Friday, May 8, 2015

Red-headed Woodpecker

Erika and I usually find Red-headed Woodpeckers at the Nerstrand Big Woods State Park, as we did last Tuesday. Numbers, however, vary from year to year, and we do not list this species on every visit. Populations are apparently dependent on the abundance of the local acorn crop, which also varies annually. The woodpeckers collect and store acorns during the fall.

Birders have long been aware of Red-headed Woodpecker population fluctuations. The destruction of American Beech forests and the disappearance of the Rocky Mountain Grasshopper (upon which the woodpeckers fed in the Midwest), both events nearly brought Red-headed Woodpeckers to extinction.  Populations rebounded, however, with the extinction of the American Chestnut and the dead trees left by Dutch Elm Disease—both plagues leaving plenty of dead trees in which the woodpecker could breed. As these tree carcasses are cleaned out, woodpecker populations are again falling. A tendency to be hit by cars and unsuccessful competition for nest sites with starlings have not aided woodpecker recovery (Frei et al 2015). In many states and provinces, Red-headed Woodpeckers are listed as Threatened Species; Eckert considers these woodpeckers to be uncommon in Minnesota.

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