Despite being adept at climbing up the trunks of trees and hammering at wood to extract embedded insects, unlike other woodpeckers the northern flicker prefers to forage for food on the ground, hopping or running short distances between prey (3) (4). Ants may comprise as much as 75 percent of its diet (2), which it captures by hammering and digging at the soil, before darting out its long, barbed tongue at the end of the bill to snare its prey (3). The northern flicker also eats beetles, flies, butterflies, moths and snails, and often forages amongst other birds including sparrows and blackbirds, either alone, in pairs, in family groups, or in flocks of up to 15 birds (2) (3). When startled, unlike most other woodpeckers which quickly clamber up a nearby tree trunk, the northern flicker alights upon a thin horizontal branch and sits in a characteristic erect posture. It flies in a smooth rising and falling motion as it alternates periods of flapping with gliding (3).
The northern flicker is monogamous, with pairs mating for life, and produces two broods of chicks per season (2). The timing of breeding depends on the location but generally occurs between April and July. A territory is vigorously defended around the nesting site, which is usually a cavity excavated over 5 to 20 days by both the male and female bird in a dead tree, or a dead branch of a live tree (2). Pairs defend this territory by drumming loudly against a tree and also by confronting rivals in displays called a ‘fencing duel’, in which two birds face each other with the bills pointed upwards and the head rapidly twisted and bobbed (2) (3) (4). These displays also serve to reinforce the bond between breeding birds (4). The nest cavity has a narrow entrance but widens at the bottom to make room for the eggs and the incubating bird, which lies upon a bed of wood chips (3). A clutch of 4 to 9 eggs is usually laid and then incubated by both adult birds for 11 to 12 days. The chicks are fed on regurgitated food, largely by the adult male. They fledge from the nest at around 25 to 28 days old, but remain with the adult birds for an additional 15 to 20 days before becoming fully independent (2). The northern flicker first breeds at one year of age, with the oldest known bird having lived to nine years and two months of age (2) (3).
The northern flicker is also unusual for being one of few North American woodpeckers that exhibits strong migratory behaviour (3). Those populations in the southern and central parts of the species’ range may remain in the same location all year round, but those at more northerly locations tend to travel southwards before the onset of winter (2) (3). Typically, they leave the northern breeding grounds from the end of august to late October or November, with most birds departing in September. Whilst migrating, the northern flicker flies low over the ground, often in large flocks, and does not return to the breeding grounds until early March to May the following year (2).