Effects of hunger and predation risk on foraging behavior of graybelly salamanders, Eurycea multiplicata

We examined the effects of predation and hunger levels on fr,raging behavio r of adult neotenic graybelly salamanders, Eurycea multiplicata griseogaste r. Hungry and satiated salamanders were exposed to chemical stimuli from a predatory fish (sculpin, Cottus carolinae) and from two nonpredatory specie s, golden redhorse fish (Moxostoma erythrurum) and tadpoles of leopard frog s (Rana sphenocephala). Latency to attack prey was lengthened in the presen ce of chemical stimuli from predators regardless of hunger levels, but hung ry salamanders had shorter latency times than satiated salamanders. There w as no interaction between hunger and threat levels. In addition, salamander s distinguished between chemical stimuli from predatory (sculpin) and nonpr edatory (redhorse) fishes; responses to redhorse and tadpole stimuli were n ot different. Handling limes were not affected by either predator treatment or hunger level. In summary, graybelly salamanders can (1) recognize sculp in predators based solely on chemical cues, (2) distinguish between chemica l stimuli from predatory and nonpredatory fish, and (3) adjust their foragi ng behavior according to both hunger and predation risk.