Meeting Abstract

94.2  Monday, Jan. 6 13:45  Sexually dimorphic learning in a butterfly: learning biases, mate choice, and sexually dimorphic ornamentation WESTERMAN, E.L.*; MONTEIRO, M.; University of Chicago; National University of Singapore ewesterman@uchicago.edu

Mate preferences are learned in a wide variety of taxa with sexually dimorphic ornamentation. However, it is unclear what role sexual dimorphism in mate preference learning plays in the evolution of sexually dimorphic traits. Here we explore sexual dimorphism in preference learning using the butterfly Bicyclus anynana. Naïve female B. anynana butterflies prefer males with wild type forewing ornamentation (two dorsal eyespots) to males with more forewing ornamentation (extra dorsal eyespots), and learn preferences for more, but not less, forewing ornamentation. Number of eyespots varies on dorsal hindwings in both sexes, and is sexually dimorphic. We tested naïve preference and mate preference learning for dorsal hindwing eyespot number (DHSN) in both males and females. Neither sex exhibited naïve mate preferences. Males, but not females, learned preferences for DHSN. Male preference learning is biased, and biased in a different direction from female forewing preference learning – males learn preferences for females with less, but not more, DHSN. Female behavior during the learning period influences male hindwing mate preference learning, while male behavior during the learning period does not influence female forewing mate preference learning. We therefore demonstrate that mate preference learning in B. anynana is sexually dimorphic in terms of what traits are learned, direction of learning biases, and what premating experience influences preference learning. These findings illustrate the potential for sexual dimorphism in learning ability to influence the evolution of sexually dimorphic ornamentation.