The Asian toads (Duttaphrynus melanostictus) are thought to have arrived on the African island from a container ship. The toads have also caused problems in Australia, and this problem relates to their toxicity. Any animal that eats a toad dies. Predators at risk include birds like hawks and mammals like fossa and mouse lemur.
In addition, the toads are breeding fast and out-competing many other types of wildlife. The toads also hunt down and eat frogs and chameleons. To cap all this, the toads spread amphibian diseases such as ranavirus, which can kill frogs.
Asian toads grow to about 20 centimeters (8 inches) long, with the main breeding season being during monsoons. The skin of the toad resembles a rough and warty surface. Females lay around of 20,000 eggs per year.
Authorities in Madagascar are struggling to deal with the toads, and the toads are breeding at a fast rate with an estimated 4 million toads. Efforts are focused on limiting the spread of the toads by creating protective zones. According to Science News, there is no immediate solution to deal with the toads themselves.
A new report (“Asian Toad Eradication Feasibility Report”) has outlined some possible options. These are:
Do nothing;
Protect areas currently unaffected by the toads;
Seek to eradicate the toads.
The last option – eradication – is difficult because any mechanism is likely to affect other wildlife as well.
Another risk factor is the toads spreading to other countries, probably in a similar way to how they arrived on Madagascar, which is via ships. There are concerns about Madagascar’s ability to maintain biosecurity.
The report recommends external help and funding from wealthier nations to help to preserve Madagascar’s rich diversity of wildlife and to contain the problem.
