THE ONTOGENY OF CHEMICALLY-MEDIATED ANTIPREDATOR BEHAVIOURS IN NEWTS (NOTOPHTHALMUS VIRIDESCENS): RESPONSES TO INJURED AND NON-INJURED CONSPECIFICS

Jason Rohr, Dale Madison, Aaron Sullivan
2002 Behaviour  
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
more » ... paring 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 conspeci 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 1) Corresponding author's present address: 101 Morgan Building, Also available online -1044 ROHR, MADISON & SULLIVAN to adult rinses and extracts. There was no difference between responses of recently hatched naïve and experienced larvae, indicating that larvae exhibit innate antipredator behaviors in response to adult odour. Adults were indifferent to all larval treatments and adult rinse, but avoided adult extract. Since neither adults nor larvae responded to larval extract, larvae did not appear to possess alarm chemicals, and consequently, we were unable to assess the in uence of experience on alarm substance response in larvae. Adults and efts were indifferent to rinses, but avoided extracts from conspeci cs of both life-history stages. Together, these results demonstrate that red-spotted newts do not produce alarm chemicals until late in larval development, but can respond to predation-related chemical cues soon after hatching.
doi:10.1163/15685390260337895 fatcat:2s2brbbaprfoxavub4aetvrng4