Caught between myth and climate change: Can 'Mahabali' save this frog from extinction?

Legend has it that the mythical monarch Mahabali, the just ruler who made even the gods envious, returns to Kerala from the nether world every year in Onam. Up in the mountain ranges of the Western Ghats, his four-legged namesake emerges from its underground kingdom just once a year. And like the maharaja of the epics, the amphibian stays in the open for a few hours before returning to where it came from.

The 'Nasikabatrachus sahyadrensis', commonly called as the purple frog and popularly known as the Mahabali frog, is one of the rarest and most enigmatic amphibians in the world, found only in the lush green hills of the Western Ghats in Kerala.

Discovered only in October 2003 by biologists S D Biju and Franky Bossuyt, this frog is anything but the colourful or vibrant species found in the forests. With its bloated body, sturdy and short limbs, a pointed snout and pig-like appearance, it earned the nickname 'pignose' frog. Its unusual looks, which defied the often celebrated charm of amphibians, remained an obstacle in garnering public sentiment in its conservation efforts.

Finding a place in the endangered category of the International Union for Conservation of Nature's (IUCN) Red List, a campaign to aid the purple frog's conservation and survival became paramount. It was around this time that Dr Sandeep Das, research associate, Department of Biotechnology at University of Calicut, and one of the leading voices in purple frog conservation, attended a training in Madagascar after receiving the Edge fellowship from the Zoological Society of London. One of the talks in the programme was led by Dr Patricia Wright, an American primatologist and one of the prominent figures in the conservation of Lemurs in the island country.

Patricia stressed the importance of connecting the species that you want to conserve with the local community and its culture, Sandeep recollected. "Throughout the lecture, I was thinking, this bizarre-looking, or in some people's words, an ugly-looking frog, how will I make a connection. And then, suddenly, it struck me, why can't I use this one day emerging behaviour and connect it with the Mahabali story? And that's how we came up with the 'Mahabali frog' name," Sandeep said.

And so, during the Onam season of 2017, Sandeep and his team launched an intensive campaign to raise awareness and support for the conservation of the Mahabali frog. They wrote extensively in the media, created social media content, and even featured in various nature magazines. "That strategy worked well," Sandeep said. "People started recognising the species whenever we attended events or programmes. Connecting it with Mahabali made it familiar. Instead of talking about it as a ‘living fossil’ or explaining its link to the Gondwana theory, this cultural reference clicked with people."

Living fossil
The Mahabali frogs have a long evolutionary history. They are believed to have existed on the planet for around 60-90 million years and could possibly have shared the earth with dinosaurs at some point in time, Sandeep said.

Their only known relatives are found in the islands of Seychelles, near the coast of East Africa. This curious connection has given weight to the Gondwana land theory—the idea that India, Africa, South America, Antarctica, and Australia (i.e., present-day continents of the Southern Hemisphere) were once part of a single supercontinent called Gondwana.

"Amphibians can't tolerate salt water, so the idea that they swam across the sea was ruled out. When India drifted away from the rest of the landmass, this species likely became isolated here. That supports the Gondwana land hypothesis, back when everything was one," Sandeep explained. He added that their genetic relationship with the frogs in Seychelles and their long evolutionary history make them a living fossil.

A monsoon indicator
Not much is known about the lifestyle and habits of Mahabali frogs. They spend most of their lives in deep underground burrows, and that hidden phase of their existence is still largely a mystery, Sandeep said.

However, they emerge from their subterranean homes just once a year to breed. This rare emergence takes place just ahead of the first monsoon rains. The frogs carefully time their egg-laying with the onset of the rains, ensuring that the breeding sites get flooded during the heavy downpours of the monsoon season.

"It's still a mystery how the frogs, which spend almost their entire life underground, know exactly when the rain is about to begin. They may have some internal blueprint of the seasons. The mating calls of the Mahabali frogs can be heard during the first rains, and that's the perfect time to observe them," Sandeep said.

The purple frog remains above ground for just two to three hours. "The males, which are only about half the size of the bloated females, call out to attract mates. They climb onto the backs of the females, who carry them to suitable egg-laying sites," Sandeep said. "However, predators wait above ground, even for the short time the frogs are active. Brown fish-owls, checkered keelbacks, and other predators often prey on them," he added.

Victim of climate change?
The greatest threat to the Mahabali frog comes not from predators, but from human-induced climate change gripping the planet and habitat loss. In Kerala, shifting weather patterns have thrown seasonal rhythms into disarray— monsoons arrive early or are delayed, and summer rains come in unexpected bursts followed by long, dry pauses.

"These changes disrupt the breeding cycles of the Mahabali frog," says Sandeep. "They lay their eggs along streams and in running water. If there's no water when they breed, the chances of the eggs hatching are very low."

In addition to climate-related disruptions, habitat loss is another major threat to the species. "It’s believed that only about half of the Mahabali frog population is found within protected areas. The rest are scattered across the hill ranges of Kerala, where they face greater risks," he added. Another major threat to them is road kills and illegal mining along their habitats.