Limb malformations in introduced populations of midwife toad Alytes obstetricans in Great Britain

Amphibian limb deformities can arise from various factors, including parasitic infections, environmental pollution, ultraviolet radiation, and regeneration errors. In Britain, the prevalence of such deformities remains under-researched. The common midwife toad (Alytes obstetricans), an introduced species in Britain, has been monitored since 2015, with populations mainly confined to residential gardens. During surveys, five cases of limb malformations were recorded across three separate populations, while no deformities were observed in native amphibian species within the same habitats. Possible causes, such as agricultural pollution, ultraviolet radiation, and trematode infections, were considered unlikely, though genetic inbreeding remains a potential factor. Continued monitoring is essential to assess the frequency and causes of these abnormalities within A. obstetricans populations.