The cane toad (Bufo marinus) is a toad native to South and Central America. The toads were deliberately introduced into nations all over the world as a form of insect control, much to the later regret of many of those nations. The toxic animals are largely regarded as pests, even in their native territory, and in some places they have infiltrated popular culture. Australia's battle with the cane toad has drawn global attention.
The skin of a cane toad is dry and warty, with a yellowish to brown color and dark spots on a creamy belly. The toads average around four to six inches (10-15 centimeters) in length at adulthood, although significantly larger specimens have been recorded. The poison, bufotoxin, is held in glands which run down the back of the cane toad, starting behind the eyes. When stressed, the cane toad secretes toxin.
The common name for the toad comes from the mistaken idea that it could be used to eradicate the beetles which infest sugar cane. As it turns out, since the cane toad cannot jump very high, it is unable to scale sugar cane to reach cane beetles. However, cane toads will eat everything else, living or dead, and this is one of the reasons they are classified as an invasive species. While most cane toads eat primarily insects, they have also been known to eat everything from dog food to small mammals.
The poison also makes cane toads an issue in areas where they are introduced. Native species have no natural immunities to the poison, resulting in death by cane toad for many predator species which attempt to eat the animals. Since the tadpoles are toxic as well, this has an impact on multiple levels of the food chain. Household pets have also been known to die as a result of cane toad encounters, and humans can become seriously ill.
Unfortunately for nations struggling with the toxic toad, cane toads reproduce astoundingly well. A female cane toad can lay up to 33,000 eggs at one time, in long stringy clumps. Despite the best efforts of governments trying to eradicate the cane toad, the animals keep spreading, often attaining a dominant ecological niche because of their bufotoxin. In Australia, the animal is viewed as an ecological disaster, and the story of the cane toad is told around the world in science classes to explain why introductions of non-native species are potentially very dangerous.