Innate and Learned Predator Recognition Mediated by Chemical Signals in Eurycea nana

Abstract

Effective and efficient predator recognition and avoidance are essential for the persistence of prey populations, especially in habitats where non‐native predators have been introduced. Predator recognition studies are commonly couched within a learned or innate dichotomous framework; however, characteristics of some systems or species could favor innate recognition combined with the ability to alter avoidance responses based on experience with predators. Eurycea nana is a fully aquatic salamander inhabiting a system with a diverse, yet temporally stable, community of native and non‐native opportunistically foraging fish predators. To examine predator recognition, we examined avoidance responses (decreased activity) of predator‐naïve (first‐generation, captive‐reared) and predator‐experienced (recently collected) E. nana to the chemical cues of a native predator, a non‐native predator, a non‐predator, and a blank control. Both predator‐naïve and predator‐experienced E. nana significantly lowered activity in response to the native fish predator when compared with a blank control. Interestingly, predator‐naïve E. nana decreased activity in response to the non‐native fish predator while predator‐experienced E. nana did not. These results indicate that while there is an innate component to predator recognition in E. nana, experience and risk assessment may also be important.

Training for Translocation: Predator Conditioning Induces Behavioral Plasticity and Physiological Changes in Captive Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis) (Cryptobranchidae, Amphibia)

“…These results substantiate other work that found that amphibians, including hellbenders, have innate behavioral responses to predator kairomones [32,59,60]. Crane and Mathis [11] found that larval hellbenders, 21-25 weeks old, increase their swimming when exposed to trout kairomones, which they interpreted as evidence of escape behavior.…”

Fear is the mother of invention: anuran embryos exposed to predator cues alter life-history traits, post-hatching behaviour, and neuronal activity patterns

“…The contextual behavioural response of agile frog larvae to dragonfly kairomone might thus be, to a large extent, innate (Lima and Dill, 1990;Scheurer et al, 2007;Epp and Gabor, 2008), as control tadpoles displayed the typical anti-predator behaviour upon their first postnatal experience with the odour of the predator (Fig. 2C,D).…”

Amphibians breeding in refuge habitats have larvae with stronger antipredator responses

“…These tests allowed us also to determine the effect of the site of origin (surface streams versus cave) and rearing conditions (predator and predator-free environments). Predator cues were obtained by maintaining six C. bidentata larvae for 24 h in 1.5 litres of dechlorinated tap water; the water was aliquoted (1 ml) and immediately stored at À20 C until use for behavioural tests, following the procedure of Epp and Gabor (2008). As control cues, we used 1 ml of tap water.…”