First, the researchers recorded videos of woodpeckers’ heads in motion. To capture this rapid movement, the scientists needed special high-speed cameras. Each peck lasts only a fraction of a second!
Van Wassenbergh’s team recorded videos of six woodpeckers from three species and analyzed the footage. The researchers used a computer to track three points on each bird’s head: one on the skull and two on the beak. The scientists hypothesized that if the birds’ skulls had shock absorbers, the footage would show a “squishing” of the space between the skull and beak—like when a spring compresses. But that didn’t happen. Instead, the birds’ heads moved as one stiff unit, like a hammer.
Next, the team wanted to demonstrate why this adaptation would be helpful to the birds. Using computer models, the scientists simulated woodpecker skulls with and without shock absorbers. Then the researchers compared the force of the pecks. “The pecking performance was greatly reduced in the skull with a shock absorber,” says Maja Mielke, a biologist who worked on the study. With shock absorbers, says Mielke, “the poor birds would need to pound even harder to reach the same results.” For a woodpecker, having a shock-absorbing skull would simply be a waste of energy.