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.

Abstract: Three mature nulliparous female leopards were studied for 5 years. During three separate 6-month periods serum oestradiol and progesterone concentrations were measured at weekly intervals. Oestradiol was elevated over 21 pg/ml for 54 weeks during these 3 periods, and 36 oestradiol peaks (65\m=.\8\m=+-\6\m=.\3pg/ml (mean \m=+-\s.e.m.), range 21\p=n-\172pg/ml) were identified. Daily frequency of feline reproductive behaviours averaged over each week increased from 1\m=.\9\m=+-\0\m=.\2(n = 93) during weeks with low serum oestradiol concentrations (<21 pg/ml) to 5\m=.\3\m=+-\0\m=.\6(n = 54) during weeks when serum oestradiol concentrations (>21 pg/ml) were high. Increased serum progesterone concentrations (13\p=n-\98n/gml) were observed on 5 occasions in 2 leopards housed together. These presumptive luteal phases lasted from 1 to 5 weeks. Baseline progesterone values were 1\m=.\6\m=+-\0\m=.\4 ng/m(nl= 131). No progesterone increments were observed in isolated animals, and serum concentrations remained at baseline levels. These limited observations suggest that female leopards do not require intromission to induce ovulation and luteal function. The average interval between oestradiol peaks for cycles with no progesterone increment was 3\m=.\4weeks (range 1\p=n-\6weeks). The interval for the 3 complete cycles associated with elevated progesterone concentrations was 7\m=.\3weeks. Analysis of sexual behaviours over the 5-year study period revealed no evidence of seasonality in these
captive leopards.

Abstract: The snow leopard faces multiple threats in the Himalayan region, from habitat degradation, loss of prey, the trade in pelts, parts and live animals, and conflict with humans, primarily pastoralists. Consequently, the populations are considered to be in decline and the species is listed as Endangered in the IUCN's Red List. As a 'flagship' and 'umbrella' species the snow leopard can be a unifying biological feature to raise awareness of its plight and the need for conservation, which will benefit other facets of Himalayan biodiversity as well. Some studies of snow leopards have been conducted in the Himalayan region. But, because of its elusive nature and preference for remote and inaccessible habitat, knowledge of the ecology and behaviour of this mystical montane predator is scant. The available information, however, suggests that snow leopards occur at low densities and large areas of habitat are required to conserve a viable population. Thus, many researchers and conservationists have advocated landscape-scale approaches to conservation within a regional context, rather than focusing on individual protected areas.This regional strategy for WWF's snow leopard conservation program is built on such an approach. The following were identified as important regional issues: 1) international trade in snow leopards and parts; 2) the human-snow leopard conflict; 3) the need for a landscape approach to conservation to provide large spatial areas that can support demographically and ecologically viable snow leopard metapopulations; 4) research on snow leopard ecology to develop long-term, science-based conservation management plans; and 5) regional coordination and dialog. While the issues are regional, the WWF's in the region have developed 5-year strategic actions and activities, using the regional strategies as a touchstone, which will be implemented at national levels. The WWF's will develop proposals based on these strategic actions, with estimated budgets, for use by the network for funding and fund-raising. WWF also recognizes the need to collaborate and coordinate within the network and with other organizations in the region to achieve conservation goals in an efficient manner, and will form a working group to coordinate activities and monitor progress.