Geography of mammalian herbivores in the Indian Trans-Himalaya : patterns and processes

Animals need adequate resources so that their populations not only survive but thrive. So they seek places that can best provide them. Yet, they face several challenges, while obtaining these resources, e.g., predators, competitors and physical obstacles: mountains and rivers. Some animals are better-equipped to overcome these challenges, and are widely distributed, while others are not. These differences generate uneven pattern of distribution of life on earth. Tsewang Namgail’s study on the mammalian herbivores in the arid regions of the Himalayan mountains shows that interspecific competition is a major factor determining distribution and diversity patterns of these animals. Topography is also an important factor determining their coexistence, and thus it plays a crucial role in the formation and maintenance of herbivore assemblies in these drier, alpine regions. The study highlights that herbivores change their diet spectrum in response to the number of other herbivore species in an assemblage, and therefore emphasizes the inclusion of interspecific interactions in species distribution models.