The Pileated Woodpecker is the largest woodpecker found in most of North America, although the likely extirpated Ivory-billed Woodpecker (Campephilus principalis) in the southeastern United States and Cuba and the Imperial Woodpecker (C. imperialis) of western Mexico are larger.
Best recognized by its large, dull black body and red crest, the Pileated Woodpecker is a permanent resident of deciduous, coniferous, or mixed forests in southern Canada and in the western, midwestern, and eastern United States. Dead and deteriorating live trees provide favored sites in which to excavate nest cavities, and hollow trees are typically used to roost in at night. Only large-diameter trees have enough girth to contain the nest and roost cavities of this species, so there is concern for populations of this woodpecker where late-successional forests are being converted to younger stands. Availability of suitable habitat is apparently the factor limiting most populations. A pair defends its territory year-round, and a pair member will not abandon a territory even if its mate is lost.
Because of its size and strong chisel-shaped bill, this woodpecker is particularly adept at excavating, and it uses this ability to construct nest and roost cavities and to find food. Considered a keystone species, the Pileated Woodpecker plays a crucial role in many forest ecosystems in North America by excavating large nesting, roosting and foraging cavities that are subsequently used by a diverse array of birds and mammals—for shelter and nesting—particularly the larger secondary cavity users (e.g., Boreal Owl ]Aegolius funereus], Wood Duck [Aix sponsa], and American marten [Martes Americana]; Bull et al. 1997, Bonar 2000, Aubry and Raley 2002a). Pileated Woodpeckers accelerate wood decomposition and nutrient recycling by breaking apart snags and logs and may facilitate inoculation of heartwood in live trees with heart-rot fungi. They may also be important in helping control some forest beetle populations because their diet consists primarily of wood-dwelling ants and beetle larvae that are extracted from down woody material and from standing live and dead trees.