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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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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.
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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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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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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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Wolf, M., & Ale, S. (2009). Signs at the Top: Habitat Features Influencing Snow Leopard Uncia Uncia Activity in Sagarmatha National Park, Nepal. Journal of Mammalogy, 90(3), 604–611.
Abstract: We used logistic regression to examine factors that affected the spatial distribution of sign (scrapes, feces, footprints, spray or scent marks, and rubbing sites) in a newly reestablished population of snow leopards (Uncia uncia) in Sagarmatha (Mount Everest) National Park, Nepal. Our results indicate that terrain and human activity were the most important factors determining the spatial distribution of leopard activity, whereas presence of their major prey species (Himalayan tahr [Hemitragus jemlahicus]) had only a moderate effect. This suggests that localities at which these animals are active represent a trade-off between suitable habitat and avoidance of potential risk from anthropogenic origins. However, the influence of prey presence was likely underestimated because of the methodology used, and likely weighed in the trade-off as well.
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Ferretti, F., Lovari, S., Minder, I., Pellizzi, B. (2014). Recovery of the snow leopard in Sagarmatha (Mt.Everest) National Park: effects on main prey. European Journal of Wildlife Research, (60), 559–562.
Abstract: Consequences of predation may be particularly
heavy on small populations of herbivores, especially if they
are threatened with extinction. Over the 2006–2010 period, we
documented the effects of the spontaneous return of the endangered
snow leopard on the population of the vulnerable
Himalayan tahr. The study area was an area of central
Himalaya where this cat disappeared c. 40 years before, because
of persecution by man. Snow leopards occurred mainly
in areas close to the core area of tahr distribution. Tahr was the
staple (56.3 %) of snow leopards. After the arrival of this cat,
tahr decreased by more than 2/3 from 2003 to 2010 (mainly
through predation on kids). Subsequently, the density of snow
leopards decreased by 60%from2007 to 2010. The main prey
of snow leopards in Asia (bharal, marmots) were absent in our
study area, forcing snow leopards to specialize on tahr. The
restoration of a complete prey spectrum should be favoured
through reintroductions, to conserve large carnivores and to
reduce exploitation of small populations of herbivores, especially
if threatened.
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Schaller, G. B., & Mirza, Z. B. (1971). On the behaviour of Kashmir Markhor (Capra falconeri cashmiriensis). Mammalia, 35, 548–566.
Abstract: Notes snow leopard as main predator in Pakistan study area. Describes content of some snow leopard droppings
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Schaller, G. B. (1972). On the behaviour of Blue Sheep (Pseudois nayaur). Journal of Bombay Natural Historical Society, 69, 523–537.
Abstract: Two or three snow leopards hunted in the study area in eastern Nepal. Describes content of some snow leopard scat
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