Sexy and Delicious.

BIRD surveys; BIRDS; BIRD behavior; BIRD population estimates; ECOLOGICAL surveys; PROCEEDINGS of the National Academy of Sciences of the United States of America (Periodical); PREDATION; BIRDS of prey

Having extra color may help male birds woo mates, but it also attracts predators. Scientists analyzed 21 years of data from the North American Breeding Bird Survey, which thousands of volunteers across the continent gathered by counting all birds seen or heard during breeding-season mornings. On average, wildlife ecologists find that 'dichromatic' bird species die out nearly 25 percent more often than their monochromatic relatives. Two-toned birds in general do not go completely extinct, because as soon as one species vanishes from a neighborhood, other colorful ones take its place. The report, appearing in the April 17, 2003 'Proceedings of the National Academy of Sciences USA,' supports the theory that species under strong sexual-selection pressure face greater risks of becoming locally extinct and suggests that human activities that block migrations could jeopardize the survival of dichromatic species.