Northern Flicker Colaptes auratus Scientific name definitions

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

Conservation and Management

Conservation Status

The Northern Flicker is not listed as a species of concern by the federal governments in Canada or the United States. BirdLife International recognizes the Northern Flicker as three distinct species, Yellow-shafted Flicker (Colaptes auratus), Red-shafted Flicker (Colaptes cafer), and Guatemalan Flicker (Colaptes mexicanoides), but all of these taxa are ranked as species of Least Concern (292). The Northern Flicker is widespread and common across much of North America (see Population Status).

Effects of Human Activity

Humans alter the environment in ways that may be both detrimental and beneficial for Northern Flicker populations. Although the Northern Flicker remains common, the long-term declines within some North American populations are cause for concern. There have been no rigorous, focused studies to identify the cause of declines but there are 4 common hypotheses: (1) competition for nest cavities from the introduced European Starling (Sturnus vulgaris), (2) declining availability of suitable nest-cavity substrate (snags, dead limbs, and live trees with heart rot), (3) the loss of aspen habitat as a result of fire suppression, and (4) pesticide application on golf courses, agricultural fields, and suburban lawns.

Habitat Loss and Degradation

The removal of snags during forestry operations and urban development seems to reduce habitat suitability by removing nest sites (293). On the other hand, flickers favor open landscapes and relatively open forest structure, so disturbances such as fire, logging, or insect outbreaks that open up the forest floor and increase the abundance of standing dead wood are positively associated with local population increases. Northern Flicker is among the species with increasing population density in an increasingly fragmented boreal forest region (294; see also Population Regulation). Fire suppression within grassland-aspen habitats in the western United States may lead to conifer encroachment and ecological succession which reduces habitat suitability for the Northern Flicker (295).

Effects of Invasive Species

A decline in Northern Flicker populations in the southeastern and central United States and Canada has been attributed to competition with European Starling (296, 297), but Koenig (298) failed to find negative correlations between starling and flicker populations using Christmas Bird Count data. However, such survey data may be rather coarse and there are many reports of starlings usurping nest cavities from Northern Flickers (299, 9, 300, 301, 131, 206). In some populations, the rate of nest loss to starlings appears to be high. For example, 40% of flicker nests were lost to starlings in Miami, Florida (302) and 68% of flickers on a study site in Ohio lost their nests to starlings although nest boxes were experimentally placed near the cavities to provide accommodation for starlings (303). The delayed nesting of flickers caused by competition with starlings reduces reproductive output (304). The intensity with which a flicker defends its nest is related to past experience with starlings, but often defense is unsuccessful (194). The impact of nest usurpation at the population level may depend on whether a flicker can renest after being displaced, but the seasonal decline in clutch size means there is still a reproductive cost to eviction (254). More study is needed on how various rates of nest usurpation in different flicker populations translate to reduced productivity at the population level.

Shooting and Trapping

Historically, often taken by gunners. Stone (147) described the slaughter at Cape May, New Jersey: “Not many years ago Flickers were lawful game in New Jersey, and the Cape May gunners, well versed in the character and time of these flights [fall migration], made regular preparation for them. Poles or fence rails were fastened to the tops of the low pines and cedars at the Point so they projected upward above the topmost branches and formed resting places that the Flickers could not resist. The result was that the tired birds, stopping for a few moments on their wild flight, lined the poles so that at any moment six or more were clinging to the perches and a gunner concealed at the base of the tree ‘raked' them off with the greatest ease...two gunners secured six peach baskets full of flickers on a single morning and piles of dead birds as high as a man's knees were frequent sights....” Such slaughter is, of course, a thing of the past.

Pesticides and Other Contaminants/Toxics

Anecdotal deaths from pesticides are reported (272), but there is presently no evidence that populations are particularly at risk from chemicals.

Collisions with Stationary/Moving Structures or Objects

Collisions with vehicles, windows, wind turbines, and communications towers are known to occur. Northern Flicker was among the 25 most common bird species to be struck by wind turbines in some parts of North America, but not in others (270). It can also fall victim to colliding with windows (271) and communications towers (148). It was listed among those species with higher than average risk for collisions with buildings (305). Study is needed on the population-scale impacts of collision-related mortality.

Other Human/Research Impacts

Because the Northern Flicker commonly nests in or near human habitation it seems to be able to adapt to many disturbances. It is tolerant of human activity in the vicinity of a nest site; at least once a parent is committed to incubation or feeding nestlings. During sanctioned research activities, Northern Flickers were trapped in nest cavities for banding, and after these brief nest visits by humans, adults returned to the nest and continued regular parental care (KLW, WSM).


Conservation Measures and Habitat Management

Conservation of the Northern Flicker is important because this is the primary predator on ants in woodland habitats and because it acts as a keystone species by excavating a large percentage of the nest cavities used by numerous secondary cavity-nesting species (5). The loss or reduction in flicker numbers would likely have a large impact on the biodiversity of vertebrates in most woodland ecosystems in North America. Because it has not been recognized as a threatened species, few conservation measures have been proposed and no specific actions appear to have been taken. Especially in areas with possible population declines (e.g., eastern North America), basic research is needed to determine whether nest-substrate availability limits populations. More extensive experiments involving manipulation of snag density, similar to studies of Scott and Oldemeyer (277), would be useful.

Several factors may contribute to a reduction in nest-cavity substrate: expansion of suburbs; policies for removing snags, dead limbs, and diseased trees from urban and suburban areas (306); and inadequate or unenforced snag and dead-limb maintenance policies in forests. Effective management policies must consider the dynamic-equilibrium of the snags and dead limbs that comprise the standing crop (307) and a range of decay classes of trees needs to be maintained to ensure a continual turn-over and a supply of fresh cavities (308, 197). In forested areas, snags should be left in harvested and burned areas (278, 232). Thomas et al. (309) estimated that 93 snags/100 ha would result in flicker populations reaching 100% of their potential density in several western woodland communities. The retention of aspen trees in blocks of harvested boreal forest was linked to increased populations of flickers after harvest (199). Flickers apparently ignored artificial snags placed in clearcuts (310).

In other ecosystems it may be important to allow natural disturbance regimes that keep the landscape structure open. For example, restoring open oak habitats in Oregon and California by removing encroaching conifers lead to an increase in flickers (311). The loss of trembling aspen (Populus tremuloides) woodland, a favorite nesting substrate of flickers, as a result of aspen die-off or fire suppression often results in conifer encroachment. Maintaining natural disturbance levels in such ecosystems is important as flickers avoided dense conifer areas and settled within aspen/grassland edges (295).

As a result of numerous observations of the introduced European Starlingevicting flickers from nests (see Effects of Invasive Species) some have recommended placing nest boxes to reduce competition over cavities. In an experiment, Ingold (303) placed nestboxes beside flicker cavities, but 68% of flickers still lost their nests to starlings, despite available boxes.

Effectiveness of Measures

Because it is not recognized as a threatened species, no conservation measures have been officially enacted or studied.

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