Behavioural responses to chemical cues of predators differ between fire salamander larvae from two different habitats

Prey organisms need to detect predators and respond with adequate antipredator behaviours. To recognize predators, chemosensory cues play a pivotal role, particularly in aquatic ecosystems, where sight may be restricted. However, it is less known whether the ability to use these cues, enabling appropriate antipredator behaviour, varies between subpopulations occupying different habitats with different predation risks. We examined antipredator behaviour of wild-caught larval fire salamanders (Salamandra salamandra) from two different habitats, ponds and streams. Ponds and streams are inhabited by habitat-specific predators, such as alpine newts (Ichthyosaura alpestris), which only occur in ponds. We confronted larvae from both habitats with either tap water (control) or tap water that had contained alpine newts (newt treatment) and investigated potential behavioural differences in activity and shelter emergence. In the activity test, pond larvae, but not stream larvae, were significantly less active when faced with chemical cues (potentially kairomones) from newts than those faced with a control stimulus, but stream larvae generally exhibited significantly lower activity than pond larvae. In the shelter-emergence test, larvae from both habitats spent significantly less time outside a shelter in the newt treatment than in control water. This suggests that larval fire salamanders, independent of their habitat, recognize chemical cues from potential predators and alter their behaviour accordingly. Larvae of both habitats were able to detect and use chemical cues released from potential predators, but they differed slightly in their response to these chemical cues. This finding reflects varying antipredator strategies in response to the habitat-specific differences.

Automated summary

The study found that larval fire salamanders from different habitats are able to recognize chemical signals from potential predators and adjust their behavior accordingly. However, there were slight differences in their response to these chemical cues, reflecting varying antipredator strategies in response to habitat-specific differences.