SPECIES

Northern Flicker Colaptes auratus Scientific name definitions

Karen L. Wiebe and William S. Moore
Version: 2.0 — Published July 7, 2023

Behavior

Locomotion

Walking, Running, Hopping, Climbing, etc.

Hops or walks slowly for short distances on the ground when foraging. Bent (9) reported that they occasionally ran for short distances, but this was not observed during long-term research at Riske Creek, British Columbia (KLW). Hops on tree branches, limbs, and vertical trunks, moving up, down, or laterally with short hops and using stiffened rectrices as a brace when clinging to a trunk.

Flight

Sustained flight has an undulating trace, termed “flap-bounding” which is typical of woodpeckers. Bursts of wing-flapping alternate with non-flapping phases (bound) during which wings are folded against the body (176). Analysis of video recordings and 16-mm film of a Northern Flicker flying to and from 7 nests in Montana yielded mean estimates of flight parameters: airspeed 9.6 m/s (range 7.7–11.6); flaps between bounds 3.6 (range 1–5); wingbeat frequency 8.6 Hz (range 6–10); flapping-phase duration 256.7 ms (range 133.3–600); bound-phase duration 211.1 ms (range 116.7–416.7); and percentage of cycle flapping 52.9% (range 43.75–71) (176). Flaps continuously when taking off and ascending and use brief glides interrupted by bounds when landing (176). In Florida, estimates of airspeed 11.3 m/s ± 2.8 SD and wingbeat frequency 8.72 Hz ± 1.4 SD (177).

Self-Maintenance

Preening, Head-Scratching, Stretching, Sunbathing, Bathing, Anting, etc.

Perches for extended periods during the breeding season when not incubating, brooding, or foraging, especially in late afternoon and evening and often preens during this time. During the nestling period, parents spent, on average, 1.5% of the daytime time budget preening (161). Kilham (133) reported the following behaviors for the Northern Flicker and all other woodpeckers he observed: they scratch their heads directly without lowering a wing, as is characteristic of most passerines; they pass the bill over an oil gland, then rub the bill with a foot before head-scratching, apparently transporting oil to head feathers; they do not stretch a leg on the same side of the body as they stretch the wing, as is typical of birds, but stretch just the wing. Kilham (133) also reported a pair scratching their heads vigorously every few seconds while foraging for ants on a lawn in Florida; he thought they were dislodging ants of a particularly irritating species that were getting among the head feathers. Flickers also dust-bathe (178) and "ant" —intentionally smear ants over their plumage (179). No reports of sunbathing or bathing in water.

Sleeping, Roosting

May sleep clinging to a vertical surface with the head tucked under scapula feathers (132). During incubation and the early nestling (brooding) period, the male sleeps in the nest cavity. Royall and Bray (134) reported the following on roosting, based on radio-tracking of 4 individuals during the nonbreeding season from 18 February–8 April: arrived at roost 4–9 min after sunset and left roost 11–25 min before sunrise; roosted on trees or in tree cavities, also on buildings and underneath bridges, usually in a sheltered niche, e.g., under eaves of a building, and in one case, in a metal cylinder under the eaves. Two individuals used the same roost every night, the other two varied roost sites; 1 bird occupied 11 sites in 132 nights. Other anecdotal observations indicate similar roosting behavior (145, 9). Analysis of light levels from geolocators on 17 tagged individuals from Riske Creek showed that 49–89% of nights during fall and spring migration were spent in a cavity, and 59‒91% of nights were spent in a cavity on the wintering grounds (154). Northern Flickers roosted (singly) in 20% of 79 nest boxes originally built for American Kestrel (Falco sparverius) during the wintering period in Idaho (180).

Daily Time Budget

Using radio-telemetry, Royall and Bray (134) tracked 4 individuals in the nonbreeding season (18 February–8 April) in Colorado. When they were not flying, the birds spent 77% of their time on trees, poles, and other elevated sites and were on the ground 23% of the time. Since Northern Flicker forages primarily on the ground and spends little time on the ground when not foraging, this may be a rough estimate of foraging time allocation during late winter. During the breeding season (May–June), 39 females and 38 males were radio-tracked during daylight hours (161). Females spent significantly more time foraging (50% of time budget) than males (45%). Males spent more time in the nest brooding and tending the young (26% of time) than females (21%). Average time spent perching (21%), flying (2%), and engaging in social interactions (0.7%) did not differ between the sexes. The time spent foraging increased and brooding decreased as brood size increased. Cold or rainy weather was associated with reduced time spent foraging (161).

