The Ontogeny of Chemically-mediated Antipredator Behaviours in Newts (notophthalmus Viridescens): Responses to Injured and Non-injured Conspecifics

Responses to alarm chemicals from injured prey may in uence predation risk and foraging success of receivers and senders, while learning can in uence the strength of these responses. Thus, it is important to know when in ontogeny prey produce and detect alarm substances and how learning shapes their response, but surprisingly little is known about either of these topics. We assessed when in the life of red-spotted newts, Notophthalmus viridescens, alarm chemicals are produced and detected by comparing adult versus eft (terrestrial juveniles) and larval responses to rinses and tissue extracts from individuals in each life-history stage. To evaluate the in uence of experience in larvae exposed to conspeciŽ c alarm substances and rinses from adults known to cannibalize larvae, we compared the response of naïve larvae, which had no prior experience with alarm chemicals or predators, to experienced larvae, which were likely to have experienced alarm chemicals and predators in their native pond. Larvae were indifferent to larval rinses and extracts, but reduced their activity in response