume relatively more herbs, while the remaining livestock species fed predominantly on graminoids. Diet overlap was less in winter but, in both seasons, all important forage species in the bharal diet were consumed
in substantial amounts by one or more species of livestock.
5. Comparison of the population structures of bharal between two rangelands differing in livestock density by
c. 30% yielded evidence of resource competition. In the intensively grazed rangeland, bharal density was 63% lower, and bharal population showed poorer performance (lower young : adult female ratios).
6.Synthesis and applications High diet overlap between livestock and bharal, together with density-dependent forage limitation, results in resource competition and a decline in bharal density. Under the present conditions of high livestock density and supplemental feeding, restricting livestock numbers and creating livestockfree areas are necessary measures for conserving Trans-Himalayan wild herbivores. Mediating competitive effects on bharal through supplemental feeding is not a feasible option.
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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.
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Oli, M. K., Taylor, I. R., & Rogers, M. K. (1993). Diet of the snow leopard (Panthera uncia) in the Annapurna Conservation Area, Nepal. Journal of Zoology London, 231(3), 365–370.
Abstract: The diet of the snow leopard (Panthera uncia) was studied from 213 scats collected between April 1990 and February 1991 in the Annapurna Conservation Area, Nepal. Seven species of wild and five species of domestic mammals were taken, as well as an unidentified mammal and birds. Blue sheep (Pseudois nayaur) were the most frequently eaten prey. Himalayan marmots (Marmota himalayana) were also important, except in winter when they were hibernating. During winter, snow leopards ate more Royle's pika (Ochotona roylei) and domestic livestock. Yaks were eaten more frequently than other livestock types.
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Oli, M. K. (1994). Snow leopards and blue sheep in Nepal: Densities and predator: prey ratio. Journal of Mammalogy, 75(4), 998–1004.
Abstract: I studied snow leopards (Panthera uncia) and blue sheep (Pseudois nayaur) in Manang District, Annapurna Conservation Area, Nepal, to estimate numbers and analyze predator-prey interactions. Five to seven adult leopards used the 10-5-km-2 study area, a density of 4.8 to 6.7 leopards/100 km-2. Density of blue sheep was 6.6 10.2 sheep/km-2, and biomass density was 304 kg/km-2. Estimated relative biomass consumed by snow leopards suggested that blue sheep were the most important prey; marmots (Marmota himalayana) also contributed significantly to the diel 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 1:114-1:159 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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Oli, M. K., & Rogers, E. M. (1996). Seasonal pattern in group size and population composition of blue sheep in Manang, Nepal. Journal of Wildlife Management, 60(4), 797–801.
Abstract: Blue sheep (Pseudois nayaur) are the principal prey of the endangered snow leopard (Panthera uncia) in the Himalayas and adjacent ranges. We studied group size and population composition of blue sheep in Manang District, Annapurna Conservation Area, Nepal. Overall mean group size was 15.6 (SE = 1.3), but it varied seasonally (P lt 0.001), with significantly smaller groups in winter than in other seasons. Mixed groups were most numerous in all seasons, and there was no evidence of sexual segregation. Yearling sex ratio (93.7 M:100 F) did not vary seasonally, nor did the ratio deviate from parity. Adult sex ratio showed a seasonal pattern favoring males post-parturition but female-biased during the rut and pre-parturition. Seasonal variation in sex-specific mortality is offered as a plausible explanation for the observed pattern in adult sex ratio.
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Oli, M. K. (1996). Seasonal patterns in habitat use of blue sheep Pseudois nayaur (Artiodactyla, Bovidae) in Nepal. Mammalia, 60(2), 187–193.
Abstract: Blue sheep (Pseudois nayaur) are the main prey of the endangered snow leopard (Panthera uncia) as well as an important game species in Nepal. A knowledge of how blue sheep utilize their habitat is essential for the scientific management of the sheep and for the conservation of the snow leopard, but we only have a limited understanding of this aspect of blue sheep ecology. I studied the habitat use pattern of blue sheep by direct observation in the Anna-purna Conservation Area, Nepal where they occur sympatrically with the snow leopard. The sheep used grassland habitats more frequently during pre-parturition (spring) and post-parturition (autumn) than other habitat types, but scrub and grassland habitats were used equally frequently during the rut (winter). The sheep used smooth undulating slopes of medium steepness (<40 degrees) on southerly aspects within the elevation range of 4,200-4,600 m most frequently in all seasons, and there was no evidence of seasonal migration along the elevation gradient. When not in broken landforms (e.g., cliff, landslides), the sheep maintained proximity (less than or equal to 150 m) to such features suggesting their importance as escape cover (i.e., from predators). The use of habitat components by blue sheep appeared to be related to the distribution of foraging areas and escape cover.
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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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Schaller, G. (1988). Survey of Mountain Wildlife in Xinjiang, Report # 7.
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Wikramanayake, E. Tracking snow leopard and blue sheep, WWF conservationist Eric Wikramanayake goes on a wildlife survey in Bhutan.
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Schaller, G. (1988). Wildlife Survey in Tibet, Report #8.
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