The clock reads 5:35 AM. My wake-up call trills with robust enthusiasm two feet from the bedroom window. A House Wren, only recently returned from South America, has chosen for its own a nest-gourd hanging under the awning there.
Awake now, I recognize another dozen dawn choristers. Why are they singing? Why more in spring than in other seasons? And why do they sing with greater gusto at dawn than at any other time?
Here’s a clue: It has nothing to do with happiness. For birds, song is communication, and they talk only about two topics: love and war. At dawn, most females lay their egg of the day; and at dawn, sound travels well in the quiet. So, yes, it’s about love (meaning, in avian terms, reproduction) and war (staking out and maintaining territory). And part of love and war is staying in touch. In fact, the Red-eyed Vireo seems to say, “Here I am,” then ask, “Where are you?” Paired Canada Geese talk as they fly, her honking higher pitched than his, assuring each of the other’s well being.
Bird songs vary as much as birds themselves. Eastern Bluebirds burble soothing lullabies. Mourning Doves indeed coo mournfully. Eastern Screech-owls emit a quavering whistle that can strike fear among the brave. Yellow-breasted Chats jumble their song so much that I chuckle. Great-blue Herons squawk as annoyingly as fingernails on chalkboards. And Bald Eagles.
But birds have calls as well as songs—a chip, chirr, or chatter—also about love and war. Chips warn a nesting mate there’s trouble nearby or an intruder that he’s trespassed. Calls lure fledglings from nests. Sometimes calls rally other species, ganging up on predators like snakes, cats, or roosting owls.
For me, though, song and call serve another purpose. They catch my attention, sometimes because I know—or because I don’t know—what I’ll enjoy seeing when I locate the source. Last night, out for our evening walk, I heard a Common Nighthawk. I doubt I would have looked straight overhead without his prompting me of his presence
Sometimes, however, finding the source drives me silly. At every opportunity, I listen and look for a Kentucky Warbler. When I hear him, I eye the undergrowth, straining for a glimpse of this stealthy woodland bird. Sometimes I actually track the sound to a bird, only to find not the warbler, but a Carolina Wren whose call closely resembles that of the warbler.
So it goes with some bird songs. Scarlet Tanagers are said to sing like American Robins with a sore throat; Summer Tanagers, like robins that had voice lessons. Hm? On the other hand, a Wood Thrush sings an unmistakable flute-like duet with itself, the Chopin of avian choristers.
How do we learn who sings what? For years, we could only listen, then track the source, one bird at a time. Now, phone apps include bird songs that allow us to listen repeatedly, anytime, anyplace. Or online at Cornell University’s Lab or Ornithology site, where we can search for a species to learn its song