Tribal habits endanger Jurassic-era frog

A Jurassic-era frog species that survived more than 120 million years now faces extinction threats, because of the unique food habits of tribal communities from Kerala.

The Indian purple frog Nasikabatrachus sahyadrensis is an endemic and endangered amphibian that is found exclusively in the southern parts of the Western Ghats.

This ancient frog lineage survived for about 120 million years and even witnessed the extinction of the dinosaurs. Scientists said it belongs to an entirely new family of amphibians. Because of its declining population, the purple frog has been classified as ‘endangered’ in the red list of the International Union for the Conservation of Nature.

Five years of field study by a Delhi University team brings out evidence on how these frogs face a serious threat of getting extinct because tribal from Idukki district consumed the tadpoles as a delicacy. The practice began 40 years ago and continued in the absence of any initiative to make the tribal aware of the consequences. “The Indian Purple frog is considered a flagship species for conservation of the Western Ghats biodiversity hotspot region. This finding is an urgent wake up call to conservation professionals,” says Ashish Thomas, a Delhi University scientist associated with the study.

The field survey found that on an average, a household of four people consumes approximately 3 kg (1,500 pieces) tadpoles per season. Tadpoles are always consumed fresh after harvesting and never stored for later use.

The tadpoles are cooked and usually eaten with boiled rice or tapioca. For a family of four, about 300 tadpoles are used for a single meal. Since they are available only for a short period every year, they are considered a delicacy.

“Purple frog now perilously survives in few pockets. If the purple frog tadpoles continue to be on the tribal menu as a monsoon delicacy, their local population are destined to disappear”, said S D Biju, a Delhi University professor and the team leader.

Frog harvesting and trade, which used to be a common practice in India, have been banned since 1987. But since many tribal communities don’t know the rules, improving their awareness is vital for their conservation, suggested Biju who was one of the discoverers of these frogs in 2003. “In the distant past when the purple frog was neither rare nor endangered, this practice may not have made a significant dent in the overall population. But times have changed,” he added.