Adult Red-bellied Woodpeckes are mainly light gray on the face and underparts; they have black and white barred patterns on their back, wings and tail. Adult males have a red cap going from the bill to the nape; females have a red patch on the nape and another above the bill. The reddish tinge on the belly that gives the bird its name is difficult to see in field identification. They are 22.85 to 26.7 cm (9.00 to 10.51 in) long, have a wingspan of 38 to 46 cm (15 to 18 in), and weigh from 2.0-3.2 oz (56-91 g).
The English naturalist Mark Catesby described and illustrated the Northern Flicker in his book The Natural History of Carolina, Florida and the Bahama Islands which was published between 1729 and 1732. Catesby used the English name “Gold-winged Wood-pecker” and the Latin Picus major alis aureis. When in 1758 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the tenth edition, he included the northern flicker, coined the binomial name Cuculus auratus and cited Catesby’s book. The specific epithet auratus is a Latin word meaning “gilded” or “ornamented with gold”. The type locality is South Carolina. The northern flicker is one of 13 extant New World woodpeckers now placed in the genus Colaptes that was introduced by the Irish zoologist Nicholas Aylward Vigors in 1825 with the northern flicker (Colaptes auratus) as the type species.