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Ale, S., & Whelan, C. (2008). Reappraisal of the role of big, fierce predators.
Abstract: The suggestion in the early 20th century that top predators were a necessary component of ecosystems because they hold herbivore populations in check and promote biodiversity was at Wrst accepted and then largely rejected. With the advent of Evolutionary Ecology and a more full appreciation of direct and indirect effects of top predators, this role of top predators is again gaining acceptance. The previous views were predicated upon lethal effects of predators but largely overlooked their non-lethal effects. We suggest that
conceptual advances coupled with an increased use of experiments have convincingly demonstrated that prey experience costs that transcend the obvious cost of death. Prey species use adaptive behaviours to avoid predators, and these behaviours are not cost-free. With predation risk, prey species greatly restrict their use of available habitats and consumption of available food resources. Effects of top predators consequently cascade down to the trophic levels below them. Top predators, the biggies, are thus both the targets of and the means for conservation at the landscape scale. |
Ale S. (2005). Have snow leopards made a comeback to the Everest region of Nepal?.
Abstract: In the 1960s, the endangered snow leopard was locally extirpated from the Sagarmatha (Mt. Everest) region of Nepal. In this Sherpa-inhabited high Himalaya, the flourishing tourism since the ascent of Mt Everest in 1953, has caused both prosperity and adverse impacts, the concern that catalyzed the establishment of Mt. Everest National Park in the region in 1976. In the late 1980s, there were reports that some transient snow leopards may have visited the area from adjoining Tibet, but no biological surveys exist to confirm the status of the cats and their prey. Have snow leopards finally returned to the top of the world? Exploring this question was the main purpose of this research project. We systematically walked altogether 24 sign transects covering over 13 km in length in three valleys, i.e. Namche, Phortse and Gokyo, of the park, and counted several snow leopard signs. The results indicated that snow leopards have made a comeback in the park in response to decades of protective measures, the virtual cessation of hunting and the recovery of the Himalayan tahr which is snow leopard's prey. The average sign density (4.2 signs/km and 2.5 sign sites/km) was comparable to that reported from other parts of the cats' range in the Himalaya. On this basis, we estimated the cat density in the Everest region between 1 to 3 cats per 100 sq km, a figure that was supported by different sets of pugmarks and actual sightings of snow leopards in the 60 km2 sample survey area. In the study area, tahr population had a low reproductive rate (e.g. kids-to-females ratio, 0.1, in Namche). Since predators can influence the size and the structure of prey species populations through mortality and through non-lethal effects or predation risk, snow leopards could have been the cause of the population dynamics of tahr in Sagarmtha, but this study could not confirm this speculation for which further probing may be required.
Keywords: snow; snow leopards; snow leopard; snow-leopards; snow-leopard; leopards; leopard; region; Nepal; Report; International; international snow leopard trust; International-Snow-Leopard-Trust; trust; program; 1960; endangered; Sagarmatha; High; Himalaya; tourism; impact; establishment; national; national park; National-park; park; 1980; area; Tibet; surveys; survey; status; Cats; cat; prey; research; project; sign; transects; transect; length; valley; Response; hunting; recovery; Himalayan; tahr; density; densities; range; pugmarks; sighting; 60; study; population; predators; predator; structure; prey species; prey-species; species; populations; mortality; effects; predation; population dynamics
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Aizin B.M. (1969). Siberian ibex Capra sibirica Pall.
Abstract: It describes status of ibex in Kyrgyzstan, its distribution, behavioral patterns, enemies and competitors, etc. The enemies of ibex are snow leopard and wolf. All year round snow leopard preys on ibex its main food object and, therefore, should there be ibexes, snow leopards would be somewhere around. In winter, a considerable number of ibex dies from wolves. Sometimes dogs prey on ibex, too. Golden eagles and bearded vultures prey on young ibexes. However, poachers remain the most dangerous enemy.
Keywords: Kyrgyzsatn; Siberian ibex; distribution; life history; diet; predators; snow leopard.; 5890; Russian
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Poyarkov, A. D., & Subbotin, A. E. (2002). Strategic Priorities and the System of Measures for Snow Leopard Conservation in Russia.. Islt: Islt. |
Lydekker, R. (1907). The Game Animals of India, Burma, Malaya, and Tibet.. London: Rowland Ward. |
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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