Name: Rhinella marina
Native Range: Central and South America
Introduction: Cane toads were intentionally introduced in Australia in 1935 to help combat cane beetles that were wreaking havoc on sugar cane crops. Their hardy nature and voracious appetite, initially an attractive quality to farmers, led them to become prolific invaders. They completely failed at regulating the cane beetles, and instead turned their attention to other native insects. Since the initial release of 3,000 toads, cane toad populations in Australia number in the millions and their range continues to expand. In addition to Australia, they’re found in south Florida, throughout the Caribbean, and in other tropical and subtropical locales.
Why are they harmful?: Cane toads will eat just about anything they can fit into their mouths, including a wide range of native insects. This reduces prey for native insectivores and creates stress within the ecosystem.
Cane toads are also poisonous throughout their lifecycle. Whether they’re eggs, tadpoles, or full-grown adults, cane toads can poison and potentially kill anything that ingests then. Unfortunately, this also includes curious household pets that lick or bite them. Cane toad poisoning in dogs in Australia has become quite common, and can kill the animal. In Hawaii, up to 50 dogs a year die from cane toad poisoning. People aren’t safe either — people have died after eating cane toads or even consuming soup made from boiled cane toad eggs.
Methods of control: Currently, manual removal is the main management strategy for cane toads. Although toads can be removed as adults, it’s easiest to collect the jelly-like strings of cane toad eggs from local creeks or ponds. Also, mesh fencing is used to stop the spread of the toad, but native fauna can also get caught up in the nets. In Australia especially, there is a widespread education campaign to warn people about the dangers of cane toads and invasive species.
Photo credit (cover photo): Pete Hill