Woodpeckers, as their name suggests, peck on the wood of trees to look for or hide tasty treats, and to build nests. In addition to drilling holes, woodpeckers will knock their heads to send sound signals.
They can strike a tree at speeds up to 15 mph, which is enough force to create brain damage in most other birds, and certainly in our human brain. But due to a number of adaptations, woodpeckers thrive on this heavy hitting.
First the woodpeckers' skulls are incredibly strong, yet lightweight, due to a reinforcing meshwork of bony support struts. Their brains also sit snugly in the skull with very little cerebrospinal fluid meaning the brain won't bang around as the head moves back and forth.
Second the dense muscles in their neck and mouth contract just before impact, which transmits the impact past the brain and allows its whole body to help absorb the shock.
Third the tongue starts out on top of the mouth, passes through the right nostril, between the eyes, divides in two, arches over the top of the skull and around the back part of the skull passing on either side of the neck, coming forward through the lower mouth, and uniting into a single tongue with sticky barbs on the end which can extend up to 4" from the beak. The tongue is also thought to act as an additional buffer to the brain.
Fourth there are special cells at the tip of the bill that constantly replace the lost material, keeping the bill strong and sharp.
Fifth they close an inner eyelid a millisecond before a strike comes across the bill to prevent harm from flying debris and hold the eyeball in place.
Sixth is the adaptation in their feet. They have two toes that point forward and two that point backward that allow them to cling to tree trunks. Other backyard birds have three toes forward and one in back.
Seventh the woodpeckers’ pointed tail feathers are also especially strong and rigid, and their tail bones, lower vertebrae and the tail’s supporting muscles are very large in comparison to other birds. These modifications allow a woodpecker's tail to serve as a sturdy prop that supports its weight while clinging to trees. Some Wild Birds Unlimited Suet feeders have tail props to make it more comfortable for the birds to feed.
This behavior and many other woodpecker adaptations can be witnessed in your yard. Woodpeckers can easily be attracted to feeders filled with suet or nuts. Simply offer these foods and you can get an up close and personal look at some of the toughest guys in the neighborhood.