While wandering about Killdeer Plains Wildlife Area last Thursday, I heard the raucous kwerrs of a Red-headed Woodpecker coming from a patch of oaks. The calls continued from the same general area for some time, while I focused on sorting through a passel of sparrows along a nearby field's edge.
Red-headed Woodpecker granaries are more haphazard in design but serve the same purpose. Acorns collected by the birds are stuffed into tree crevices and fissures, into small cavities, and under bark. The purpose? Stocking in supplies for winter, the food to be withdrawn from the larder when times get tough.
At this time of year, when the acorn crop is ripe and the winter's cold winds are right around the corner, Red-headed Woodpeckers work double-time at provisioning their granaries. This woodpecker probably made one round trip about every five minutes or so, and likely spent a good chunk of his day at this task. By the time he's done, that old oak tree will probably have hundreds of acorns stuffed throughout its limbs. Its bank vault of acorns will serve the bird well when food becomes lean in the dead of winter.