One of the most easily recognized birds in the eastern United States, this aptly named species is perhaps the best example of a sexually monomorphic woodpecker, with adult males and females being indistinguishable in the field. The Red-headed Woodpecker is a highly omnivorous species, the most expert and persistent flycatcher in its family, and one of only four woodpeckers in the world that commonly stores its food.
Over the last 200 years, this species has undergone periods of great abundance and great scarcity, when it appeared to be on the verge of extinction. Ornithologists in the early 1900s were baffled by its erratic occurrence. Nonbreeding-season movements were historically influenced by nut crops in extensive American beech (Fagus) forests, which no longer exist, and contemporary movements are likely influenced by large-scale variations in the abundance of acorns. Breeding populations may have benefited from the demise of American chestnut (Castanea dentata) and American elm (Ulmus americana) trees from the eastern deciduous forest, but may have been adversely affected by the disappearance (or possible extinction) of a formerly abundant grasshopper in the Midwest. Recently, Red-headed Woodpecker populations have declined in most regions that support the bird, so the species is now listed as Threatened in Canada and several U.S. states.
This brilliantly colored bird has had a variety of colorful common names, such as white-shirt, half-a-shirt, shirt-tail bird, tricolored woodpecker, jellycoat, flag bird, and the flying checker-board. The Red-headed Woodpecker inspired Alexander Wilson to become an ornithologist ( Forbush 1927b ), was one of the first birds Ludlow Griscom learned to identify ( Davis 1994a ), and caught the fancy of Lawrence Kilham, who went on to a distinguished career studying woodpeckers ( Kilham 1983a ). It was a war symbol of Cherokee Indians, and its head was used as a battle ornament, particularly by Plains tribes ( Witthoft 1946 ). This was the woodpecker whose head Hiawatha dipped in the blood of Pearl Feather in Longfellow's poem ( Taverner 1953 ).
The conspicuousness of this species has led to a plethora of short notes and general accounts, with mostly anecdotal information. Many aspects of its behavior and ecology were first elucidated by the long-term observations of Lawrence Kilham (summarized in Kilham 1983a ). Few individuals have been color-banded, so little is known about differences in behavior or ecology of the sexes. Quantitative breeding information was first published only a few decades ago ( Reller 1972 , Jackson 1976a ), followed by other studies on this species' use of breeding habitat and its nest success across its range (Rodewald et al. 2005, Vierling and Lentile 2006, King et al. 2007, Frei et al. 2013, Hudson and Bollinger 2013). There remains little information regarding the growth and development of nestlings, likely owing to the species' propensity to nest in inaccessible locations, i.e. snags or dead branches.
As with many cavity-nesting species, Red-headed Woodpecker may compete intra- and inter-specifically for nesting sites, especially in areas where nest sites are scarce. Numerous aggressive interactions with the non-native European Starling (Sturnus vulgaris) have been reported. The likelihood of competition for nest sites contributing to declines of this woodpecker has varying degrees of support in the literature, perhaps a result of differences between breeding phenology and habitat structure across the range of this species.
Although the Red-headed Woodpecker is a charismatic and easily recognized species, its often precariously placed, hard to reach nest sites, and unpredictable winter population fluctuations makes studies of the species challenging to researchers. This, in part, may explain the surprising lack of basic information for the species, compared to other woodpeckers in North America. Boosting levels of knowledge would help future efforts for conservation and recovery planning.