The Asian or Black-spined Toad (Duttaphrynus melanostictus) has all the makings of a classic bad guy. Considered one of the most successful amphibians at wreaking havoc in habitat where it doesn’t belong, this invasive species is best known for causing severe ecological issues in Australia. The toad poisons predators, competes with burrow-nesting birds, and disrupts both nutrient pools and parasite dynamics. The Asian Toad’s latest target? Madagascar, where native species may be threatened by predation, competition for resources, or the toad’s natural defensive toxins.
Much like its distant relative, the Cane Toad (Duttaphrynus melanostictus) is highly fecund, producing up to 40,000 eggs per clutch. It is poisonous, has a generalist diet and is well adapted for life in agricultural and urban areas. Recent surveys highlight that the first records of Cane Toad in the port city of Toamasina date back to 2010. Many shipping containers, goods and vehicles arrive in Toamasina daily from abroad, although researchers aren’t sure exactly how the toad originally made its way into the country.
Unfortunately the Asian Toad could rapidly spread throughout the island, entering the residual rainforests of Madagascar, areas of unique biodiversity and endemism. Not far from Toamasina is Betampona Nature Reserve, the last remaining fragment of low-altitude rainforest in the area, which harbors an exceptionally high number of endemic amphibians, many of which have yet to be described (about one third of the species of amphibians found there appear to be novel and in need of description).
Malagasy authorities have identified Christian Randrianantoandro (from the Amphibian Specialist Group) as the national coordinator to address this new threat. A group of national and international experts on amphibians and invasive species is working together with Randrianantoandro to assess the chances of successfully eradicating the toad. As a first step in coordinating the effort, the team has been divided into small working groups to deal with different aspects of the project:
- The Survey, Education & Prevention Working Group is currently conducting delimitation surveys in order to identify the extent of occurrence of this toad. It is also preparing educational materials to inform local people of the threats posed by this toad to both humans and animals.
- The Feasibility Study Working Group is coordinated by an invasive-species expert who has identified professionals who can draft a feasibility study on eradicating the toad.
- The Chytrid & Sample Analysis Working Group carries out phylogeographical analyses to identify the source of introduction, and to screen the collected material for the presence of various infectious diseases.
- The Fundraising Working Group is working to raise funds to meet these goals.
- The Communication Working Group is responsible for maintaining active communications between the different working groups and the Malagasy authorities.
Asian or Black-spined Toad (Duttaphrynus melanostictus)