No abstract

Microhabitat selection in patchy environments supports the co-existence of closely related species competing for resources. We examined niche partitioning in three sympatric species of pikas, Ochotona macrotis, Ochotona nubrica, and Ochotona ladacensis from Ladakh, India, that display contrasting lifestyles, social behavior and co-occur at small spatial scales. We used a classical paired quadrat approach to document biologically relevant vegetation and landscape features (niches) likely to support the presence of different species. We used a Bayesian framework to describe niche spaces , estimate niche widths and overlaps between species pairs. In addition, we used a GLM framework to identify factors that promote the presence of different species in the landscape. The rock-dwelling Ochotona macrotis was a specialist, exclusively associated with microhabitats offering a good cover of large-sized rocks and no shrubs. The social, Ochotona nubrica, was a specialist found across elevations but associated exclusively with mature stands of scrub vegetation (Caragana sp in the South-East and Hippophae sp in the North-West) occupying a unique niche. The social Ochotona ladacensis, although an elevational specialist, was likely to be found in microhabitats of other species characterised by moderate rock cover and low-lying Caragana scrublands, in addition to being found in alpine grasslands and meadows.

Exotic timber plantations have expanded in the montane habitats of the Western Ghats in the last century, often replacing the natural grassland-rainforest mosaic. This has inadvertently increased tree connectivity across the landscape, affecting arboreal mammals in varied ways. Here we report that the endemic Indian giant squirrel nests in exotic timber plantations in the Palani Hills, a behaviour not previously described. An extensive survey of timber plantations revealed a total of 70 nests, with 73% of the nests found on exotic Eucalyptus trees. An investigation of the landscape and environmental factors that were associated with the choice of nesting locations revealed that nest sites were significantly closer to rainforest patches. Squirrels also nested on east-facing slopes, away from human disturbances like agriculture. This study is the first to report giant squirrel nesting behaviour in exotic timber plantations across a landscape mosaic. We suggest that policymakers and managers proceed with caution while clearing plantations in an attempt to restore native vegetation.