Love is in the Air: Indian Bullfrogs and the Romance of the Monsoon

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 monsoons 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 adrenalin 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 onto a wall to check out the source of the sound, so I peeked over to figure out what was causing the thundering cacophony. Instead of a JCB, I was awestruck by the sight before me. 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 at the bottom. The yellow-jacketed riders (males), their bright blue vocal sacs inflating and deflating, were croaking away high-decibel love ballads in a desperate attempt at wooing the females. 

Interestingly, 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 onto her back and fertilises her eggs as she releases them. In the past, I’d 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.

Frog legs – a delicacy

My earliest encounter with the Indian bullfrog goes back to when I was a teenager, and the frog was called Rana tigerina. I’d take a local train to Kamshet railway station, then a quaint, quiet stop just outside Lonavala, and 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 back home 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, wondering what was inside. Just then, the stationmaster 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 Bombay and then to be exported, as their legs were 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 inside. There must have been seventy or eighty 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 Indian government in the mid to late 1980s). 

Since then, Rana tigerina has been reclassified and given the scientific name of Hoplobatrachus tigerinus. At 12-20 cm in length, it is the largest frog species found in India. Because of its solitary nocturnal nature, it is relatively unknown to most of us and rarely seen outside of 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. But this is not true; the Indian bullfrog does not hibernate or live underground.

I’ve 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. But this is also untrue, and they are not poisonous or toxic — as we know, humans have long enjoyed eating Indian bullfrog legs.

Breeding avatar

When the monsoon starts, the males of the species transform their avatars. 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 and incessantly during their short mating season. The females remain olive-green-brown with dark patches. Eggs hatch in less than a week, while tadpoles take one to three years to become fully grown adults with a lifespan of seven to ten years.

Bullfrogs have an insatiable appetite and will wolf down almost anything they get their jaws around — insects, larvae, lizards, other smaller frogs and 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 finally seal its fate. Indian bullfrog tadpoles are carnivorous little creatures that will eat tadpoles of other frogs and their own species.

Romancing in the rain

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

The morning after my encounter with hundreds of Indian bullfrogs in the bog, my dogs and I spent several minutes searching the area for any signs of those leaping, bobbing yellow amphibians, but alas, not one was in sight. But bullfrogs are prolific breeders, and a single clutch of eggs can contain over five thousand eggs scattered around, ready to hatch in under a week. So, I know, come June, I must keep an ear out for the carnival — it will be back in town, same time, same place, every year.

Photo sources: cover image, male