Northern Prairie Wildlife Research Center
The pileated woodpecker (Dryocopus pileatus) is a year-round resident of deciduous or coniferous forests in southern Canada and in the eastern and northwestern United States (Bull and Jackson 1995). The species relies on stands of mature trees for nesting, roosting, and foraging. The pileated woodpecker excavates nest cavities in dead trees, roosts in hollow trees, and forages for insects on downed woody material and on standing live and dead trees. Numbers of pileated woodpecker in the eastern United States prior to 1900 were diminished by tree-clearing activities and shooting (Bull and Jackson 1995). Regrowth of forests, the introduction of Dutch elm disease (Graphium ulmi), which results in dead and dying trees, and federal and state legislation granting protection to the species have contributed to a population increase (Nicholls 1994, Bull and Jackson 1995).
Prior to about the 1950's, the pileated woodpecker in North Dakota was primarily confined to the Agassiz Lake Plain region of eastern North Dakota (Stewart 1975). The Agassiz Lake Plain is the area of western Minnesota and eastern North Dakota that is drained by the Red River of the North (hereafter Red River) and its tributaries and that was formed by Glacial Lake Agassiz 9,000 to 13,000 years ago (Chapman et al. 1998; Fig. 1). The river valleys provide suitable woodpecker habitat because they support stands of mature trees, such as bur oak (Quercus macrocarpa), hackberry (Celtis occidentalis), American elm (Ulmus americana), basswood (Tilia americana), and green ash (Fraxinus pennsylvanica). Historical observations of pileated woodpecker occurred, and continue to occur regularly, along the Red River and its tributaries and in the Pembina Hills. More recent observations have occurred in the Turtle Mountains, in the Devils Lake area, and near the James, Missouri, and Sheyenne rivers.
|Figure 1. Geographical areas in North Dakota mentioned in the text, and location and frequency of pileated woodpecker sightings in North Dakota from 1900 through 1950.|
I describe the historical range of the pileated woodpecker in North Dakota and present previously unpublished information that documents the range expansion of the pileated woodpecker in eastern North Dakota. Several esteemed ornithologists failed to document the presence of the pileated woodpecker west of the Agassiz Lake Plain in the 1800's and early 1900's. Since the 1990's, however, the pileated woodpecker has been sighted as far west as Mandan, Morton County, on the Missouri River.