Abstract
The secretion of defensive chemicals onto the skin is a widely used mechanism for predator defence in anurans. Secretions often consist of a mixture of bioactive peptides with cytotoxic or neurotoxic effects. In New Zealand, introduced rodents have been suggested as main drivers for declines and extinctions of endemic frogs. We demonstrate the efficacy of Leiopelma pakeka secretions in deterring rats (Rattus norvegicus Long-Evans) from ingesting secretion-covered food and showed that they can successfully lyse rat erythrocytes. When offered a choice, rats displayed a significant preference for food pellets coated with water over those covered in frog secretions. Direct oral exposure to the secretions has no significant effects on water or food intake of rats. Video analysis showed no significant difference in the proportion of time rats spent grooming, rising on hind legs, motionless or investigating associated with exposure to the secretions. This study provides new insight into the defensive function of leiopelmatid skin secretions.