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The rustle of dry leaves though a gray forest, the honking of geese sounding across a leaden sky threatening snow, the tinkling of thin ice warming on a river’s edge. Late autumn at its best. Welcome to The Nature of Phenology where we share the cycles and seasons of the outdoors. I’m your host, Hazel Stark.
Once the deciduous trees have dropped all their leaves, when even the beeches and oaks have finally let go of the papery husks of their formerly lush green leaves, a certain stillness covers the landscape. The wind suddenly slithers through the forest with ease, sounding somewhat more maniacal than it did when cushioned by leaves during the summer. We start to notice the white trunks of the paper birch trees suddenly on display and providing a welcome depth of shade on the forest landscape, just vacated of the rich reds, oranges, yellows, and greens of the fall. We’re reminded that winter is here and with the reduction of daylight hours and the color green, many birds have left. We will still hear the occasional chortle of a raven pair, the lonesome hoot of a barred owl on a clear night, and the piercing shout of a blue jay, but that monkey-like chatter of a pileated woodpecker is like no other winter sound. That group of head-pounding, snag-loving year-round birds is our focus for this week.
Woodpeckers: Most people know them due to their noisy evidence. Here’s the common sound of a pileated woodpecker, which should sound familiar as it is the theme music for this program. [WOODPECKER SOUND HERE] Whether chattering loudly, slamming on a telephone box in the spring, or pounding into a hollow tree in hopes of finding some bugs to eat, woodpeckers are pretty charismatic. There are three types we commonly see in Maine: pileated woodpeckers are the largest—the only woodpecker the size of a crow (see featured photo above); hairy woodpeckers are more mid-sized, and downy woodpeckers are a bit smaller. People often struggle with discerning the difference between a hairy and a downy woodpecker, so here are two simple tips: Hairy woodpeckers have a longer beak, about the same length as their head, and spend more time on trunks of trees while downy woodpeckers have a beak about half the length of their head and spend more time on branches.
But what I find especially fascinating about woodpeckers is why they don’t get concussions from all their head-banging. There are a number of logical factors at play: woodpecker brains fit snugly in their skulls so the brain itself doesn’t go careening in every direction under impact, bruising itself against the skull wall like human brains do. They are also much smaller animals, so the matter of scale comes into play when considering why they don’t get concussions—picture throwing a ball of paper and a ball of lead against a tree. Also, woodpeckers are simply built differently, with their brains surrounded by web-like bones to diffuse the impact and situated at a different angle in their skulls than ours are. There are many answers to this seemingly simple question of how woodpeckers avoid head injuries, but my favorite rationale is that their tongues serve as an extra cushion during impact. Woodpeckers have long tongues that enable them to reach into tree cavities in search of food, but obviously they don’t hammer at wood with their tongues sticking out. They tuck their tongues along the bottom of their brains during their carpentry adventures, providing additional impact absorption potential.
So this week you can try to find a woodpecker, figure out what species it is, and watch it for as long as you can keep an eye on it. Can you picture its tongue in there, providing a perfect cushion for its fragile little brain?
You can find a link to the full transcript of this show as well as references, contact information, and accompanying photos by visiting archives.weru.org. You can also listen to or download our features or subscribe to podcasts. Theme music was by a pileated woodpecker, made available by the US Fish and Wildlife Service. Thanks for listening and please join us next week for another dive into The Nature of Phenology.
Eaton, J. (2006, November 21). Do woodpeckers get headaches? If not, why not? Retrieved October 22, 2018, from http://www.berkeleydailyplanet.com/issue/2006-11-21/article/25695?headline=Do-Woodpeckers-Get-Headaches-If-Not-Why-Not—By-Joe-Eaton-Special-to-the-Planet
Stark, H. (2016, March 06). Woodpecker Tongues Help Do What? Retrieved October 22, 2018, from https://partridgepineandpeavey.wordpress.com/2015/01/26/woodpecker-tongues-help-do-what/