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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. |
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Ale, S., & Brown, J. (2007). The contingencies of group size and vigilance (Vol. 9).
Abstract: Background: Predation risk declines non-linearly with one's own vigilance and the vigilance of others in the group (the 'many-eyes' effect). Furthermore, as group size increases, the individual's risk of predation may decline through dilution with more potential victims, but may increase if larger groups attract more predators. These are known, respectively, as the dilution effect and the attraction effect.
Assumptions: Feeding animals use vigilance to trade-off food and safety. Net feeding rate declines linearly with vigilance. Question: How do the many-eyes, dilution, and attraction effects interact to influence the relationship between group size and vigilance behaviour? Mathematical methods: We use game theory and the fitness-generating function to determine the ESS level of vigilance of an individual within a group. Predictions: Vigilance decreases with group size as a consequence of the many-eyes and dilution effects but increases with group size as a consequence of the attraction effect, when they act independent of each other. Their synergetic effects on vigilance depend upon the relative strengths of each and their interactions. Regardless, the influence of other factors on vigilance – such as encounter rate with predators, predator lethality, marginal value of energy, and value of vigilance – decline with group size. Keywords: attraction effect,contingency,dilution effect,fitness,group-size effect,many-eyes effect,predation risk,vigilance behaviour; predation; decline; potential; predators; predator; feeding; Animals; Animal; use; food; effects; Relationship; behaviour; methods; game; Interactions; interaction; factor; value; Energy
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Ale, S. B., Yonzon, P., & Thapa, K. (2007). Recovery of snow leopard Uncia uncia in Sagarmatha (Mount Everest) National Park, Nepal (Vol. 41).
Abstract: From September to November 2004 we conducted surveys of snow leopard Uncia uncia signs in three major valleys in Sagarmatha (Mount Everest) National Park in Nepal using the Snow Leopard Information Management System, a standardized survey technique for snow leopard research. We walked 24 transects covering c. 14 km and located 33 sites with 56 snow leopard signs, and 17 signs incidentally in other areas. Snow leopards appear to have re-inhabited the Park, following their disappearance c. 40 years ago, apparently following the recovery of Himalayan tahr Hemitragus jemlahicus and musk deer Moschus chrysogaster populations. Taken together the locations of all 73 recent snow leopard signs indicate that the species is using predominantly grazing land and shrubland/ open forest at elevations of 3,000-5,000 m, habitat types that are also used by domestic and wild ungulates. Sagarmatha is the homeland of c. 3,500 Buddhist Sherpas with .3,000 livestock. Along with tourism and associated developments in Sagarmatha, traditional land use practices could be used to ensure coexistence of livestock and wildlife, including the recovering snow leopards, and ensure the wellbeing of the Sherpas.
Keywords: Nepal; recovery; Sagarmatha Mount Everest National Park; snow leopard; Uncia uncia; surveys; survey; snow; snow-leopard; leopard; uncia; Uncia-uncia; valley; Sagarmatha; national; national park; National-park; park; using; information; management; system; research; transects; transect; sign; areas; area; snow leopards; snow-leopards; leopards; 40; Himalayan; tahr; musk; musk-deer; deer; location; recent; species; grazing; land; Forest; habitat; domestic; wild; ungulates; ungulate; livestock; tourism; development; traditional; land use; land-use; use; wildlife
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Ale, S. B. (1998). Religion and Snow Leopards in Nepal (Vol. xvi). Seattle: Islt.
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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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Ahmad, A. (1993). Environmental impact assessment in the Himalayas: An ecosystem approach (Vol. 22).
Abstract: The impact of human activities on the Himalayan bio-geophysical, socioeconomic and cultural environments has been analyzed. The main man-induced activities which threaten the equilibrium of Himalayan Mountain ecosystems are unplanned land use, cultivation on steep slopes, overgrazing, major engineering activities, overexploitation of village or community forests, shifting cultivation, unplanned tourism and urbanization. Cold desert conditions prevail in 41 692 square kilometers of the northwestern Himalayas. The geomorphological conditions and arrested succession, checking the climax formation, are major causes of landslides. Sedimentation, changes in surface and groundwater hydrology and clearfelling of broadleaved plant species have caused eutrophication, drying up of natural springs and receding of glaciers. Wild fauna like Musk deer (Moschus mischiferus) and Snow Leopard (Panthera uncial) are now under threat due to changes in their habitats. Population pressure, migration and settlements are major causes of poverty and agglomeration. And jeopardize the Himalayan environment. Based on detailed environmental impact assessment, an ecosystem approach has been proposed for resources conservation and environmentally sustainable development of the Himalayas.