Agonistic Behavior

Physical and Communicative Interactions

Both sexes defend nest trees and mates aggressively. Agonistic behavior is highly ritualized in flicker “dance” (Figure 6). Typically, two birds of the same sex pair off in duels that resemble fencing, using their bills as “foils,” while a member of the opposite sex looks on. This dance is prevalent during early phases of the breeding cycle (territory establishment, pair formation, and nest-site selection), but also occurs infrequently and at lower intensities at other times (11). Displays that comprise the dance are clearly agonistic (181) and function in territorial defense, but territorial establishment and pair formation are so integrated in Northern Flicker that these displays may also play a role in pair formation; this remains poorly understood.

During the dance, sometimes called a "fencing duel" or a "Wicka Bout" because of the accompanying vocalization, two birds (usually of the same sex) face one another on a branch or on the ground with their bills held at a slightly upward angle (about 30° from horizontal). Each bird quickly swings its head back and forth and bobs it up and down, such that the bill appears to trace a circular or figure-8 pattern in the air (172, 146, 97). The swinging and bobbing give the appearance of a mechanically animated toy and are usually accompanied by in-rhythm Wicka calls from both dancers. The red nuchal patch is usually erected in Yellow-shafted Flickers. Intensity of the dances varies greatly: the dance of two birds (same sex) often is of relatively low intensity and may even be silent, but the arrival of a third bird (opposite sex) immediately intensifies both the dance and the Wicka accompaniment. In very intense interactions, which are common, the dancers flick their wings and spread or rotate their tails such that the yellow or red ventral surfaces of the flight feathers are clearly visible to the opponent. Bursts of dancing and Wicka-calling might last 5–10 s, followed by a 30–s period of quiescence, followed by another burst of dancing where all participants seem compelled to join in. Bouts may last nearly half an hour (but usually are shorter) and may be joined and rejoined over a period of many hours. We have observed sustained series of dance bouts go on essentially all day, involving the same participants. Variation in the dance is substantial: the apparent context, number of participants, location, intensity, duration, whether the wings and tail are spread, whether Wicka calls accompany animation, and the pattern traced by the bill can all vary. No quantitative data on the display are available that demonstrate the range of variation or its meaning.

Flicker dances often do not result in physical contact but instead one bird simply flies away. If one bird does not fly away after many minutes of dancing, the two rivals may begin to peck and claw at each other. This usually results in a long period of one bird chasing the other, displacing it from perch to perch in short flights until eventually the "loser" flies away out of apparent exhaustion. Rarely, physical fighting escalates to a rolling fight on the ground (KLW), and one individual is sometimes killed as a result (182).

Territorial Behavior

Male and female vigorously defend the space around their nest tree with Long-calling, drumming, displays, and Wicka dances (183), but do not defend a feeding territory probably because their main prey (ants) are not economically defendable (167). Instead, breeding Northern Flickers may forage together in loose groups with conspecifics where home ranges overlap. The size of the defended area around the nest tree may depend on the stage of breeding and on snag densities (more information needed). The shortest distance between two nests at Riske Creek was 5 m (two pairs breeding in adjacent trees), and active nests 30–50 m apart were not rare (KLW), suggesting a defended radius of 5–25 m around the cavity tree. The hypothesis that such close nesting is made possible by staggered breeding times (184) is not supported because many close-nesting pairs at Riske Creek had the same nesting schedules. There are two reports of two flicker pairs nesting simultaneously in the same tree, but this is rare (185). Distances between nests are determined by agonistic behavior but also depend on snag density, so one must be cautious about inferring territory size from distances between nests.

The species conducts its normal activities in undefended home ranges both in the nonbreeding and breeding seasons. In late winter, 4 individuals in Colorado occupied home ranges of 48‒101 ha (134). Monitoring radio-tagged birds during the breeding season at Riske Creek, British Columbia revealed home ranges (95% convex polygons) of 5‒109 ha (mean 25 ha, n = 52) (155). Home ranges overlapped somewhat with conspecifics and did not differ in size between the sexes, and neighbors occasionally foraged together without apparent agonism. Members of a breeding pair often foraged at different locations to avoid depleting food resources on the home range (162).

Sexual Behavior

Mating System and Operational Sex Ratio

Usually socially monogamous, but up to 5% of the population annually is polyandrous at Riske Creek, British Columbia (186, 187). Polyandrous females lay eggs for 2 males in different tree cavities; the clutches are slightly staggered in time. While the female shares incubation at the first nest, she may be laying eggs at the second. Females spend a reduced amount of time incubating the second nest while they are feeding nestlings at their first nest (188). Males seem to compensate for reduced female participation, and both clutches of a polyandrous female may be raised successfully. Polyandry seems to result from a local shortage of females; a male that calls for weeks in spring without attracting a female often becomes polyandrous with a neighboring female (189). However, the frequency of polyandry may be low in most populations because there seems to be little sex ratio bias of adults (187). More studies of pairing in other populations are needed to determine whether polyandry is widespread and what its proximate causes may be.

