Woodpeckers are fascinating creatures. They hammer their bills into wood with force so ferocious that it would lead to concussion in any animal. But woodpeckers are equipped with excellent natural shock absorbers that protect their brains against damage caused by rapid and repeated powerful blows, such as a tightly packed brain that prevents it from sloshing around the skull, which itself is composed of compressible sponge-like bone to absorb the energy of the impact, as well as an elongated tongue-bone that wraps around the skull cushioning the brain as it deaccelerates at up to a thousand g. Most woodpecker species peck at tree trunks to build nests, except the acorn woodpecker, that drill holes to store food.

An acorn woodpecker hoarding acorns for winter on a utility pole. Photo: Ingrid Taylar/Flickr