Keywords: assessment; environmental; Himalayas; impact
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Ahmad, A., Rawat, J. S., & Rai, S. C. (1990). An Analysis of the Himalayan Environment and Guidelines for its Management and Ecologically Sustainable Development. Environmentalist, 10(4), 281–298.
Abstract: The impacts of human activities on the bio-geophysical and socio-economic environment of the Himalayas are analysed. The main man-induced activities which have accelerated ecological degradation and threatened the equilibrium of Himalayan mountain ecosystems are stated as: unplanned land use, cultivation on steep slopes, overgrazing, major engineering activities, over-exploitation of village or community forests, lopping of broad leaved plant species, shifting cultivation (short cycle) in north-east India, tourism and recreation. The geomorphological conditions are major factors responsible for landslides which cause major havoc every year in the area. Wild fauna, like musk deer and the snow leopard are now under threat partially due to changes in their habitat and the introduction of exotic plant species. Population pressure and migration are major factors responsible for poverty in the hills. The emigration of the working male population has resulted in the involvement of women as a major work-force. Guidelines, with special emphasis on the application of environmental impact assessments for the management of the Himalayas, are proposed. -from Authors
Keywords: environmental-assessment; human-impact; sustainable-development; management-guideline; ecological-degradation; mountain-ecosystem; impact-assessment; developing-country; asia; Himalayas; snow-leopard; snow leopard; browse; environmental; assessment; Human; impact; sustainable; development; management; guidline; ecological; degradations; mountain; ecosystem; 830
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McCarthy, K., Fuller, T., Ming, M., McCarthy, T., Waits, L., & Jumabaev, K. (2008). Assessing Estimators of Snow Leopard Abundance (Vol. 72).
Abstract: The secretive nature of snow leopards (Uncia uncia) makes them difficult to monitor, yet conservation efforts require accurate and precise methods to estimate abundance. We assessed accuracy of Snow Leopard Information Management System (SLIMS) sign surveys by comparing them with 4 methods for estimating snow leopard abundance: predator:prey biomass ratios, capture-recapture density estimation, photo-capture rate, and individual identification through genetic analysis. We recorded snow leopard sign during standardized surveys in the SaryChat Zapovednik, the Jangart hunting reserve, and the Tomur Strictly Protected Area, in the Tien Shan Mountains of Kyrgyzstan and China. During June-December 2005, adjusted sign averaged 46.3 (SaryChat), 94.6 (Jangart), and 150.8 (Tomur) occurrences/km. We used
counts of ibex (Capra ibex) and argali (Ovis ammon) to estimate available prey biomass and subsequent potential snow leopard densities of 8.7 (SaryChat), 1.0 (Jangart), and 1.1 (Tomur) snow leopards/100 km2. Photo capture-recapture density estimates were 0.15 (n = 1 identified individual/1 photo), 0.87 (n = 4/13), and 0.74 (n = 5/6) individuals/100 km2 in SaryChat, Jangart, and Tomur, respectively. Photo-capture rates (photos/100 trap-nights) were 0.09 (SaryChat), 0.93 (Jangart), and 2.37 (Tomur). Genetic analysis of snow leopard fecal samples provided minimum population sizes of 3 (SaryChat), 5 (Jangart), and 9 (Tomur) snow leopards. These results suggest SLIMS sign surveys may be affected by observer bias and environmental variance. However, when such bias and variation are accounted for, sign surveys indicate relative abundances similar to photo rates and genetic individual identification results. Density or abundance estimates based on capture-recapture or ungulate biomass did not agree with other indices of abundance. Confidence in estimated densities, or even detection of significant changes in abundance of snow leopard, will require more effort and better documentation. |
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Abdunazarov, B. B. (1990). Composition and numbers of the rare terrestrial vertebrates and prospects of their preservation in Uzbekistan. Nature reserves in the USSR: Their present and future..
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Anonymous. (1903). The Snow Leopard. Zoological Society Bulletin, Oct, 109.
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