In-situ severe breeding habitat intervention only achieves temporary success in reducing Batrachochytrium dendrobatidis infection

Abstract

Chytridiomycosis, an emerging infectious disease caused by the fungus Batrachochytrium dendrobatidis (Bd), is causing sharp declines in amphibian populations around the globe. A substantial research effort has been made to study the disease, including treatments against Bd, but most treatments have been applied to captive amphibians only. We report a study aimed at clearing wild populations of the Common Midwife toad Alytes obstetricans. We removed all larvae from natural breeding sites (cattle troughs) and conducted two types of severe breeding habitat manipulation (complete drying and fencing for the whole breeding season). While larval removal followed by drying was a successful method of Bd elimination, the effect was only temporary. Since terrestrial habits of adult A. obstetricans prevent them from infection, our findings suggest that, even in simple breeding habitats where all aquatic amphibian stages can be handled and extreme habitat intervention is possible, Bd cannot be eliminated without controlling other potential Bd reservoirs in the surroundings of breeding sites.