Meeting Abstract

48.3  Sunday, Jan. 5 10:30  In the Eye of the Beholder: Intraspecific Variation in Retinal Physiology and Modeled Visual Perception in Two Species of Passerines ENSMINGER, A.L.*; ELMORE, A.G; PITA, D.L.; FERNANDEZ-JURICIC, E.; Purdue University, West Lafayette, IN; Purdue University, West Lafayette, IN; Purdue University, West Lafayette, IN; Purdue University, West Lafayette, IN amanda.ensminger@gmail.com

Many theoretical models on anti-predator behavior, foraging behavior, and mate-choice assume that there is no intraspecific variation in visual perception. We tested whether individual house finches differ in the absorbance of their oil droplets (which influences the ability to distinguish between different colors), and whether house sparrows vary in the absolute density of cones (which affects spatial resolving power), and in the relative density of single and double cones (which affects chromatic/achromatic contrasts). We found that, for all types of photoreceptors, individual house finches differed significantly in oil droplet absorbances, and that these translated into differences in modeled estimates of chromatic contrast. For house sparrows, we found significant individual differences in the density of cones, overall and for each type, as well as relative densities and ratios of types. These translated into significant individual differences in modeled estimates of perception (both chromatic contrast and anatomical spatial resolving power). Further, we found that cone densities of each type were positively correlated, and that individual estimates of chromatic contrast did not correlate, either positively or negatively, with estimates of spatial resolving power. These results have relevant implications for intraspecific variation in behaviors of fitness consequence.