Meeting Abstract
117.7 Tuesday, Jan. 7 11:45 Coevolution of Coloration and Conspicuousness in a Batesian Mimic KRAEMER, A. C.*; SERB, J. M.; ADAMS, D. C.; Iowa State University; Iowa State University; Iowa State University kraemer1@iastate.edu
In Batesian mimicry a palatable mimic deceives predators by imitating the appearance of an unpalatable model. Two hypotheses have been proposed to describe how selection from predators influences the evolution of warning signals in models and mimics. First, predators are thought to drive mimic coloration to converge on models while selecting models to appear distinct from mimics. Second, predators are thought to select for conspicuousness in models and inconspicuousness in mimics, and furthermore, models will evolve towards higher conspicuousness when mimics are present to appear distinct from mimics. To test these hypotheses we used a Batesian mimicry system between two salamanders: the model species Notophthalmus viridescens, and a mimic, Plethodon cinereus. We compared salamander color and conspicuousness by projecting their reflectance spectra into the visual spaces of three predators. We found that mimics and models were indistinguishable from the perspective of all three predators. Second, model coloration was found to be most conspicuous, and mimic coloration least conspicuous, against backgrounds that predators most likely view salamanders. Third, model and mimic conspicuousness co-varied among sites where they co-occurred. Finally, we found models were most conspicuous at sites where mimics occurred. These findings indicate that mimic coloration has converged on the coloration of models while appearing relatively inconspicuous to predators, particularly against likely backgrounds. Our findings also show that models have evolved to be most conspicuous against likely backgrounds, especially in the presence of mimics. These results suggest that not only does selection for mimicry drive mimic phenotypes towards models, but may also drive up model conspicuous keep predators from confusing them with mimics.
