2.7.1 Conversion of Prey Biomass
An estimate of biomass consumed by snow leopard was used rather than occurrence percentage, as diet quantification may be more reliable (Wegge et al., 2012). Smaller animals, for example, are usually over-represented in the scat analysis (Floyd et al., 1978). Frequency of occurrence of individual prey items are converted to biomass and numbers consumed according to the relationship between scat production and prey size (Ackerman et al., 1984; Floyd et al., 1978) in the following way: Y = 1.980 + 0.035 X, where Y is weight of prey consumed per scat, and X is the live weight of particular prey (in kg).
To quantify the predation rate of a snow leopard, average consumption rates per day of wild (Naur) and domestic livestock were used following Oli (1993) and Wegge, et al. (2012) as follows: Naur 34 kg, Yak 150 kg, horse/cattle 140 kg, goat 25 kg, and sheep 30 kg. Of large prey, predators did not consume the whole ungulate carcass due to inedible parts such as skeletal pieces, horns/antlers, rumen content and parts of the skin (Floyd et al., 1978). It was assumed that snow leopards consumed the following proportional weights of domestic and wild ungulate as described by Oli et al. (1993) and Wegge et al. (2012): Naur 75%, yak 50%, horse and cattle 60% and sheep and goat 70%.
A G-Test was employed to determine if snow leopard have a preference for certain species according to their availability across the study sites (Manly et al., 2007). To determine if particular species will be preferred, less preferred or avoided, a 95% confidence interval was created for each category by applying Bonferroni corrections to the Z-statistic (Neu et al., 1974).
Results
3.1 Snow Leopard Abundance
Out of 88 putative samples, 73 (83%) were confirmed by genetic analyses to be from snow leopard. Among snow leopard positive samples, 60% (44) were successfully genotyped. Fecal DNA analysis identified 19 individual snow leopards (nine females and ten males) (Table 1; Fig. 2). GPS locations of individually identified snow leopards were plotted on digital topographic maps in ArcView 3.1 (Fig. 2) to calculate the survey area of sample collection. The mean maximum linear distance moved by individual snow leopards was calculated at 3.3 km (std. error 0.6) with a buffer strip width of 1.6 km. The program SPACECAP estimated a mean snow leopard population size of 24 (95% CI: 19-29; SD: 3.04). The mean density was 3.9 individuals/100 km2 (95% CI: 3.1- 4.8; SD: 0.8; Table 1) for the survey area of 609 km2. Khambachen block had a higher number of snow leopards, followed by Ramjer (eastern part of Khambachen), Yagma and Gola (both blocks lies north-western part of Khambachen).
The encounter probability was 1.73 (95% CI: 0.21-1.19). Detection probability at trap locations was found to be 0.05 and the Psi, the ratio of the number of animals actually present within the space to the maximum allowable number, was 0.08. The number of effective alleles (Ae) was 2.4 (se±0.18) and observed heterozygosity (Ho) was 0.57 (se±0.08) in six polymorphic loci.