Meeting Abstract

73.1  Friday, Jan. 6  Heliconius mimicry rings in a new Light SEYMOURE, Brett*; MCMILLAN, W. Owen; MCGRAW, Kevin; RUTOWSKI, Ron; Arizona State University; Smithsonian Tropical Research Institute; Arizona State University; Arizona State University

Mullerian mimicry theory states that two or more aposematic individuals (unprofitable individuals that exhibit a warning signal) will converge on a similar signal to share the costs of predator education. However, this is not the case in many organisms that should exhibit Mullerian mimicry. We tested the hypothesis that different mimicry rings (differently colored groups of aposematic individuals) have evolved due to microhabitat segregation in Heliconius butterflies. We predicted that individuals in mimicry rings would choose a light environment that confers the strongest signal. In the tropical forest there are four light environments: red, blue, green, and white. We predicted the red and yellow mimicry ring would be found in red light habitats, while the blue and black mimicry ring would be found in blue light habitats. We further predicted that a red and yellow individual would have a stronger signal in the red environment than a blue and black individual and vice versa. We measured light environments (via irradiance and canopy cover) along transects where the mimicry rings are found. Behavioral trails were conducted to determine if butterflies had a preference for a light environment that granted a stronger signal and we employed visual models to verify that light environments would influence the perception of coloration of the different mimicry rings. We found that light habitats did differ among mimicry rings and that butterflies preferred different light environments. We show the effects of disparate light environments on the signal strength of the mimicry rings. This study demonstrates that different mimicry rings could evolve due to signal efficacy in different microhabitats.