Researchers identify genetic differences in the species, warning against unscientific release of confiscated animals
The Indian star tortoise (Geochelone elegans), with its striking black shell marked by star-like yellow patterns, is both an iconic symbol of the Indian subcontinent and a victim of illegal wildlife trade. While they are hardy herbivores and often kept as exotic pets, the Indian star tortoise is critically endangered in the wild and should not be kept as pets. In India, owning one is illegal, and its increasing popularity as a pet has led to its entanglement in one of the world’s largest wildlife trafficking networks.
Native to arid regions of northwest India, southern India, and Sri Lanka, the Indian star tortoise is not only a beloved species but also an endangered one. Despite legal protections, including being listed under CITES Appendix I and Schedule I of India’s Wildlife Protection Act of 1972, the tortoises continue to be smuggled across borders, with hundreds of individuals seized this year at major hubs like the Chennai and Singapore airports, and even at the India-Bangladesh border.
In response to these alarming trends, experts are now warning against releasing confiscated tortoises back into the wild without scientific consideration. Sneha Dharwadkar, a wildlife biologist and co-founder of the NGO Freshwater Turtles and Tortoises of India, cautioned against such unscientific releases. “We can no longer simply take confiscated tortoises and release them into nearby forests,” she said, highlighting the need for a more targeted and informed approach.
In an effort to develop a more effective strategy for conservation, a recent study by researchers from the Wildlife Institute of India (WII) and Panjab University has explored the genetic diversity and natural distribution of Indian star tortoises. The study revealed that the species comprises two genetically distinct groups: one from the northwestern regions of India and another from the southern parts of the country. These findings suggest that conservation and reintroduction efforts must be region-specific, taking into account the genetic variations within the species.
Subhasree Sahoo, a PhD student at WII and the study’s lead author, explained that the genetic differences were not just academic but could influence the physical characteristics of the tortoises. Understanding these genetic distinctions could help guide where and how confiscated individuals should be released in order to enhance their chances of survival. “These genetic divergences could inform strategies for the release and conservation of rescued tortoises,” Sahoo said.
Millions of years ago, the Indian subcontinent was home to a variety of tortoises, including the Indian star tortoise. The landscape of the subcontinent has undergone significant transformation since then, with the separation of humid forests and dry savannahs. This shift created two distinct ecological zones, one in the northwest and the other in the south, which, over time, became home to two genetically distinct populations of the Indian star tortoise. This split, researchers believe, happened around two million years ago.
To gather genetic evidence for this historical division, the study team collected tissue samples from tortoises in 14 locations across India, including wildlife reserves and protected areas. Sahoo, who conducted fieldwork in some of the most remote areas, explained that collecting samples during the rainy season was crucial, as this is the tortoises’ breeding period and they are most active. Local communities and frontline forest staff assisted in the collection of 38 samples from northwestern India and 44 from the southern regions.
The study faced significant challenges, particularly in obtaining blood samples, as even small mistakes during blood collection can cause bleeding. In controlled environments like zoos, this is manageable, but it becomes much harder in the wild. “When I was in Kakatiya Zoo in Telangana, a zookeeper suggested, ‘Madam, why do you want to take blood? You can take the scutes (the keratin layers on the tortoises’ limbs and shells) instead. They come off easily,'” Sahoo recalled. The technique worked, and researchers were able to extract DNA from these scute samples, which were later tested in the laboratory.
After extracting the DNA, the researchers sequenced mitochondrial genes, including cytochrome B and NADH dehydrogenase 4, which are crucial for identifying subspecies-level differentiation. The study’s findings underscore the importance of a region-specific approach when it comes to the conservation of the Indian star tortoise.
The study’s results provide critical insights into the conservation of this species, emphasizing the need for careful consideration of genetic differences when planning the release and rehabilitation of confiscated tortoises. As global wildlife trafficking continues to threaten the survival of this remarkable species, a more scientifically informed approach to conservation will be vital in ensuring the future of the Indian star tortoise in the wild.
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