Studying the genetic variation among different species distributed across their core and range‐edge habitats can provide valuable insights into how genetic variation changes across the species' distribution range. This information can be important for understanding local adaptation, as well as for conservation and management efforts. In this study, we have carried out genomic characterization of six species of Asian Pikas distributed along their core and range‐edge habitats in the Himalayas. We utilized a population genomics approach using ~28,000 genome‐wide SNP markers obtained from restriction‐site associated DNA sequencing. We identified low nucleotide diversity and high inbreeding coefficients in all six species across their core and range‐edge habitats. We also identified evidence of gene flow among genetically diverse species. Our results provide evidence of reduced genetic diversity in Asian pikas distributed across the Himalayas and the neighboring regions and indicate that recurrent gene flow is possibly a key mechanism for maintaining genetic diversity and adaptive potential in these pikas. However, full‐scale genomics studies that utilize whole‐genome sequencing approaches will be needed to quantify the direction and timing of gene flow and functional changes associated with introgressed regions in the genome. Our results represent an important step toward understanding the patterns and consequences of gene flow in species, sampled at the least studied, yet climatically vulnerable part of their habitat that can be further used to inform conservation strategies that promote connectivity and gene flow between populations.

The most reported elevation gradients in species richness are a unimodal peak and linear decline. However, the overlap of different biogeographic realms in a region can influence such gradients. We used live-capture data on small mammals (voles, rats, mice, shrews, and pikas) to describe elevation gradients in species richness in Sikkim, where Afrotropical, Indo-Malayan, and Palearctic fauna occur in the lower, middle, and higher elevations, respectively. We sampled 38 trap lines in an elevation range of 300 m to 4,200 m, which we binned into nine elevation zones. Each trap line had 50 Sherman traps run for 3–5 nights during 2003–05 and 2012–13. We had a total of 9,069 trap nights with 430 captures, including 13 species of murid rodents, five ground shrews, two voles, and one each of pika and tree shrews. The capture rate in a trap line ranged from 0 to 19.7 per 100 trap night (mean = 5.30±0.767 SEM) with a peak at 2,501–3,001 m (3.29±0.644), coinciding with temperate broad leaf and conifer forests. Species richness seemed to have a minor peak at 501–1,000 m (2.50±0.645 species per trapline) and a clear peak at 3,001–3,500 m (3.29±0.644), coinciding with tropical forests and temperate mixed conifer forests, respectively. The apparent bimodal elevation gradient is due to the overlap of western Asian and Indo-Malayan fauna in the lower elevation and of the latter and Palearctic fauna in the higher elevation. More intensive sampling is needed to test this hypothesis that the overlap of biogeographic regions can influence elevation gradient in species richness.