Herbivores, animals that eat plants, play a crucial role in the health of a forest by maintaining the diversity of plant life. They shape the ecosystem by controlling wildfires, cycling nutrients, and maintaining vegetation dynamics. Unfortunately, they often get left behind by large carnivores when it comes to targeted conservation efforts. But increasingly, human activities in landscape modifications for development are impacting herbivore habitats and require urgent attention.
In a first study of its kind, the National Centre for Biological Sciences (NCBS) Bengaluru, a centre of the Tata Institute of Fundamental Research, has shown how change in land use patterns and roads in the central Indian landscape are disrupting genetic connectivity of two large herbivores — Gaur and Sambar.
Gaur and sambar are endemic to South and South-East Asia and rank among the top prey species for large carnivores like tigers.
For the study published in the international journal for research, Molecular Ecology, the research team comprising lead author Abhinav Tyagi, Uma Ramakrishnan, Nidhi Yadav and Awadhesh Pandit, collected hundreds of faecal samples of gaur and sambar from the tiger reserves of Kanha, Pench, Nagzira-Nawagaon, Bor and Tadoba-Andhari, besides Umred Karhandla Wildlife Sanctuary and the wildlife corridor between Kanha and Pench Tiger Reserve. They found that both species face threats such as habitat fragmentation, habitat loss, illegal poaching, and other anthropogenic impacts responsible for population decline and local extirpation.
Rising threats
Central India, like other areas of conservation concern, faces threats from growing linear infrastructure such as highways, railway lines, and changes in land use patterns, expanding road network, mining activities and other development projects. Such infrastructures hinder animal movement creating fragmented populations confined within small habitat patches disconnected from each other. Maintaining movement among habitat patches usually results in mating and genetic exchange, the loss of which can increase the probability of species extinction.
Researchers stress that Umred Karhandla Wildlife Sanctuary with a small population is the most genetically differentiated and needs conservation intervention.
Urban areas and road networks are expected to grow substantially by 2030, and human populations are also expected to increase, especially in biodiversity hotspots. The combined effects of human demographic growth, land use change, and climate change pose a serious threat to wildlife connectivity. Despite the need for development to meet India’s economic goals, it is imperative to align development with conservation objectives, says the study.