About Colaptes auratus (Linnaeus, 1758)
This is the description of the northern flicker, Colaptes auratus (Linnaeus, 1758). Adults are brown with black bars across their back and wings. This mid- to large-sized woodpecker measures 28–36 cm (11–14 in) in total length, with a wingspan of 42–54 cm (16+1⁄2–21+1⁄2 in). Body mass ranges from 86 to 167 g (3 to 5+7⁄8 oz). Standard scientific measurements for the species are: the wing bone measures 12.2–17.1 cm (4+13⁄16–6+3⁄4 in), the tail measures 7.5–11.5 cm (3–4+1⁄2 in), the bill measures 2.2–4.3 cm (7⁄8–1+11⁄16 in), and the tarsus measures 2.2–3.1 cm (7⁄8–1+1⁄4 in). The largest-bodied specimens come from the northern stretches of the species' range, at the latitude of Alaska and Labrador, while the smallest specimens come from Grand Cayman. A black, necklace-like patch is present on the upper breast. The lower breast and belly are beige, marked with black spots. Males can be distinguished by a mustachial stripe at the base of the beak: this stripe is black in the eastern part of the species' range, and red in the western part. Females do not have this mustachial stripe. The top of the tail is dark, transitioning to a conspicuous white rump that is visible when the bird is in flight. Plumage varies between different subspecies. Northern flickers can be found in open habitats near trees, including woodlands, forest edges, yards, and parks. In the western United States, they can be found in mountain forests all the way up to the tree line. Like other woodpeckers, northern flickers generally nest in holes in trees. Occasionally, they have been recorded nesting in old earthen burrows that were vacated by belted kingfishers (Megaceryle alcyon) or sand martins (Riparia riparia). Both sexes help excavate the nest. The nest entrance hole is about 8 cm (3 in) in diameter, and the nesting cavity is 33–41 cm (13–16 in) deep. The cavity widens at the bottom to create space for eggs and the incubating adult. The inside of the cavity is almost entirely bare, with only a bed of wood chips for eggs and chicks to rest on. Once nestlings reach around 17 days old, they begin clinging to the cavity wall instead of lying on the cavity floor. Northern flickers can also create cavities inside human homes, particularly homes with stucco or weak wooden siding. The breeding range of the northern flicker covers forested areas across North America, extending south as far as Central America. This species is a cavity nester that typically nests in trees, but it may also use appropriately sized and sited posts and birdhouses. It prefers to excavate its own nesting cavity, though it may reuse and repair damaged or abandoned nests. These reused old nests are often created by belted kingfishers or sand martins. Abandoned northern flicker nesting cavities provide habitat for other cavity-nesting species. Sometimes, other cavity-nesting birds such as the common starling (Sturnus vulgaris) will displace northern flickers from their nesting sites. Northern flickers usually breed between February and July, with timing depending on the temperature of the local area. During the breeding season, mated pairs stay together; they do not remain paired after the breeding season ends. Before the breeding season starts, a mated pair needs one to two weeks to build their nest. Males attract females through head bobbing behavior and specialized mating calls. A common call males use toward females is a repeated woikawoikawoika sequence, which signals their pair bond to both their mate and other birds. When this call is given toward another male, it acts as a territorial signal. This call pattern is flat at the start, and gradually rises into a loud noise. The call itself is a chirp that includes drumming and rattling. Additional territorial displays toward other males include head swinging when near another male, and repeatedly striking objects with the beak to create loud noise. Males often use wood or metal to produce a louder sound. While producing these loud noises, males will spread their wings, move them up and down, and spread their tail to display their colorful underside. Feather color varies based on the surrounding environment; there is currently no confirmed link between feather color and mate choice, and feather color plays a larger role in territorial signaling. Northern flickers may also point their bill forward toward a competitor as a territorial display. Juvenile northern flickers are often defenseless against predators that enter the nest. Common predators of juveniles include Cooper's hawks (Astur cooperii), sharp-shinned hawks (Accipiter striatus), common raccoons (Procyon lotor), squirrels, and snakes. Full-grown northern flickers are preyed on by larger birds and hunting birds. The entrance hole of a northern flicker nest is roughly 5 to 10 cm (2.0 to 3.9 in) wide, and most often faces east to southeast. On average, northern flickers produce one to two clutches per breeding season. A typical clutch holds six to eight eggs. The eggs are pure white, with a smooth, highly glossy shell. Northern flicker eggs are the second-largest of any North American woodpecker species; only the pileated woodpecker has larger eggs. Both sexes incubate the eggs over a period of around 11 to 12 days. Usually, the male incubates overnight, while both the male and female incubate during the day. The young are fed by regurgitation, and fledge around 25 to 28 days after hatching.
