The onset of the monsoon in Maharashtra’s Sahyadris brings the kind of relief, romance and frenzied activity that one hardly imagines is present in the hills and countryside. This passion is not restricted to us humans, with a wanderlust for drives, cycle rides, nature walks and hikes in the mist and downpour. I know the monsoon is about to arrive when I hear the excited calls of the lovely whistling schoolboy (Malabar whistling thrush, or Myophonus horsfieldii) seeking a partner and announcing the impending rain. At the onset of the monsoon and rolling thunderstorms, we see glowing fireflies flashing an amorous glow to attract a mate, and the shrill yet happy symphony of different tree frogs brings the night alive. However, the real scene-stealer is the Indian bullfrog, with its adrenaline rush and pumped-up testosterone levels.

In June 2021, just when the monsoon had started, I was enjoying an early morning ramble with my three dogs in Lonavala when I heard what sounded like a JCB working on a construction site. Two of my dogs immediately jumped on to a wall to check out the source of the sound, so I peeked over to figure out what was causing the thundering cacophony.

I was awestruck. The shallow marsh on the other side of the wall was a sea of jumping, croaking copulating bullfrogs. Some were single but most were in pairs, one atop the other. In several cases, there were threesomes—two males on a female, with the topmost one trying to dislodge his competitor and gain access to the female. The yellow-jacketed riders (males), their bright blue vocal sacs inflating and deflating, were croaking high-decibel love ballads in a desperate attempt to woo the females.

In the breeding season, the males change colour from olive green and brown to bright yellow. They are also smaller than the females. I guess that’s what allows the female to leap and jump around as her suitor clings to her back and fertilises the eggs as she releases them. In the past, I had seen several dozen Indian bullfrogs mating in ponds in the Sahyadris but the sound of hundreds of them calling out competitively together, and the sight of so many rapt in the throes of intimacy, was unforgettable.

A breeding male in all his yellow splendour, his inflated blue vocal sacs let out deep, resonant calls to potential mates.
(Wikimedia Commons/Danielnasika1, CC BY-SA 4.0)

Frog legs—a delicacy

My earliest encounter with the Indian bullfrog goes back to when I was a teenager; the frog was called Rana tigerina. I had take a local train to the Kamshet railway station, then a quaint, quiet stop just outside Lonavala, a starting point for many enjoyable hikes into the surrounding hills and fields. The monsoon rains made these walks all the more attractive. On one rather wet and rainy day, I was waiting at the station for the train and noticed several gunny sacks on the platform that kept jiggling and moving. With no one around and my curiosity aroused, I tried to poke and prod the sack with a small stick. Just then, the station master came around and told me not to disturb the sacks. “What’s inside?” I asked in Marathi. “Mendak,” he replied, and, seeing my confused look, said, “bullfrog”. He explained that they were destined for Mumbai and export as their legs were considered a delicacy in fancy restaurants and fetched a good price. After some friendly conversation and a little cajoling (and telling him that my dad had been a railwayman, too), he got one of the staff to open a sack so I could look in. There must have been 70-80 large frogs inside and it seemed crazy that they were being transported like that. Of course, this was well before I had heard of the exotic meat trade and prior to the ban on the consumption or export of frogs (implemented by the Union government in the mid-late 1980s).

Since then, Rana tigerina has been reclassified and given the scientific name Hoplobatrachus tigerinus. At 12-20cm in length, it is India’s largest frog species. Owing to its solitary nocturnal nature, it is relatively unknown, rarely seen outside the breeding period. Indian bullfrogs stay hidden in and around wetlands, freshwater areas and fields, which has led people to believe they hibernate underground, emerging only for a day or two during the mating season. This is not true.

I have often heard people say they fear the Indian bullfrog during its mating season because they think the bright yellow colour of the males is toxic. This too is untrue, for they are not poisonous or toxic—as we know, humans have long enjoyed eating Indian bullfrog legs.

After the first monsoon rains in the Western Ghats, Indian bullfrogs gather at temporary pools and other waterbodies for a few days of noisy, frenzied mating.
(Wikimedia Commons)

Breeding avatar

When the monsoon starts, the males of the species transform. They change the colour of their suit to an attractive and vibrant yellow. Showing off their navy-blue vocal sacs (which inflate and deflate rhythmically), they croak loudly, incessantly during the short mating season. The females remain olive-green-brown, with dark patches. Eggs hatch in less than a week, while tadpoles take one-three years to become fully grown adults with a lifespan of 7-10 years.

Bullfrogs have an insatiable appetite and will wolf down almost anything—insects, larvae, lizards, smaller frogs, even small snakes and birds. They will lie in wait, motionless and well camouflaged, then leap with open mouths to ambush and grab their prey and swallow it whole. You can sometimes see a large insect struggling inside, against the skin of the stomach, till lack of air, stomach acids and enzymes seal its fate. Indian bullfrog tadpoles are carnivorous creatures that will eat tadpoles of other frogs—and their own species.

The Indian bullfrog’s colour varies from brown to olive green and dark yellow. Females are larger than males and do not change colour.
(Seshadri KS)

Monsoon romance

When it comes to monsoon romance, few can beat the Indian bullfrog. In the Western Ghats, I have seen them emerge a day after the monsoon rains arrive and congregate at pools. The honeymoon, relatively short-lived, begins. After two days of noisy romping, incessant croaking and fornicating for hours, the bullfrogs disappear, with not a trace of their merrymaking anywhere, except perhaps in the unseen fertilised eggs in the water bodies.

The morning after my encounter with hundreds of Indian bullfrogs in the bog, my dogs and I spent several minutes searching for any signs of those leaping, bobbing yellow amphibians. Not one was in sight. Bullfrogs, however, are prolific breeders and a single clutch of eggs can contain over 5,000 eggs scattered around, ready to hatch in under a week.

I know that come June, I must keep an ear out for the carnival—it will be back in town, same time, same place, every year.

Andre Morris runs an outdoor adventure and education company, happily spending both his work life and leisure time in forests and mountains. He wrote this piece for RoundGlass Sustain, a not-for-profit telling stories of India’s natural world to create awareness and support conservation.

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