The Bandipur Tiger Reserve in Karnataka supports a healthy population of 150 tigers out of around 3,600 nationally, according to the 2022 tiger census report. “The survival of the tiger is closely tied to the survival of large-bodied prey species such as sambar deer and gaur,” says T. Ramesh, senior scientist at the Salim Ali Centre for Ornithology and Natural History (SACON).
A new study conducted under Ramesh’s guidance examines the spatio-temporal habitat suitability for gaur or Indian bison (Bos gaurus) in Bandipur, focusing on how seasonal and spatial factors influence their distribution, habitat preference, and conservation needs. “Gaur is a mixed feeder, which browses as well as grazes. Decades ago, Bandipur had good understory grassland cover beneath the trees, which sustained them well. Today, most of these grasslands have been taken over by invasive species, leaving little for gaur to feed on. This forces them to move into interface areas or zones shared by both humans and wildlife, leading to conflicts,” Ramesh explains.
Researchers conducted extensive field surveys and habitat analyses from January to December 2023. Using both direct sightings and indirect signs, along with environmental and anthropogenic data, the study aimed to identify key factors driving gaur habitat suitability and to improve management strategies for this vulnerable mega herbivore.
The lead author, Subhadra Barik, informs Mongabay India that suitable habitat for gaur has declined significantly in Bandipur, with only about 43% of the total area found to be suitable. “The suitable habitats varied across scales, ranging from 11.23% to 43.83%, with the lowest suitability in the dry season model at micro scale and the highest in the wet season model at macro scale,” the paper notes. Barik says this is concerning given that the entire area was once abundant in grass and well-suited for ungulates. While gaur are distributed throughout the park, their abundance is concentrated in areas with higher forage quality. Habitat suitability was influenced mainly by shrub cover, waterhole density, tree diversity, habitat heterogeneity, ruggedness, elevation, precipitation, and proximity to human settlements and roads.
“We found that roadside clearings play a role. Maintained for tourism and as fire lines, these areas encourage grass growth, attracting gaur and other herbivores such as spotted deer,” Barik points out. The study also found that tree diversity and ground cover—herbs and grasses—are vital for gaur occurrence, especially during the wet season when grazing opportunities and undergrowth are abundant. Invasive plant species such as lantana significantly affect habitat suitability, while precipitation enhances it during the wet season by supporting lush ground vegetation.
Barik says the findings highlight the need for better management of protected areas through restoring grasslands in less suitable areas; managing waterholes during the dry season to maintain associated grasslands and swampy areas; and extending roadside grassland management throughout the park so that forage patches are more evenly spread.
Banner image: A herd of gaur in Bandipur Tiger Reserve. Indian bisons or gaur are mixed feeders that browse as well as graze. Image by T. Ramesh
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