INDIAN BULLFROGS TAKE TO INVASIVE BEHAVIOUR EARLY IN ANDAMANS
22, Apr 2019
Prelims level : Environment, Bio Diversity Mains level : Environmental Conservation
Why in news:
- Indian bullfrogs introduced in the Andaman Islands are invasive, and eat native wildlife including fish and lizards. Experiments reveal that bullfrog tadpoles ate up all tadpoles of two endemic frogs
- The Indian bullfrog Hoplobatrachus tigerinus (native to the Indian subcontinent) has rapidly invaded the Andaman Islands after it was introduced there in the early 2000s. In human- dominated areas, it now shares space with other native frog species. The bullfrogs are prolific breeders: they have short breeding seasons, and each egg clutch can contain up to 5,750 eggs. Its tadpoles are carnivorous and eat other tadpoles (including their own species). They are along with native endemic frogs Microhyla chakrapanii and Kaloula ghoshi. Individuals of the endemic frog tadpoles in most pools were eaten by bullfrog tadpoles within the first week itself. Bullfrogs are found all over mainland India, but it is in the unique ecosystem of the islands that it becomes a major threat. Asia bullfrog, is a large species of frog found in mainland Myanmar, Bangladesh, India, Pakistan, Afghanistan, and Nepal. It has been introduced in Madagascar and India’s Andaman Islands where it is now a widespread invasive species.
- They prefer freshwater wetlands and aquatic habitats. Generally they avoid coastal and forest areas.
- Resources on the islands are scarce for big animals, while natural calamities are more frequent. The wildlife here has evolved in a miniature setting: there are no large herbivores (the largest is the Andaman wild pig) or large carnivores. Islands have fewer species, but their nature make them irreplaceable. They are found nowhere else in the world.This makes the entire food web in the islands very different from that of the mainland.