For those of us who are fortunate enough to live close to the ever-disappearing lakes of Bangalore, the onset of the rains bring with it a special chorus sung during the night. I am sure everyone is familiar with it. It seems that the perpetuators of this chorus are as joyous as we are for the arrival of life-giving rain. Each new shower of rain is welcomed with a fresh bout of calling. The unseen voice is that of the Indian Bull Frog.
The Indian Bull Frog (Hoplobatrachus tigerinus) is the largest of the frogs found in India. It is found all over the Indian subcontinent and is an integral part of the ecosystem of any pond, well or field. We usually tend to miss seeing them as they blend so well with their habitat.
The term ‘Bull Frog’ refers to a number of large, aggressive types of frogs found all over the world. They are not all related, and live in very different habitats. Bull frogs do share some common behavioral traits and eat a fairly similar diet, especially in captivity. As a group, these frogs tend to be voracious carnivores, eating nearly anything they can catch.
Look carefully at the grass near the edge of any bit of permanent or semi-permanent body of water and you are sure to find them lurking there. But be quick for they have a tendency to jump into the water at the smallest sign of danger.
The Indian Bull Frog, though vocal during the rains, which happens to be their breeding season, is silent during the rest of the year. During the dry season, when there is no permanent water, they estivate which is similar to hibernation but occurs during the summer. In places where the soil is sandy they follow the water table as it recedes sometimes, burrowing up to a depth of eight meters.
The Indian Bull Frog, once very common, is now facing an unprecedented danger to its survival. And one of the culprits, you will be surprised to learn, is our taste buds. Yes, the Indian Bull Frog is selectively poached for its large fleshy legs, the most prized part of a frog. I use the word ‘poached’ and not ‘killed’ because in 1985, the Government of India declared a blanket ban on the catching and the killing of frogs under the Wildlife (Protection) Act 1972.
– Largest of frogs found in India- Usually solitary and nocturnal
– Females are larger than males (about six inches in size)
– Breed during the rainy season, the only period when they croak
– Males have external vocal sacs which turn bright blue during the breeding season
– In dry season, they estivate, which is similar to hibernation
– Feed on insects, shrews, smaller frogs, mice, small birds, etc
– Tadpoles feed on mosquito larvae
The poaching of frogs attracts stringent punishment with a fine of Rs 25,000 and/or imprisonment up to three years. As a matter of fact, in the year 2008, ten people were detained and fined under the Act. The other dangers are habitat loss, habitat alteration and usage of pesticide. Due to haphazard ‘development’ of the lakes and water bodies in Bangalore, vital breeding areas have reduced and little space is left for this amphibian species to breed and sustain healthy populations.
It is ironical that the monsoon which is a season of vibrant life and joy for most species including frogs has now turned into the time when they are systematically hunted for food. As mentioned this is also their breeding season and the selective killing of the mature bigger adult frogs, before they breed, will lead to a catastrophic decline, drastically reducing their numbers in the future.
The Indian Bull Frogs feed on anything that moves and can be swallowed. They even use their hands to shove in parts of their prey. Apart from their normal diet of insects, they are reported to take mice, shrews, small birds, small snakes, toads and other frogs. From its diet one can gauge the role it plays in maintaining the ecological balance in its ecosystem, urban, rural or wild.
From a human and urban perspective the most important fact is that the tadpoles of the Indian Bull Frog feed on mosquito larvae, thus controlling their numbers and thereby preventing diseases and helping to save human lives. A drastic drop in their population can cause untold misery for us.
Don’t be surprised if during the middle of a chorus, one rainy night, you hear a human scream. For that is the call a Bullfrog makes when it is caught by a predator. The main predator in its case being man.