The singing season has arrived. Hallelujah!
This morning I heard a Red-bellied Woodpecker” brupping” in the distance, and a Pine Warbler singing a quickly trilled counterpoint to the open noted, more deliberate trill of the junco. The cardinals have been “cheer-cheer-cheering”, the chickadees “fee-bee fee-baying,” and the doves” oo-wah-coo-coo-cooing” for a couple of weeks, all with increasing frequency and enthusiasm.
White-throated Sparrows are practicing for the big event scheduled when they get back to their breeding grounds, and robins start every morning “cheerily-cheeruping.” Despite my feeble attempts to assign “English” translations to the sounds I hear, the advent of the avian chorus is one of the highlights of my year.
The anatomy of bird song is a marvel. Birds produce sound in their syrinx, an organ that works like the human vocal cords, only better. Located at the base of the trachea (not at the top, as in humans), the syrinx is a bony structure surrounded by an air sac. By varying the tension on the supporting membranes, changing the intensity of the air pressure passing through them, and the amount of air in the air sac, birds create the notes we hear as a sign of spring in the singing season.
But recent research has shown that it is not just the syrinx that is responsible for the piercing scream of a Blue Jay or the haunting notes of a Wood Thrush. Birds don’t just push air out through the syrinx and call it a song. Like humans, they change the shape of their vocal tract (including the throat, mouth cavity, pharynx cavity, trachea and esophagus) during the course of a single exhalation, changing the pitch, volume, intensity, and quality of their song in the process. The air sac is also capable of producing sound, which accounts for the two separate “voices” sometimes seen on sonagrams of a single bird (sonagrams are electronically separated and digitally written representations of sound across time, looking something like the test strip from a seismograph or lie detector).
Still, while the physiological details are fascinating, it is the philosophical ones that calm our weary souls each springtime. My husband (who has been seriously overworked in an almost literal 24/7 sort of way for the past several months, and has taken very little time for life’s little pleasures) called me on his cell phone last week. “You can probably get me to go birding this weekend,” he said. “I am parked at the light at Church Road and Eayrestown, and I just heard a Meadowlark sing.”
Life is good.
Barbara R. Jones
Former Wild Bird Center Owner
Tabernacle, NJ
For Additional Information:
Erlich, Paul R., David Doblin and Darryl Wheye, The Birder’s Handbook, A Field Guide to the Natural History of North American Birds, Simon & Schuster/Fireside Books, 1988.
Kroodsma, Don, The Singing Life of Birds, Houghton Mifflin, 2005 (also at www.thesinginglifeofbirds.com)
Rothenberg, David, Why Birds Sing, A Journey into the Mystery of Bird Song, Basic Books, 2005. (also at www.whybirdssing.com)
Carey, Bjorn, How Songbirds Change Tune, Live Science, www.LiveScience.com/animalworld/060327_bird_singing_html
www.bna.birds.cornell.edu/bna/demo/account/yellow_warbler/sounds.html
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