25 January 2008
Vol 319, Issue 5862

About The Cover

Cover image expansion

COVER A male lark bunting in the Pawnee National Grassland, Colorado. The plumage quality of the males determines their reproductive success, but different aspects of the black and white markings are preferred by females in different years. This variability alters the long-term sexual selection dynamics and may favor the evolution of multiple sexual ornaments. See page 459. Photo: Bruce Lyon