Contents

01 March 2013
Vol 339, Issue 6123

About The Cover

Cover image expansion

COVER The rock pigeon (Columba livia) exhibits spectacular variation among more than 350 different domestic breeds. The adult male Old Dutch capuchine shown here is one of many breeds with a crest of reversed feathers on its head and neck. See page 1063 for a description of the genetic origins of the head crest and the relationships among breeds. For the story behind the cover, go to http://scim.ag/cov_6123. Photo: Sydney Stringham