- A new study suggests that habitat degradation has reduced the suitability for rhinos in Babai Valley of Nepal’s Bardiya National Park, forcing them to range widely.
- Researchers note that prolonged dry periods in the area could potentially increase ecological stress by reducing access to water, forage and wallowing sites.
- Locals say that many rhinos are now sighted in community forests in the fringes of the national park, with sporadic incidents of human-wildlife conflict.
- Experts stress that translocation is not simply about releasing animals and that long-term post-release monitoring is needed to assess behavioral patterns and identify necessary interventions.
KATHMANDU — Nepal’s ambitious efforts to establish a viable population of the vulnerable greater one-horned rhinoceros in western Nepal’s Bardiya National Park 40 years ago has been seen as a conservation success. The park, which didn’t have a surviving population until the 1980s, is now home to 38 individuals, as per recent census.
But a new study shows that the translocated animals are wandering far outside their release zones in search of food and water, suggesting the habitat may not be healthy enough to keep them there.
Researchers, who GPS collared five of the eight animals translocated from Chitwan in central Nepal in 2016-17, found that the larger home range of the reintroduced rhinos (Rhinoceros unicornis) in Babai Valley (one of the two habitats, the other one being the banks of Karnali River) of Bardiya National Park was primarily due to limited grassland, fragmented riverine forests and seasonal scarcity of water and forage.
“Habitat degradation from floods further reduced suitability, forcing rhinos to range widely,” the study said. “Given the small population size and fragmented habitat, Babai Valley may not support a viable rhino population without significant habitat restoration, addition of individuals, or relocation to more suitable sites.”
Once confined to Chitwan National Park — the heartland of Nepal’s rhino population — a smaller number of animals were relocated to Bardiya and Shuklaphanta national parks in the late 1980s to expand their range. But heavy poaching and weak security during the decadelong Maoist insurgency, which started in 1996, took a devastating toll.
Nepal’s rhino population almost halved from 612 in 2000 to 375 in 2005, while Bardiya’s number fell from 67 to 22 by 2008, prompting authorities to relocate another nine rhinos in the latter decade to revive their population. The latest 2021 census shows the park is now home to 38 rhinos, with Nepal’s national population reaching 752 — a 16.6% increase compared to 2015.
Despite the gains, however, researchers say that the habitat use and distribution of translocated rhinos remain poorly understood. But they add the use of GPS tracking in the recent study to track the rhinos hourly for about a year has provided more detailed insights than the very high frequency (VHF) collars previously used to monitor relocated animals.
Babu Ram Lamichhane, co-author of the study who currently associated with the nonprofit Wild Care Nepal, said their study demonstrates that floodings, particularly in 2015 and 2017, have inundated large areas of the Babai Valley. He said this has reduced grassland patches and limited wallowing sites, which the rhinos prefer, within the narrow valley, causing the animals to roam beyond their normal range.
“We are seeing the impacts of water deficit in the Babai River, especially during the dry season, in the life cycle of rhinos,” Lamichhane said. “They’re gradually shifting their habitat for wallowing and securing food sources, as far as moving to India’s Katarniaghat Wildlife Sanctuary, where it’s flatter and [which] has more water availability. The rhino habitat is not at an optimal level in Babai Valley.”
Water is a critical resource for rhinos, not only for drinking but also for thermoregulation and skin maintenance through wallowing, with prolonged dry periods potentially increasing ecological stress by reducing access to water, forage and wallowing sites. This could potentially force rhinos to travel longer distances and spend more energy, according to Balram Awasthi, a rhino researcher who holds a doctorate from the Chinese Academy of Sciences’ Xishuangbanna Tropical Botanical Garden, where he studied the ecosystem functions of rhinos in Nepal.
He said that while Chitwan provides extensive alluvial floodplains with large contiguous grasslands, abundant wetlands and relatively stable riverine forests, which in turn provides high-quality forage and water year-round for the rhinos, Babai Valley, in contrast, has narrower floodplains, more fragmented grassland patches and greater seasonal variation in water and forage availability.
