The new toad in town: Distribution of the Asian toad, Duttaphrynus melanostictus, in the Toamasina area of eastern Madagascar

Abstract

In March 2014, the Asian toad Duttaphrynus melanostictus was reported from Madagascar’s second largest city and main port Toamasina, raising immediate concerns about the invasive nature of the newly introduced toad and its environmental impact should it spread throughout the island. As part of a study on the feasibility of eradication, we conducted 516 interviews and 120 visual encounter surveys between April and November 2014. We found the toad to be widespre ad to the south and west of city center and estimate its minimum range to include an area of at least 108 km 2 . Social surveys indicate that the toad may have already been present for some years and potentially introduced prior to 2010, with the site of its introduction likely south of Toamasina near National Route 2 and the Ambatovy Plant. We discuss limitations of our survey methodology, proposed improvements for future work, and the implications of our results on eradication and control measures.