PS 32-114
Inferring differential survival of two color morphs of the red-backed salamander, Plethodon cinereus
Color polymorphism is common in many species and morph frequency is often affected by differences in ecological and evolutionary pressures on each morph. Plethodon cinereus, the red-backed salamander, has two common color morphs, striped and unstriped, that vary in frequency among populations. There is evidence that the unstriped morph has higher tail autotomization rates which may be resultant from differential predation. Additionally, each color morph has been shown to have different escape behaviors when exposed to predators. We tested the hypothesis that differential predation of the striped and unstriped color morphs occurs in Plethodon cinereus. We determined the effect of color on survival of P. cinereus using three years of mark-recapture data. We also used clay models to test for potential differences of attack by two types of predators, birds and mammals, on replicas of the striped and unstriped morphs.
Results/Conclusions
We found that the frequency of striped salamanders drastically changed between juveniles and adults, with lower frequencies of striped adults. We also found that there was greater predation on the striped clay model morph by avian predators compared to the unstriped models, but there was no difference in predation by mammals. Overall, these results support the hypothesis that there is differential predation in Plethodon cinereus, with lower survival in the striped morph. Future studies should investigate avian predators and their effects on morph frequencies on different populations of P. cinereus.