The common midwife toad, Alytes obstetricans, is able to learn a simple task under an appetitive stimulus

Abstract

Studies of response learning of amphibians are scarce compared to other vertebrates. We conducted a simple experiment to evaluate response learning in a primitive anuran species, the common midwife toad (Alytes obstetricans) under an appetitive stimulus. We hypothesized that, despite the primitive character of the studied species, the animals would be able to rapidly associate a particular arm of a basic T-shaped experimental arena with the reward, and that the existing male parental care of the species would provide males greater cognitive abilities than females. The response obtained by 12 males and 13 females was statistically different than such expected by chance, suggesting a learning process. The sex of the animal, as well as the average time spent to select the correct choice, were key during the learning process. Contrary to expectations, females showed higher learning capacities than males, perhaps as a consequence of the elaborate mate selection process and the competition between females to access males in this group of amphibians. The obtained results indicate that a rapid learning capacity is highly conservative in the phylogeny, having evolved from early tetrapods to those existing today in reptiles, birds, and mammals.