No amphibian chytrid fungus Batrachochytrium dendrobatidis detected in four introduced populations of the midwife toad Alytes obstetricans in eastern England

The amphibian chytrid fungus Batrachochytrium dendrobatidis threatens amphibian species globally as the causative agent of chytridiomycosis, with the introduction of non-native species being one of the pathways that the pathogen can spread to naive populations. We have monitored and screened the common midwife toad Alytes obstetricans in four separate populations in eastern England, to investigate the potential threats to local amphibians. Forty-eight toads across all life stages were swabbed between May 2018 and August 2020, and screened for the presence of B. dendrobatidis DNA using qPCR. None of the samples tested were positive, indicating that it is unlikely that any of the A. obstetricans swabbed were infected with B. dendrobatidis. The populations surveyed represent only a small part of the species range in Britain, consequently a more widespread survey is recommended to increase confidence that British A. obstetricans are free of B. dendrobatidis.