Monsoon Magic: A Nighttime Trek To See Goa's Glowing Forests

A hike in a wet leech-infested wilderness after a sumptuous dinner would not appeal to most people on a holiday. However, an invitation to see something extraordinary at night can push anyone with even a faint interest into discovering the wonders of the natural world.

A few years ago, Nirmal Kulkarni, the well-known herpetologist and Goa-based wildlife conservationist, took me on a night trail through Chorla Ghat, Goa—a section of the Western Ghats in the Sahyadri mountain range. The monsoon had been bountiful that year, making the dense forest resplendent with hues of green. With just the aid of a torch beam, we scrambled up a slippery slope with only frog calls for company. After a short hike we came to an abrupt halt in the middle of nowhere. We promptly switched off the torch lights to immerse ourselves in pitch darkness, and suspense followed. Once our eyes got adjusted to the deep, dark forest, it began to reveal its secrets.

First, on the left, we saw a faint glow of "fluorescent" green coming onto a portion of a dangling branch. It slowly began to spread and intensify, although unevenly, and some even faded away. Similar glowing patches appeared on the right and the forest floor ahead. At a distance, a tree trunk glowed in a similar fashion. Soon, we were surrounded and captivated by the mesmerising display of light and sound. These were not fireflies or glow worms (also present in this landscape) but bioluminescence fungi and mushrooms that occur only during the monsoon season. Unlike what I initially thought, bioluminescence is not the same as fluorescence.

While fluorescence does not involve a chemical reaction, most bioluminescence is a chemical reaction involving luciferin, the light-producing compound, and luciferase, an enzyme. The phenomenon of bioluminescence requires a certain threshold of rain and moisture for these organisms to flourish on the forest floor. The glow increases or decreases depending on the pattern and consistency of the monsoon rain. The monsoon forecast looks good this year, with predictions of above-average rain due to the La Niña phenomenon in the Pacific Ocean. But with the ongoing climate crisis and changing rainfall patterns, it's hard to predict what the future holds for this nature's spectacle. While we know that living organisms use bioluminescence for hunting, defending against predators, or finding partners to procreate, we do not fully know the exact conditions and nature of the glow, or even the ecological role they play in the complex scheme of nature.

These days, a fair number of people travel to Goa during the monsoon season but very few get out from the pull of the beachside to explore Goa's fascinating natural history. Goa's eastern side, around 600 sq. km of the biodiverse Western Ghats, is worth exploring—from Mhadei Wildlife Sanctuary to the Cotigao Wildlife Sanctuary. Once the showers drench the mountains, the emerald forest comes alive with bird and frog-toad song, endemic species of orchids and carnivorous flowering plants of the coastal laterite plateaus, psychedelic crabs, and jaw-dropping waterfalls. Interestingly, several new species have been discovered (and rediscovered) from this part of the state.

However, despite the rich biodiverse treasures, Goa never got a place on the wildlife destination map. But change is not far, with more and more people getting a taste of the adventure that Goa's wild has to offer.

Ananda Banerjee is an author, artist, and wildlife conservationist