Listen To Spectacular Predawn Chorus

By Scott Shalaway
IF YOU HAVE ever wondered why birders start their days well before dawn, it’s because that’s when birds begin their day.

Last summer I reported that, on July 24-26, I rose at 4 a.m. to monitor the midsummer dawn chorus. I recorded the first bird song at 5:53 a.m., a cardinal, and subjectively concluded that the chorus peaked from 5:34 to 6:07, eight minutes before the sun rose at 6:15. Since then, I’ve been anxious to repeat the experiment during the nesting season. As expected, the spring concert began earlier.

On May 9-10, I again rose at 4 a.m. and began listening intently. According to the U.S. Naval Observatory, astronomical twilight began at 4:27 a.m. That’s when the sun is 18 degrees below the horizon and begins to illuminate the eastern sky.

At 4:58, I heard the first unidentifiable, distant voices in woods. At 5:05, a neighbor’s rooster crowed. The first cardinal sang at 5:06, followed by a Song Sparrow at 5:11. The birds had begun to awaken.

At 5:15, I noted that several cardinals were singing every few seconds. They were soon joined by Great-crested Flycatchers (5:17), robins and Wood Thrushes (5:18) and Scarlet Tanagers (5:26). At this point, I described the chorus as, “continuous, just brief moments between songs.”

More species quickly chimed in: Gray Catbird (5:28), Eastern Towhee (5:32), Eastern Phoebe (5:33), Carolina Chickadee (5:34), Carolina Wren (5:35) and Mourning Dove (5:40). At 5:44, the horizon was clearly defined, marking the onset of civil twilight.

At 5:47, a turkey gobbled, and I wrote, “It’s now hard to pick out individual songs. The birds are all singing on top of each other.”

I was hearing the crescendo of the morning chorus. The frenzied cacophony would continue for 18 minutes as the following birds joined in: House Wren (5:51), Tennessee Warbler (5:52, and at this moment, the day’s first hummingbird arrived for breakfast), Yellow Warbler (5:54), Brown-headed Cowbird (5:55), Yellow-billed Cuckoo (5:56),Tufted Titmouse and Blue-winged Warbler (6:02), Downy Woodpecker (6:03), Eastern Bluebird (6:04) and Blue-gray Gnatcatcher (6:05).

From 5:47 to 6:05, every bird listed so far sang repeatedly and insistently. Cardinals, towhees, phoebes and Carolina Wrens sang loudest. At any given moment, I could hear three or four individuals of these dominant species. I struggled to ignore them so I could hear the others. At 6:06, eight minutes before sunrise, the intensity of the morning chorus began to fade. More voices were yet to come, but picking out individual songs began to get easier.

At 6:07, I heard a Chipping Sparrow, a crow, a Common Yellowthroat and, at 6:11, a White-eyed Vireo. The sun rose at 6:14 and eventually the sleepy-heads joined in: Baltimore Oriole (6:17), indigo Bunting (6:25), Field Sparrow (6:28) and Rose-breasted Grosbeak (6:34). Most birds continue to sing until midmorning, but the chorus peaks early.

Though human ears might have difficulty identifying the individual members of a chorus consisting of dozens of singers, the birds do not. Each responds only to its own species’ songs. Males interpret another male’s song as a territorial keep-out signal, while females hear the same song as an invitation to bond and mate.

And the “noise” created during the peak of the predawn chorus is no doubt as confusing to predators as it is to birders. Screech Owls, for example, which actively hunt for song birds at dawn and dusk, surely have trouble locking in on the sound of one potential prey item when many are singing at once.

Birders, especially beginners, assume that getting in the field at dawn is necessary for the best experience. As I found last summer and again last week, however, the peak of the morning chorus is already over at dawn. To hear the springtime, limited engagement of the most spectacular choir on the planet, get to the woods at least an hour before dawn.

And even if you can’t identify all the bird songs you hear, anyone can recognize that there are many voices in the choir. With time and experience, you’ll recognize the orioles, towhees, and robins in the dawn chorus as easily as the flutes and violins in an orchestra. –Pittsburgh Post Gazette