Either of two species of North American woodpeckers that drill holes in neat, close rows to obtain sap and insects. The yellow-bellied sapsucker (Sphyrapicus varius), about 8 in. (20 cm) long, is one of the few migratory species of woodpecker, breeding in northern regions and southern mountains and migrating as far as the West Indies and Central America. Both sexes have bold head markings. Williamson's sapsucker (S. thyroideus), which lives in high pine forests of the western U.S., is uncommon throughout its range