Pileated Woodpeckers, which are about the size of small Crows, are the largest woodpeckers in North America. They occur in hardwood forests throughout the eastern and northwestern US, and southern Canada. Their loud, piping call (a short series of high-pitched, hornlike "YIPs") rings throughout their forest territories in late winter and spring. Unlike other woodpeckers, which make circular holes in trees, Pileated Woodpeckers excavate rectangular or oblong holes as entrances to their nest cavities, often leaving a substantial pile of wood chips on the ground at the base of the tree.