“These differences influence rhino ecology, and these habitat differences directly affect rhino behavior,” Awasthi said. “Bardiya has potential, but it’s still uncertain whether Babai currently has enough high-quality grassland and dry-season resources to support a much larger self-sustaining rhino population.”
Relocations are a common conservation tool to revive populations of vulnerable and endangered species, though Nepal has had mixed results with that practice. The translocation of rhinos from Chitwan to other locations has been largely successful, at least population-wise, though there have been concerns.
The transfer of wild water buffaloes (Bubalus arnee) from Koshi Tappu Wildlife Reserve in eastern Nepal to Chitwan National Park in 2017 faced setbacks, with the entire introduced population eventually dying. More recently, a proposed blackbuck (Antilope cervicapra) relocation plan from Bardiya to Chitwan has also raised red flags over habitat suitability.
“Overall, Nepal’s rhino reintroduction can be considered successful, but continued habitat restoration and management will be essential to ensure these populations become fully self-sustaining in the long term,” Awasthi said. “Conservation success should not be measured only by population numbers, but also by the health and resilience of the habitats that support them.”
In Bardiya, locals are already witnessing the effects of habitat degradation on the rhinos.
Manju Mahatara, a wildlife guide with eight years of experience, said that wallowing sites that once existed along riverbanks and grassland areas are now largely dry. This, she added, has forced rhinos to seek new habitats beyond the national park.
“Before, we used to spot six to seven rhinos within the core park area, but these days we hardly sight one,” she said. “Many rhinos were released in the Babai Valley, but it’s difficult to spot them these days.”
Mahatara said that many rhinos are now sighted in community forests in the fringes of the national park, with sporadic incidents of human-wildlife conflict. She said the rhinos usually enter farmlands and destroy crops during harvest season, while in a rare incident, a nature guide was killed in a rhino attack in the Dalla community forest two years ago.
With new evidence suggesting habitat degradation in Babai and that “rhinos may still be exploring new suitable environments and searching for mates,” Lamichhane said the authorities should start prioritizing other areas that could be more conducive for the species. He said the Karnali floodplain, adjacent to Bardiya National Park, could offer a better alternative for establishing a viable population of more than 50 rhinos, as well as Shuklaphanta National Park and Koshi Tappu Wildlife Reserve, which currently are home to a small population of around 17 and two individuals, respectively.
Meanwhile, authors of the study say that translocation is not simply about releasing animals, and that long-term post-release monitoring is needed to assess behavioral patterns and identify necessary interventions. Some experts also argue that early rhino translocations in Bardiya, carried out before the armed conflict ended, were done hastily, with officials wanting “quick results and not enough studies.”
In recent years, more studies and coordinated efforts by conservationists and government officials have improved understanding of rhino translocations and provided vital lessons for future relocations. However, Awasthi said, it is also crucial to study the movement, habitat use and survival of calves born and raised in the new habitat to assess true adaptation. Referring to the collared rhinos in Babai, he said that the adults were translocated from Chitwan and may still be searching for the grasslands and riverine habitats they previously inhabited.
“Future translocations should also assess whether rhinos are restoring their ecological roles as megaherbivores and ecosystem engineers,” Awasthi said. “By shaping vegetation structure, maintaining grassland dynamics, dispersing seeds and creating habitat heterogeneity, rhinos contribute to broader ecosystem functioning. Therefore, success should be measured not only by survival and reproduction, but also by ecological impact.”
Banner image: A greater one horned rhino eats water plants from a river in Janakauli community forest bordering Chitwan National Park, 2010. Image by AP Photos/Gemunu Amarasinghe.
Nepal’s rhino translocations to continue amid concerns over effectiveness
Citations:
Ranabhat, R., Pandey, H. P., Ghimire, S. K., Subedi, N., Lamichhane, B. R., KC, K. B., & Maraseni, T. N. (2026). Movement ecology and habitat preferences of translocated greater one-horned rhinoceros in their historic range in Nepal. Journal for Nature Conservation, 92, 127302. doi:10.1016/j.jnc.2026.127302
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