a small bird that runs very fast and lives mainly in deserts. or chaparral cock Either of two species of terrestrial cuckoo, especially Geococcyx californianus (family Cuculidae), of Mexican and southwestern U.S. deserts. About 22 in. (56 cm) long, they have streaked brown-and-white plumage, a short shaggy crest, bare blue and red skin behind the eyes, stout bluish legs, and a long tail carried at an angle. Clumsy, weak fliers, they prefer to run. Using their stout bill, they pound insects, lizards, and snakes to death, then swallow the victim head first. The lesser roadrunner (G. velox), of Mexico and Central America, is smaller, buffier, and less streaked