Hard-headed and hungry: How woodpeckers safely find their food
Hitting your head against a tree a thousand times a day sounds like a way to do severe physical damage to yourself.
If you’re a woodpecker, it’s a great way to get a meal.
A head structure designed for a hard-hitting way of finding food is one of several characteristics that make woodpeckers unique members of this area’s outdoors world. Depending on the time of year, Missouri is home to seven species of woodpeckers. Some are year-round residents of Missouri, but most woodpeckers are seen more frequently in winter, primarily because of a lack of foliage.
Woodpeckers are best known for their trait that gave them their name – pecking on trees to find grubs and insects located in the wood and also to establish territory. These pecks aren’t gentle taps. It’s estimated the force of a woodpecker’s peck is equivalent to a human hitting his head against a hard surface at a speed of 16 mph. When you consider a woodpecker may deliver up to 1,000 pecks per day, it sounds extremely painful and – from a head trauma perspective – quite dangerous.
However, a woodpecker’s head is built to take this type of pounding. In humans, injury often results when a jarring blow to the head causes brain movement within the skull. That doesn’t happen to a woodpecker, though, because a woodpecker’s brain is squeezed tightly into its skull. This snug fit prevents the brain from being jarred while the bird is hammering on a tree. A woodpecker’s skull is also thick and spongy; traits which help the bird absorb the shock of repeated pounding.
This has nothing to do with head protection, but another characteristic that helps woodpeckers get food is a long tongue supported by bones. When not in use, this tongue wraps over the top of the skull (underneath the skin). The bristle tip of the tongue helps spear insects lodged in the cracks and crevices of trees.
Unlike most birds, a woodpecker’s foot has two toes pointing forward and two pointing backward. This characteristic – called zygodactyl feet – allows them to firmly grip vertical surfaces and also helps them maneuver up and down trees. Zygodactyl feet are a trait woodpeckers share with their close relatives, toucans. Both belong to the bird order Piciformes. (Within this group, woodpeckers belong to the bird family Picidae.)
Woodpeckers aren’t the only ones that benefit from the wood-boring adaptations. Studies have shown that a single woodpecker can eat up to 13,500 beetle larvae in a year. This beetle consumption has huge benefits for humans since woodpecker’s diet contains a number of species that can cause problems for trees.
If you want to see woodpeckers, walk through any wooded area and keep your eyes and ears open. Pay particular attention to dead or dying “snag” trees. These trees can be good woodpecker areas because they provide food and, for some species, nesting habitat.
More information about woodpeckers can be found at the Missouri Department of Conservation’s website, mdc.mo.gov.
Francis Skalicky is the media specialist for the Missouri Department of Conservation’s Southwest Region. For more information about conservation issues, call 417-895-6880.