Written by Elizabeth Pennisi
Drive a nail into a tree, and you will stumble. So why isn’t the same thing happening to sharp woodpecker beaks? Scientists say they finally have the answer.
In a new study, researchers captured high-speed videos of two black woodpeckers (Dryocubus MartiusClicking away hardwood trunks in zoos and analyzing them frame by frame to see how the head and beak move with each click. The bird’s secret: The ability to independently move their upper and lower beaks, The team reported this week at the virtual annual meeting of the Society for Integrative and Comparative Biology.
Once the tip of the woodpecker’s beak hits the wood, the bird’s head turns slightly to the side, raising the top of the beak and twisting it slightly in the other direction, as videos reveal. This pull opens the beak slightly and creates a clear space between the tip of the beak and the wood at the bottom of the perforated hole, so that the bird can then withdraw its beak with ease.
Until now, scientists believe that woodpecker bills will need to be rigidly attached to the skull to successfully pry into wood to find insect prey. But in reality, the flexibility of the bill at these joints ensures that the « rat-a-tat-tat » bird’s signature does not stop at the « rat. »