Male and female share parental care through the breeding season, but sex roles are partly reversed with males doing more parental care especially at the early stages of the reproductive cycle (161, 187).

Courtship, Copulation, and Pair Bond

Courtship. The "Wicka dance" (see Agonistic Behavior) seems to function also in courtship because it is intensified between two members of the same sex when a member of the opposite sex arrives and looks on. Also, low-intensity dances accompanied by soft Wicka calls occur between members of a pair. Ritualized tapping occurs between male and female as they choose a nest site and could be considered an aspect of courtship behavior (see Nonvocal Sounds). Mate guarding is not reported.

Copulation. Occurs regularly throughout day without much display (11). Male and female rotate “guard duty” at the nest through much of the nesting cycle. Usually only 1 adult is at the nest at any given time; the “off-duty” adult usually leaves the nest area. Before and during egg-laying, the pair usually copulates when the female returns to the nest, about every hour. Noble (181) described a nasal we-we-we call given by the female as a “call-to-mate” vocalization, but also reported that it was not always given. Soft Wicka calls are often given as an off-duty adult returns to the nest, but copulation usually follows quickly in silence, and the “spelled” adult quickly flies from nest area (KLW). Pairs usually copulate on a horizontal branch near the nest cavity. Female squats low and the male mounts and spreads his wings over her. Copulation lasts a few seconds; the male then usually quickly leaves the nest area, and the female flies to nest cavity.

Duration and Maintenance of Pair Bond. At Riske Creek in British Columbia, the within-season divorce rate was 4.6%, (i.e., among those pairs that lost a first nest to predators and attempted a replacement nest within the same season). Divorce rates between years was higher, averaging 15.5% (190). In the post-fledging period, no male deserted his brood before fledgling independence but 36% of females stopped feeding their fledglings while the male was still provisioning them. Radio telemetry showed that these "deserting" females often moved away from the home range, Wicka-danced with neighboring males, or investigated other cavity trees with little subsequent contact with their mate or offspring that breeding season (191). At least for migratory populations, there is no indication that pairs migrate, or winter, together.

Extra-Pair Mating Behavior/ Paternity

Flickers are unusual among biparental bird species in that genetic monogamy is the norm. Analysis of DNA microsatellites revealed no cases of extra-pair paternity in a sample of 326 nestlings from 46 socially monogamous broods (189).

Brood Parasitism of Conspecifics

Can occur, especially in dense populations. At Riske Creek in British Columbia, microsatellite (DNA) analysis showed that 17% of broods contained at least one parasitic egg (189). In five cases, the identity of the parasitic female was known: it was a neighboring female with a mate and clutch of her own. A "foreign" female may sometimes try to enter the nest cavity of a breeding pair, presumably to lay a parasitic egg, but the resident pair vigorously attacks and tries to block the entrance (KLW). Bower and Ingold (192) also reported a case of conspecific parasitism, and Burkett (193) described two instances of apparent attempts by interloping females to enter the nest cavity of an established pair; the resident male and female both defended against persistent attempts. Burkett (193) argued that the combined behaviors of nest guarding and copulation each time the female returns to the nest prevent nest parasitism and assure paternity, respectively.

Brood Parasitism of Other Species

Not known to occur.

Social and Interspecific Behavior

Degree of Sociality

Not social but may forage in loosely structured groups at any time of year; e.g., Kilham (133) observed 20 flickers foraging together in a corn field thinly covered with snow. Ten males foraged together on a park lawn in Detroit, Michigan, in early April; individuals were never closer than 3–4 m, but all were within a 25-m radius (WSM).

Play

No clear case reported in the literature.

Nonpredatory Interspecific Interactions

The Northern Flicker competes with other cavity-nesting species for nest cavities, especially the European Starling (Sturnus vulgaris), often resulting in physical attack (see Management). The level of aggression towards starlings depends partly on learning and past experience with defending nest cavities (194). The pugnacious Tree Swallow (Tachycineta bicolor) also may evict Northern Flickers from a cavity early in spring. Less frequent but intense competition for nest cavities with other species such as the American Kestrel; Northern Flicker is known to evict American Kestrels from holes and destroy their eggs (WSM), but may also be chased from cavities by American Kestrels (KLW). May occasionally destroy eggs of Bufflehead (Bucephala albeola) to take the cavity (KLW), and Northern Flickers reportedly injured a Whiskered Screech-Owl (Megascops trichopsis) nestling in an attempt to take over the cavity (195). Northern Flickers may share a nest tree with several other species including Red-headed Woodpecker (Melanerpes erythrocephalus), American Kestrel, European Starling, Tree Swallow, Mountain Bluebird (Sialia currucoides), and several others (WSM, KLW, 196, 185).

