An Avian Symphony

By Tina Mitchell

It’s spring morning, and I’m out with the dogs shortly after sunrise, heading to the low ridge to the east. It’s a peaceful time for us humans and canines. But once I shift my awareness, I can hear the air crackling with communications. “DEE-DEE-DEE.” (Mountain Chickadee) “CheeriLEE-cheerio cheeriLEE-cheerio.” (American Robin) A repeated dry hiccup-like sound. (Gray Flycatcher) “Zeedle-zeedle-ZEE-chay.” (Black-throated Gray Warbler) “Chup-chup-ZEEEEE (Spotted Towhee) Male songbirds of all species sing as if their lives depend on it. And, in a way, they do.

Beginning an hour or so before sunrise in spring and summer, this dawn chorus begins. But what are these songsters trying to convey? Some are announcing that they made it through the night. (“Hey, neighbors. I’m still here. Don’t try anything.”) Some might be hoping to lure in a female who might have arrived overnight. (“Hey, baby – new here? Check out this great piece of land I’ve staked out.”) Regardless of the message, singing is a key part of the avian breeding season. If you have American Robins in your neighborhood, they’ll probably be your first singers of the day. (Remember the adage “The early bird catches the worm?” That early bird of yore was, indeed, a robin.) Other species chime in as the light increases. By mid morning, the musical frenzy wanes considerably, although some species sing throughout the day. Another less intense round of singing kicks off as the sun begins to set. At our house, American Robins (cheeriLEE-cheerio, cheeriLEE-cheerio), Mourning Doves (oo-AH-ooooo-oo-oo), and Spotted Towhees (chup-chup-ZEEEEEE) broadcast the last songs of the day.

We humans use a larynx to produce sound. A bird, though, has a syrinx – a much more complex structure with multiple pairs of tiny muscles independently controlling two membranes. These dual membranes actually allow a bird to sing two notes simultaneously. In fact, one of the loveliest songs of the Colorado mountains is the Swainson’s Thrush’s ascending, double-noted duet with himself. The syrinx also lets a bird make sounds unlike anything a human can produce. When I first started learning to identify birds by ear, I marveled at the odd concoctions some folks used to try to capture the songs. CheeriLEE-cheerio, cheeriLEE-cheerio? No self-respecting American Robin would recognize that rendition. Zeedle-zeedle-ZEE-chay? Are you kidding me? A pretty far cry from what that Black-throated Gray Warbler really sounds like. Perhaps the award for the most bizarre mnemonic goes to the Warbling Vireo: If-I-SEE-it I-can-SEIZE-it and-I’ll-SQUEEZE-it ‘til-it-SQUIRTS. Seriously now, people … But these representations do reflect the rhythm and accents of a song and can help to link the song to the singer. Some songs, though, just can’t be captured via meager human tools: The downward tumbling whistles of a Canyon Wren, ricocheting off high rock walls; the inimitable but unmistakable bubbling, gurgling notes of a Western Meadowlark floating across a field.

As breeding season progresses and nestlings hatch, the singing begins to diminish as the parents hustle all day to find food for the begging youngsters. Here in central Colorado, the skies quiet down by mid-July. Birds continue to vocalize after that but typically use simpler call notes that help keep them in contact with others around them rather than defend territories or attract mates. But while spring and summer are the most tune-filled seasons, birds sing at other times too. In the fall you might hear a brief upsurge in songs. During this “fall recrudescence,” the sun shines at an angle similar to that found in early spring – and some birds think it’s time to crank up breeding activities again. Also at this time, the young that hatched in the summer try out their songs for the first time, sometimes with comical variations before they get it just right. On a warm late winter day, you might hear an occasional song too. At our place, the year-round-resident Black-capped Chickadees (HEY-sweetie), Mountain Chickadees (DEE-DEE-DEE), and White-breasted Nuthatches (yidididi) may jump the gun a bit. A few species – most notably for our area, the Townsend’s Solitaire – actually sing all winter to defend scarce sources of food. The Solitaire’s beautiful lilting song slicing through the cold winter air offers a reminder that spring will come, even when we’re locked in the bleak midwinter.

As the seasons rotate between the northern and southern hemispheres, at any time somewhere on the planet, birds are singing. This time of year, the avian symphony around us provides glorious “ear candy” from sunrise to sunset. All you have to do is kick back, close your eyes, open your ears, and let the music pour into your soul.

Tina Mitchell watches nature with her human and canine family from their perch in the piñon/juniper habitat of western Fremont County. When she needs to pay the bills, she shows up as a research psychologist on the University of Colorado Anschutz Medical Campus in Aurora.