Abundance estimates of wild prey (Blue sheep Pseudois nayaur and Ibex Capra sibirica) using double observer surveys. C is the number of groups seen by both observers, S1 is the
number of groups seen by first observer only, S2 is the number of groups seen by second observer only, bG is the estimated number of groups, N is estimated population size and P1,
P2 are detection probabilities for observer one and two respectively. The surveys were conducted twice during the study period.