The Northern Flicker also plays an important role in many ecosystems as a keystone species by excavating a large percentage of the nests which numerous secondary cavity-nesting species depend on for their own reproduction (5). The intermediate body size of the Northern Flicker relative to other woodpecker species and its relative abundance makes their cavities more accessible to a wide range of secondary users. The importance of their nest-building role within ecosystems has been quantified in central British Columbia (197, 198), in the Canadian boreal forest (199), in the burned forests of the Black Hills in South Dakota (200), and in the pine forests of the southern United States (201). The Northern Flicker also increases cavity availability by enlarging the cavities created by other woodpecker species (202 ,203) and prolongs the use of a hole by cleaning old, dirty cavities of debris (202).

Predation

Kinds of Predators and Manner of Predation

Numerous anecdotal reports. Adults and especially fledglings taken by several species of hawks: Cooper's Hawk (Accipiter cooperii), Sharp-shinned Hawk (Accipiter striatus), Broad-winged Hawk (Buteo platypterus), Red-shouldered Hawk (Buteo lineatus), Northern Harrier (Circus hudsonius), and probably most other species of large hawks (132, 9). One fledgling was observed to be killed by an American Kestrel during its "maiden flight" from the tree cavity (KLW). Mammals like red fox (Vulpes vulpes) may kill adult Northern Flickers (204), and in urbanized areas, domestic cats are also predators (205).

At Riske Creek, British Columbia, the main nest predator was red squirrel (Tamiasciurus hudsonicus), which takes both eggs and nestlings (206). Other known nest predators on the site were northern flying squirrel (Glaucomys sabrinus), short-tailed weasel (Mustela erminea), American mink (Neovison vison), fisher (Martes pennanti), and black bear (Ursus americanus). At other locales, raccoon (Procyon lotor) is a suspected predator of adults and nestlings (WSM), and southern flying squirrel (Glaucomys volans), long-tailed weasel (Mustela frenata), Red-headed Woodpecker (Melanerpes erythrocephalus), American Crow (Corvus brachyrhynchos), Fish Crow (Corvus ossifragus), and Blue Jay (Cyanocitta cristata) are reported (132). In southern locales, ratsnakes (Pantherophis sp.) and bull snake (Pituophis catenifer sayi) eat nestlings (9, 207). The bull snake is an adept tree climber, and has been seen in flicker nest cavities as high as 8 m up a vertical trunk; the snake crawls into the cavity, eats the hatchlings, and remains in the cavity for several days (WSM).

Larger predators such as black bear and fisher that cannot fit through the entrance hole get access to nests by ripping open the sides of the tree; thus soft and decayed snags are more vulnerable to them. On a study area in Washington State, 9.1% of Northern Flicker cavities (n = 78) were destroyed by black bear—the low down cavities in decayed pine stumps were especially vulnerable (208). At Riske Creek, cavities that were higher above the ground, that had vegetation concealing the area around the entrance hole, and that were farther from coniferous forest edges were safer from predators (206). However, cavities that were closer to coniferous edges were safer from usurpation by European Starling, so the choice of nest site may involve trade-offs between the risk presented by different suites of predators/competitors (206).

Response to Predators

The Northern Flicker does not appear to respond strongly to avian or reptilian predators; e.g., it rarely mobs hawks, and one adult, confronted with a bull snake on a branch near its nest cavity, made only tentative flights and bill pokes at the snake (WSM). It defends the nest against squirrels by poking out of the cavity entrance and pecking the mammal or pecking and diving at the squirrel on the tree trunk (209). Frequently, one member of the pair blocks the nest hole while the other dives at the squirrel. Perhaps as a result of predation risk from hawks, adult Northern Flickers foraged nearer to trees, saplings, and forest edges (escape cover) than expected by chance (156), and foraged in loose flocks with conspecifics or American Robin (Turdus migratorius) and European Starling to aid in predator detection.

Although the Northern Flicker tended to change to a new nest site after being depredated, new sites were not significantly safer from predators (137).

Recommended Citation

Wiebe, K. L. and W. S. Moore (2023). Northern Flicker (Colaptes auratus), version 2.0. In Birds of the World (P. G. Rodewald, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.norfli.02