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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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Wegge, P., Shrestha, R., Flagstad, O. (2012). Snow leopard Panthera uncia predation on livestock and wild prey in a mountain valley in northern Nepal: implications for conservation management. Wildlife Biology, 18(10.2981/11-049), 131–141.
Abstract: The globally endangered snow leopard Panthera uncia is sparsely distributed throughout the rugged mountains in Asia.
Its habit of preying on livestock poses a main challenge to management. In the remote Phu valley in northern Nepal, we obtained reliable information on livestock losses and estimated predator abundance and diet composition from DNA analysis and prey remains in scats. The annual diet consisted of 42%livestock. Among the wild prey, bharal (blue sheep/ naur) Pseudois nayaur was by far the most common species (92%). Two independent abundance estimates suggested that there were six snow leopards in the valley during the course of our study. On average, each snow leopard killed about one livestock individual and two bharal permonth. Predation loss of livestock estimated fromprey remains in scats was 3.9%, which was in concordance with village records (4.0%). From a total count of bharal, the only large natural prey in the area and occurring at a density of 8.4 animals/km2 or about half the density of livestock, snow leopards were estimated to harvest 15.1% of the population annually. This predation rate approaches the natural, inherent recruitment rate of this species; in Phu the proportion of kids was estimated at 18.4%. High livestock losses have created a hostile attitude against the snow leopard and mitigation measures are needed. Among innovative management schemes now being implemented throughout the species’ range, compensation and insurance programmes coupled with other incentive measures are encouraged, rather than measures to reduce the snow leopard’s access to livestock. In areas like the Phu valley, where the natural prey base consists mainly of one ungulate species that is already heavily preyed upon, the latter approach, if implemented, will lead to increased predation on this prey, which over time may suppress numbers of both prey and predator. |