Predators influence the evolution of color pattern in prey species, yet how these selective forces might differ among predators is rarely considered. In particular, prey color patterns that indicate unpalatability to some predator species may not carry the same signal for other predators. We test several hypotheses of selection on patterning between mammal predators and the polymorphic salamander Plethodon cinereus, which, under an avian visual system appears as a mimic of the toxic newt Notophthalmus viridescens. We fit each hypothesis against field observations of mammalian attacks on salamander clay replicas. We then develop a novel analytical procedure that enables the combination of multiple non-exclusive models in a likelihood framework. We find that mammals do not follow any single hypothesis proposed, including the hypothesis of mimicry. Instead, mammals in this system use visual cues while foraging to avoid unfamiliar, novel prey and attack conspicuous prey. We propose that mammals may help to maintain color pattern polymorphism within populations of P. cinereus by avoiding novel, unfamiliar color morphs. Additionally, selective pressures from multiple predators and variation in predator communities among sites may contribute to the maintenance of color polymorphism within and among localities in this salamander species.
Available at: http://works.bepress.com/jeanne_serb/15/