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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Ale, S. B., Brown, J.S. (2009). Prey behavior leads to predator: a case study of the Himalayan tahr and the snow leopard in Sagarmatha (Mt. Everest) National Park, Nepal. Israel Journal of Ecology & Evolution, 55(4), 315–327.
Abstract: Rare, elusive predators offer few sightings, hindering research with small sample sizes and lack of experimentation. While predators may be elusive, their prey are more readily observed. Prey respond to the presence of a predator, and these fear responses may have population- and community-level consequences. Anti-predator behaviors, such as vigilance, allow us to sidestep the difficulty of direct field studies of large predators by studying them indirectly. Here we used a behavioral indicator, the vigilance behavior of the Himalayan tahr, the snow leopard’s main local prey, to reveal the distribution and habitat use of snow leopards in the Mt. Everest region of Nepal. We combined techniques of conventional field biology with concepts of foraging theory to study prey behavior in order to obtain insights into the predator’s ecology. The Himalayan tahr’s vigilance behavior correlates with the distribution of snow leopard signs. Tahr actually led us to six sightings of snow leopards. We conclude that behavioral indicators provided by prey offer a valuable tool for studying and monitoring stealthy and rare carnivores.
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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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Ale, S., Shrestha, B., and Jackson, R. (2014). On the status of Snow Leopard Panthera Uncia (Schreber 1775) in Annapurna, Nepal. Journal of Threatened Taxa, (6(3)), 5534–5543.
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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.
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Schutgens, M. G., Hanson, J. H., Baral, N., Ale, S. B. (2018). Visitors’ willingness to pay for snow leopard Panthera uncia conservation in the Annapurna Conservation Area, Nepal. Oryx, , 1–10.
Abstract: The Vulnerable snow leopard Panthera uncia experiences
persecution across its habitat in Central Asia, particularly
from herders because of livestock losses. Given the
popularity of snow leopards worldwide, transferring some
of the value attributed by the international community to
these predators may secure funds and support for their conservation.
We administered contingent valuation surveys to
 international visitors to the Annapurna Conservation
Area, Nepal, between May and June , to determine
their willingness to pay a fee to support the implementation
of a Snow Leopard Conservation Action Plan. Of the %of
visitors who stated they would pay a snow leopard conservation
fee in addition to the existing entry fee, the mean
amount that they were willing to pay was USD  per trip.
The logit regression model showed that the bid amount, the
level of support for implementing the Action Plan, and the
number of days spent in the Conservation Area were significant
predictors of visitors’ willingness to pay. The main reasons
stated by visitors for their willingness to pay were a
desire to protect the environment and an affordable fee. A
major reason for visitors’ unwillingness to pay was that
the proposed conservation fee was too expensive for them.
This study represents the first application of economic valuation
to snow leopards, and is relevant to the conservation of
threatened species in the Annapurna Conservation Area
and elsewhere.
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Jackson, R. M., Ahlborn, G., Gurung, M., & Ale, S. (1996). Reducing livestock depredation losses in the Nepalese Himalaya. Proc.Vertebr.Pest Conf, 17, 241–247.
Abstract: The authors investigated livestock depredation patterns of snow leopards on the northern slopes of the Himalayans near the villages of Manang and Khangshar, Nepal. Information is discussed on the relationships among livestock loss, endangered species management, public relations/conservation issues, and cooperative efforts among institutions involved in the decision making process. A plan is devised for alleviating livestock loss and protecting endangered species in the area. pcp
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Ale, S. B. (1998). Religion and Snow Leopards in Nepal (Vol. xvi). Seattle: Islt.
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