Meeting Abstract

94.1  Monday, Jan. 6 13:30  Effects of domestication on sexual dichromatism in the island canary KOCH, R.E.*; HILL, G.E.; Auburn University; Auburn University rek0005@auburn.edu

In many songbird species, males exhibit flashier and more colorful plumage than females. This sexual dichromatism is commonly accepted to arise through sexual selection, though research on the topic is heavily biased toward largescale phylogenetic analyses. Domestic species present an interesting but rarely studied system in which reproductive success is determined not by natural and sexual selection but by artificial selection for traits considered desirable by humans. In domestic individuals, we may therefore examine how sexually dichromatic traits evolve when released from the selection pressures presented by male-male competition, female mate choice, and predation. We investigated the effects of domestication on sexual dichromatism in the island canary (Serinus canaria), the only songbird that has been bred in captivity over several centuries to produce a multitude of domestic breeds. We used a reflectance spectrometer to quantify dichromatism in the wild progener population of canaries and in captive canaries bred for bright yellow plumage coloration. The sexual dichromatism evident in wild canaries is no longer detectable in modern domestic breeds, indicating the powerful effects of artificial selection and captivity on the coloration of both sexes in this species. The implications of loss of sexual dichromatism in captive breeds of canaries on evolution of dichromatism will be discussed.