A toad native to Asia has been found on the east coast of Madagascar, a discovery that conservation scientists say threatens the biodiversity of the island’s unique fauna. The sightings of common Asian toads (Duttaphrynus melanostictus) close to the major shipping port of Madagascar were announced today as a comment in the journal Nature by a group of scientists including Christopher Raxworthy, a curator in the Museum’s Department of Herpetology.
“Based on the environmental damage that invasive toads have done in other parts of the world, for example its relative the cane toad in Australia, we think this situation in Madagascar is extremely serious,” said Raxworthy, who identified the invasive species. “There now is a short window of time for us to take action, before it becomes firmly and permanently established.”
Common Asian toads are large, reaching lengths of about 8 inches long, and contain a toxin in their skin that can be poisonous to snakes, birds, and other predators that might eat them. These characteristics, coupled with the toad’s ability to thrive in environments throughout Madagascar, including at high elevation; and the frog’s quick and fecund reproductive cycle (females lay thousands of eggs each year) make the invasion particularly troubling, scientists say.
In addition, the researchers point out potential human impacts include the poisoning of domestic animals like chickens, contamination of drinking water, and transmission of parasites in areas with poor sanitation.
“Without swift eradication of D. melanostictus, the ecological consequences of an invasion include poisoning and decline of vulnerable native predators (birds, mammals, reptiles), the spread of amphibian diseases, and the secondary effects of food-web disruption,” the comment in Nature states.
Surveys are being planned to identify the extent of invasion and to develop an eradication program, which would optimally start before the next rainy season in November.