If you're an early riser and enjoy the outdoors, here's a way to enjoy one of nature’s special moments: Take your first cup of coffee outside, be still for a few moments and listen. It's the best time of day to hear the birds.
"Right around dawn is the optimum time to hear the chorus," said Greg Budney, curator for Collections Development at the Macaulay Library at the Cornell Lab of Ornithology at Cornell University. The members of the choir are numerous species of songbirds, each vigorously singing one chord after another.
To the untrained human ear, the singing may be a cacophony of sounds. But, to an ornithologist or another bird, the choral explosion is a harmony of music that is much more than the rise, fall and rhythm of notes and an amazing repertoire of joyous individual songs to welcome another sunrise. There is, Budney said, a reason behind the ritual.
"They're teeing up for the day," he said, pointing out that the early morning vocalists are mostly the males, with females occasionally joining in. "They're staking out their territory," he said. The males are warning off rival males or even pairs of other birds.
"But, even though it's the males you are likely hearing, it's the females who drive the system," Budney said. "They're listening and trying to figure out which male is the most fit, and therefore offers the best genes toward the survival of offspring. They'll choose a mate on how he sings."
The males look for a strategic perch to belt out their best stuff, Budney said. As you listen, notice where the sound is coming from, Budney said. "Often, it will be from high in the habitat so the birds can broadcast their song more efficiently," he said. High places, he pointed out, have fewer obstructions than lower ones and allow the birds to broadcast their song as far as possible. "The acoustic communication in birds is quite sophisticated, and they are very intelligent about the way they do this," he said. If you're lucky enough to be able to see the birds as they sing, watch carefully and you'll notice another fascinating part of the morning ritual. "The males will use the same perch over and over again," Budney added.
Regional cover songs
If you're an experienced birder and live in a northern city, such as Boston, you likely can pick out the song of the ubiquitous cardinal (Cardinalis cardinalis). But, if you're in a southern city, such as Charleston or Savannah and know your birds, you're probably thinking that the cardinal in that audio doesn't sound like the cardinals in your garden. And, Budney said, you'd be exactly right.
Like humans, birds have dialects, he said. So, just as a Bostonian would pronounce "harbor" differently than a Charlestonian, the same species of birds in different parts of the country have developed different variations of the same song. Song sparrows (Melospiza melodia) are another good example of birds with regional dialects, Budney said. "If you were to travel across the United States, you would hear song sparrows with dramatically different songs." Listen to the differences between a California sparrow, a Georgia sparrow and a Minnesota sparrow.
The chorus dies down as the sun starts rising because the birds, both male and female, begin moving around to forage. That doesn't mean the singing stops, but the purpose of the singing changes from a territorial purpose to courtship and becomes less vigorous than it was at dawn, explained Budney.
Learning to sing
The eastern bluebird is an Oscine singer, and that means that it must learn from its parent what kind of song to sing. (Photo: Ken Thomas [public domain]/Wikimedia Commons)
Another interesting aspect of bird songs, Budney pointed out, is that how birds learn to sing is dramatically different between two main groups of birds, the Oscine and the suboscine. Birds in the Oscine group have to learn their songs from their father or a neighbor. Budney calls the birds in this group the "true songbirds" and said they include familiar backyard birds such as robins, cardinals, grosbeaks and wrens. "Birds in the suboscine, however, are genetically hardwired as to the song they will sing," Budney said. "Researchers have raised suboscines in acoustic isolation without hearing the song of their species and, despite this, they still sing the correct song," Budney said.
The eastern bluebird (Sialia sialis) is an example of a bird in the Oscine group, Budney said. They are early morning singers, but as the season progresses, the rate of their singing decreases as the parents raise their young. "After the clutch hatches, the male starts again," Budney said. "The young have to learn their songs because the songs are not genetically acquired."
No matter where you live, you can enjoy the singing of America's approximately 400 species of songbirds. "Every region has its own sound," Budney said. In the Plains states, for example, he pointed out that the songs of grassland sparrows propagate effectively over the open habitat. These songs include the rich buzzy sequences of the Savannah sparrow (Passerculus sandwichensis) and the song of the chestnut-collared longspur (Calcarius ornatus).
The call vs. the song
As you listen to birds during the day, it's important to know that sometimes when you hear the birds you are hearing a "call" rather than a "song," Budney said. The difference is that songs are generally used for one of two reasons: either to stake out territory or for courtship. Calls may be to warn of a predator, such as a hawk or a cat, Budney said, so when birds see danger, they will give out an alarm call. For example, he said a cardinal will give out an alarm call that is a sharp chip note. Robins (Turdus migratorius) will give a tut-tut-tut when mildly alarmed. Birds give a variety of calls from parent to their young, Budney added, such as contact calls when they are foraging for food.
Some birds — chickadees, for example — also use calls to keep social units together as they search for scarce and limited food during the winter. In cold months, black-capped chickadee family groups (Poecile carolinensis) converge in the way they deliver the chick-a-dee-dee call to make sure another chickadee doesn't join their group. "Think of them as passwords!" Budney said. "They know who is in the family and who is not and can identify an interloper because he or she doesn't know the key to the proper 'pronunciation' of a call."
Each species has its own distinctive song, Budney said. Blackcap chickadees (Poecile atricapillus) sing fee-bee whereas the Carolina chickadee's (Poecile carolinensis) song is fee-bay.
Developing an ear for the birds' tunes
If you're not an early riser and missed the morning serenade, you have one more chance for a front row seat to the next best thing: the birds' evening song. The chorus will strike up again just before dusk, Budney said. The good night songs can be similar to the morning versions, but also can vary, he added.
As an example, he cited the thrushes, adding that the evening is the best time to record these birds. "Their morning song is frenetic and delivered very quickly," he said. "The evening chorus is much smoother and less frenetic. Why? That's a mystery yet to be solved."
What's not a mystery, he continued, is that, no matter where you live, listening to the sounds of birds is a way to engage in the lives of these compelling creatures. They live their lives in parallel with ours, and it's fascinating to stop and listen to them.
In time, even though the repertoire is substantial, you can identify individual bird sounds. Budney suggests learning a few at a time, starting with the songs of the most commonly seen birds in your area or the songs you find easiest to remember. Once you feel confident identifying those, then you can begin identifying songs that are less familiar. Before long, you may become so familiar with different songs that you’ll know who is singing and how many voices are in the choir.
To better learn (and hear) about song birds, Budney recommends three books by Donald Kroodsma. Each is written for the lay person. They are:
The first book is "The Singing Life of Birds: The Art and Science of Listening to Birdsong," and it is available in hardcover, paperback and Kindle editions. This book explains things like the process birds go through in singing and why they choose a particular song. There is a CD in the back of the book that includes all of the bird songs the author describes in the book.
The second and third books are more of a set. "The Backyard Birdsong Guide: Eastern and Central North America" and "The Backyard Birdsong Guide: Western North America." These regional editions are interactive handbooks of birds and their songs for beginning bird-watchers. A touch-button electronic module allows readers to access common vocalizations in each volume.
However, Budney said, there's no need to only listen on the sidelines when it comes to bird sounds. Anyone can contribute to the study of avian communication research by making recordings and submitting them to the Macaulay Library, which already has nearly 200,000 audio recordings of birds and other animals. There are many sounds, even of relatively common species, that have yet to be recorded well. If you're interested, the Cornell Lab of Ornithology offers an annual workshop on how to record the sounds of birds and other wildlife.