ABUNDANCE OF ROYLE’S PIKA (OCHOTONA ROYLEI) ALONG AN ALTITUDINAL GRADIENT IN UTTARAKHAND, WESTERN HIMALAYA

gradient from 2900 to 3650 m a.s.l. Pikas ’ detection probability and relative abundance per month and habitat were recorded by monthly surveys consisting of three sampling sessions of four hours each. Food plant species were identified by visual observation and quantified by a standard quadrat method. The highest relative abundance was observed at man-made walls and surroundings in the alpine zone and on broken slopes in the sub-alpine one, whe-reas alpine meadows showed the lowest abundance. A total of 26 plant species were found to be consumed by pikas. The proportion of forage plants was the highest (77.4%) on the rocky slopes of the timberline zone The results of multiple regressions suggest that rock cover is the main factor affecting the relative abundance of Royle’s pika. Rocky areas prob-ably offer both nest-sites and temporary refuges to escape from predators