The Sad Parable Of The Frogs of Calcutta

Over-exploitation of a species can have dire effects that reach even beyond the creature's extinction. Consider, for example, the warning implied in the harvesting of frogs from the marshes about Calcutta (now Kolkata), India. In attempting to satisfy a large demand for frogs' legs from European markets, some Indian entrepreneurs encouraged local farmers to catch as many of the amphibians as they could.

By the late 1980s, the area had become completely frogless. In the absence of their natural predators, mosquitoes flourished, as did small crabs that feast on rice plants. The pesticides needed to control these population explosions cost farmers far more than the profits gained from the sale of frogs.