Those who understand nothing about tennis are always amazed when they watch a match and discover that tennis players “grunt” while playing; and not surprisingly: they do it every time they hit the ball. Anyone who knows tennis knows that it is not a coincidence, but a method to synchronize breathing with body movements, and hit the ball more forcefully.
Well, woodpeckers also use the same technique: a study published in Journal of Experimental Biology demonstrates that the woodpecker moves its beak like a “hammer”, and that these birds also use grunting to amplify the power of the blow.
The research. The peaks analyzed in the study are eight specimens of Dryobates pubescensAmerica’s smallest woodpeckers, who were captured and “tagged” so they could be recorded drilling into pieces of wood. The team recorded a series of videos at very high resolution frameratewhich allowed us to analyze the animals’ movements in great detail, and also measured the electrical signals emitted by their muscles and the air pressure in their respiratory system. In this way, it was possible to identify which muscles are most involved in the “hammering”, and also the rhythm and frequency of breathing of the peaks during the act.
Like a hammer. As for muscles, the discovery is that woodpeckers contract a lot of them before drilling into a tree, so as to maximize the rigidity of their body: in simpler words, they transform into real hammers. The flexor muscles of the hips and the front muscles of the neck are essential: in addition to contributing to the stiffening of the peaks, they also produce the forward thrust needed to attack the tree.
breathe and charge. Even more interesting, though, is the way woodpeckers breathe when they hammer. They do it in a similar way to tennis players: with each blow to the trunk they exhale, and inhale when they pull back to load the next one. All of this happens at incredible speeds: Woodpeckers can hit a piece of wood up to 13 times per second, and the breaths they take between each strike last 40 milliseconds.
Are all woodpeckers tennis players? The only problem is that, unlike tennis players, it is impossible to hear the grunts of the woodpeckers as they hammer: the sound of the blows on the wood drowns them out. But the similarity between the two techniques is undeniable: now the team that conducted the study wants to verify what variations there are between different species of woodpeckers, to understand among other things if they are all “tennis players”.
