When the class topic is woodpeckers, the No. 1 question students ask is how these birds are able to slam their heads against a tree without damaging their brains.
The answer, explains Amy Loving, education coordinator at Davenport’s Nahant Marsh Education Center, is that the woodpecker brain has evolved to withstand this punishment.
The brains are small and oriented so that more than 99 percent of the energy generated in pecking is distributed throughout the bird’s body, with only a small fraction going to the brain.
In addition, there is little fluid surrounding the brain, preventing it from sloshing around inside the skull.
Finally, each hit is of very short duration, as opposed to in human football, for example, where the duration is long by comparison.
But the questions about woodpeckers don’t end there.
Both Loving and Steve Hager, professor of biology at Augustana College, Rock Island, have found that woodpeckers generate lots of questions. Today we share some of those questions and answers.
Q: What kinds of woodpeckers do we have in the Quad-Cities?
A: Downy and red-bellied are tied for first place in terms of which you’re likely to see at a backyard feeder, Hager said.
Then, in descending order, common Q-C area woodpeckers are the hairy, the red-headed and the northern flicker, although you won't see a flicker at your feeder because they are ground-feeders, Hager said.
Q: How can I get woodpeckers to come to my feeder?
A: Put out suet cakes and black oil sunflower seeds, Hager said. Woodpeckers are omnivores, feeding on insects as well as nuts, fleshy fruits and sap.
Q: When woodpeckers make that drumming sound, what are they doing?
A: They could be doing one of three things — communicating with other birds, either in staking out a territory or trying to attract a mate; digging into a tree to make a nest cavity, or drilling through bark to get at bugs or larvae underneath.
Heavy woodpecker activity is a sure sign of emerald ash borer infestation, for example, because there are a lot of larvae to eat in an infested tree.
Q: Does all drumming sound alike?
A: No. Each species has a pattern that is unique in the number of beats in the roll, the length of the roll, the length of the gap between rolls and the cadence.
To do their drumming, woodpeckers choose a surface that resonates, such as a hollow tree or man-made structures such as gutters and downpipes.
Because they communicate by drumming, not singing per se, they are not considered a songbird, Hager said.
Q: What other woodpecker characteristics do either of you find amazing?
A: For Loving, it is the tongues, that can be as long as a bird's body — yes! — and are specialized, depending on the bird.
Because a woodpecker typically probes crevices that prevent people from seeing the tongue, its length is one of the best-kept secrets of bird lore, according to the website allaboutbirds.org.
And most amazing: When a woodpecker with a long tongue retracts it, he/she will store it by wrapping it around its skull!
In addition, woodpeckers' roles as parents are different from other birds, in that they co-parent, and the male takes the night shift, Loving said.
When Hager thinks of woodpeckers, he is mindful of all the threats they face in their fight for survival.
As wooded areas are cleared for development, their habitat disappears. Invasive bird species, particularly the European starling, compete with woodpeckers for nest cavities.
Add to that the reality of urban ecology such as noise, pollution, cats and obstructions (buildings, power lines), and woodpeckers — all birds, really — face many challenges, Hager said.