Endangered crowned river turtles, Hardella thurjii (H. thurjii), are facing a rising and unexpected threat from golden jackals in the Keoladeo National Park (KNP) in Bharatpur, Rajasthan. A recent study by researchers from Sálim Ali Centre for Ornithology and Natural History (SACON) documented 48 predation events, where the jackals captured and killed the turtles, over just five months, from August to December 2023, raising fresh concerns about the turtle population’s long-term survival. The findings challenge long-held assumptions about predator-prey dynamics in protected areas, where native predators like jackals are typically seen as part of a balanced ecosystem. However, in this case, unchecked predation — especially targeting nesting females — could contribute to the local extinction of an already vulnerable species.

According to Aditi Mukherjee, a scientist and the corresponding author of the study, the range of H. thurjii is largely confined to the upper Gangetic basin, and Bharatpur marks the western limit of its known distribution. “There’s still a major gap in our understanding of the species’ natural history, habitat use, and nesting patterns in this region,” she explains.

Already threatened by habitat loss, poaching, and the pet trade, H. thurjii has been classified as endangered in the IUCN Red List. “H. thurjii has historically been hunted for its meat due to its large size and also faces habitat loss from dam construction, which may further be restricting its distribution,” says Ramya Roopa, a researcher with Wildlife Conservation Trust, who is not associated with the SACON study.

Although earlier reports suggest that KNP has the highest density of jackals among India’s protected areas, little is known about their feeding behaviour and interactions with reptiles. While studying Indian pythons and their interactions with prey, including jackals, the researchers unexpectedly observed a sudden spike in H. thurjii mortalities. After encountering six deaths in just three days, they began systematically monitoring areas where the jackals were preying on the turtles.

A native predator threatens an endangered prey

Predators are vital in regulating prey populations and maintaining ecosystem balance. However, ‘depensatory predation’, where predation pressure intensifies as prey numbers decline, can drive vulnerable species toward local extinction. With only a few natural threats and a favourable environment, jackal numbers in KNP have been steadily rising, amplifying their impact on sensitive prey species.

Unlike other turtles in Keoladeo, H. thurjii may travel as far as one kilometre, often navigating trails and roads in search of nesting sites within the wetland’s mosaic landscape — a trait that increases their risk of being preyed on during the breeding season. According to Mukherjee, females typically remain underwater and only emerge during the egg-laying season, migrating from feeding grounds to nest on sandbanks. Each female may lay up to 100 eggs, often in multiple clutches.

Asmita Ranapaheli, an IUCN SSC Tortoise and Freshwater Turtle Specialist, points out that unlike many freshwater turtles that lay eggs in a single clutch, female H. thurjii lay eggs almost daily during the nesting period. “This continuous nesting behaviour, combined with their large size and conspicuous eggs in the open sandy nesting grounds of Keoladeo National Park, makes them highly vulnerable to predation by jackals and other scavengers,” she says.

According to Mr Manas Singh, IFS, Deputy Conservator of Forest, Keoladeo National Park, the forest department officials noted an increase in the movement of female turtles during the late night and early morning hours. “Using camera traps and by tracking turtle marks, we identified sites where predation incidences were occurring,” he says.

Gourav Sonawane, a Ph.D. student and the lead author of the study, recalls encountering multiple turtle deaths between September and January, the peak nesting season. Camera trap images, analysis of carcasses, and observations from the Keoladeo National Park’s Forest Department staff and local guides all revealed a spike in jackal activity near the turtles’ nesting sites during the same period.

Using these insights, researchers mapped key predation hotspots, which were concentrated along the roads that cut through the park’s wetland areas. “We observed the maximum turtle deaths on tracks around a pond near the Keoladeo temple, which retains water year-round and may serve as a key nesting site for the turtles,” Sonawane adds.

Jackal-turtle interactions 

While KNP has ample prey for its growing jackal population, migrating turtles offer an easy target. Mukherjee explains that jackals do not have to chase or struggle with turtles, making them a low-effort and easily accessible secondary prey. “H. thurjii being a hard-shelled turtle, cannot recover once overturned, especially on hard surfaces like roads,” Sonawane adds.

In the 48 instances documented, the researchers noted that jackals would flip the turtle over and drag them by their hind legs to a suitable feeding spot, demonstrating a specialised predation strategy. They typically began feeding on the hind legs to access soft tissue but often left the carcass partially uneaten. On several occasions, the researchers observed scavengers, including mongoose, Bengal monitor lizards and even an Indian flapshell turtle, feeding on the remains and internal organs of H. thurjii that were inaccessible to the jackals. Notably, all but one of the carcasses belonged to female turtles. Several contained up to 15 eggs, while others were found amidst scattered eggshells, clearly suggesting that gravid females were specifically targeted.

Ecological implications and conservation approaches

Preying on nesting females is a serious threat to H. thurjii’s survival in KNP. As a highly sensitive species, turtles may require extended periods to recover from such significant population losses.

Mukherjee says that increased vigilance during critical periods of turtle migration, particularly in the hotspots or near nesting sites, can reduce predation and enable safe turtle movements. Placing temporary barricades around nests and providing urgent medical care to injured turtles can further minimise mortality and support breeding success.

Singh responds, “Following the installation of fences along the corridors used by turtles and around nesting sites to curb the movement of jackals, and proper monitoring, we are observing a decrease in turtle mortalities.”

Sneha Dharwadkar, the co-founder of Freshwater Turtles and Tortoises of India, recommends allocating resources to increase the patrol for nesting areas and protecting the nests in-situ wherever they are found, without translocating them or disturbing the eggs. “For temperature-dependent sex determinant species like turtles, improper egg translocation could severely impact the demographics of the species. Therefore, it is ideal to avoid translocation or consider ex-situ conservation measures until the species’ ecology is well understood,” she adds.

Dharwadkar also points out that reliable and detailed studies on H. thurjii‘s ecology and population demography are currently lacking. Long-term studies will enhance our understanding of the species and guide further management strategies, she says.

“In the long-term, research on nesting ecology, captive assurance programmes, and population monitoring will be critical for the recovery of this endangered species,” notes Ranapaheli.

Read more: Tracking critically endangered turtles in the Ganges

Editor’s note: The story was updated on November 13, 2025 to include the Deputy Conservator of Forest’s quotes.

Banner image: A camera trap image captures a pack of golden jackals feeding on a crowned river turtle. Image by Gourav Sonawane.

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Priyanka Shankar Editor

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BiodiversityEcologyEndangered speciesMammalsProtected AreasReptilesRajasthan

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