Woodpeckers do peck wood
One of the first columns I wrote was on woodpeckers. These handsome, charismatic, industrious birds are a favorite of mine. There are 20 species throughout the United States, and in southern Illinois you can find eight of them, ranging from the mighty crow-sized pileated to the diminutive downy woodpecker.
But no matter the size, one thing all woodpeckers do well is peck wood. They do so to look for food, stripping off bark and hunting for grubs, they drum on wood to attract mates, and they excavate nest cavities with their chisel-like bills.
A few of them, especially the northern flicker, will also use their barbed tongues to flick up ants from the ground. Look for this fairly large birds with a barred rufous back and black-spotted breast on your lawn, especially if you have lots of ants!
Do you remember the word zygodactyl? It means having two toes facing forward and two toes facing backward. Along with their stiff tails, this allows woodpeckers to expertly climb and lean backwards along tree trunks. They can just as easily climb up, down, and from side to side. As a matter of fact, if you are trying to watch a woodpecker, it sometimes seems to disappear before you ever get your binoculars on it.
Sapsuckers, a special kind of woodpecker, seem especially adept at staying out of sight. These woodpeckers breed just to the north of us, and only visit southern Illinois in the winter months. They are much quieter than our local brethren, and tap very softly.
They also have a unique feeding technique. They will bore small holes in lines or circles around tree trunks and limbs, causing sap to accumulate in these holes. That, in turn, attracts bees and other insects to the sweet sap. Some of the insects invariably get stuck, and when the Yellow-bellied Sapsucker makes its daily rounds of its sap wells, it feeds on the mired insects.
In my first column, I reported that researchers have found that a woodpecker can slam its bill against a tree at a speed of 20 feet per second, with a corresponding deceleration of 1000 times the force of gravity (g's). Considering humans usually suffer concussive trauma at 60 g's, how do woodpecker brains withstand this massive g-force?
These scientists attributed the woodpecker's wellbeing to three factors: a specially structured beak, which absorbs some of the impact; a unique hyoid bone attached to the base of the bill that wraps around the skull and performs like a seatbelt to absorb shock; and, finally, that portions of the skull are composed of dense, spongy bone which acts like a bike helmet.
Now comes word from a team of biologists at the University of Antwerp who used high-speed cameras to refute the shock-absorbing idea, that the real reason woodpeckers can handle these concussive shocks is the very small size of their brains - about 700 times tinier than ours. Akin to a fly bashing its head into a window pane without injury.
If you'd like to attract more woodpeckers to your yard, hang up a suet feeder. If you'd like to see them in the wild, visit an area with lots of trees - sites like Giant City State Park and Oakwood Bottoms boast all the Illinois woodpeckers and are outstanding natural areas. See how many species of woodpecker you can find in southern Illinois this month!
Current regional sightings
This is the time of year to search flooded fields and the backwaters of the Mississippi River for vagrant waders like white-faced ibis, wood stork and reddish egret. It's also the time of year when shorebirds begin their south-bound migration to wintering grounds along the Gulf Coast and sunny beaches in Argentina. A solitary sandpiper has already been spotted at the Carbondale Reservoir.
• Carbondale is my home town, where I started birding over 50 years ago. I spent an exciting 16 years as a bird guide, and have penned bird-finding books for Arizona, California, and Illinois counties. I currently reside in Arizona, where you can reach me at HenryDetwiler@earthlink.net.