Cane Toads: Prolific Invaders

Cane Toads: Prolific Invaders

When it comes to stories of human-propelled environmental disasters, the Cane toad’s tale can be found near the top of the list.  A native species to Central and South America, the Cane toad was first introduced to the islands of the Pacific in the early 1900s, hoping to be used as a form of “pest control.”  At the time, sugar cane fields were being attacked by the pesky Cane beetle, which were successfully destroying this staple crop of the islands.  The thought was to set the Cane toads loose amongst the fields in hopes of exterminating the Cane beetle.  The first experiment occurred in Hawaii, and the results looked promising.  In 1935, Hawaii shipped a collection of Cane toads to Australia, where they too were having difficulties ridding their fields of the Cane beetle.  After seeing the successful use of the Cane toad in the Hawaiian islands, no one was quite prepared for the disaster Australia would experience.  Not only did the Cane beetles still prevail, but the Cane toads reproduced rapidly in number and have now become an invasive species of their own.

The number of Cane toads now inhabiting Australia has risen into the millions, much thanks to the record levels of reproduction.  Females can lay 33,000 eggs per spawning period, and with its lack of natural predators, the Cane toads have taken over major sections of land.  Adult Cane toads are generally quite large, some weighing in around 3-4 pounds! The toads also secret a milky toxin through their skin, making them poisonous to most predators.  Unfortunately, this venom is responsible for the deaths of many native species who have come into contact with the toads.

The photo above was taken at the Lyon Arboretum in Manoa, Hawaii, on the island where the Cane toad experiment first began.  Though Hawaii has not been affected as badly as the situation in Australia, these toads are still considered a pest to the environment, and the Lyon Arboretum is doing all that they can to keep the numbers of Cane toads to a minimum.

About this Photograph
Photograph of Cane Toads © 2011 Leigh Anne Crocco.