Sympatric pikas partition microhabitats differently across a spatial-elevational gradient.

How closely related, ecologically similar species co-occur and navigate competition remains a central question in community ecology. Microhabitat partitioning in patchy environments can support the co-existence of sympatric species on small spatial scales. We quantified niche spaces and directional niche overlaps of three cold-adapted, high-altitude pikas (Ochotona spp.) from the Trans-Himalayas to understand their responses to interspecific competition across elevational and spatial scales. Vegetation- and landscape-level features were documented across elevational bands. The social, burrowing O. nubrica preferred tall stands and high shrub cover on pastures (2800-4500 m). Conversely, the social, burrowing O. ladacensis emerged as a high-elevation specialist (4200-6000 m), occupying stunted alpine scrub and steppes. The asocial, rock-dwelling O. macrotis preferred microhabitats with high rock cover across elevations (2800-6000 m), associating with significantly greener microhabitats at lower elevations in summer. Visualizing directional niche overlaps revealed scale-dependent patterns of niche segregation; species functioning as generalists at large spatial scales behaved as specialists at smaller scales. As climate change and shifting land-use patterns threaten cold-adapted Himalayan specialists, this nuanced understanding of microhabitat associations in sympatric zones is vital for informing conservation planning.