Planning for future
The woodpeckers harvest acorns directly from oak trees and are famous for their habit of storing nuts in individually drilled holes in one or more storage trees. These are known as granaries and can have upwards of 50,000 nuts stored in them. The birds drill the holes primarily in the winter, in the thick bark of dead limbs where the drilling does no harm to a living tree. Each year they reuse old holes and add some new ones. The acorns are wedged so tightly in their holes that they’re very difficult for other animals to remove. After they’ve been stored for a while, the fit becomes looser as the acorn dries out—group members periodically check their stored acorns and move the loose ones to smaller holes. (Source: http://goo.gl/5wcs9n)
