You've heard it since the day you were born - a plethora
of voices singing outside. Even in New York City, doves coo and falcons
screech while we go about our business. Have you listened? Heard it
in your mind and heart? Felt it deep in your gut? Ever wondered what's
really going on out there in the palo verdes, gardens, parks or palm
A bird song is a consistently
repeated pattern of tones. All other bird vocalizations are called calls.
Songs are heard in nesting season. Calls are heard year round. Birds
use both songs and calls for communication. For the most part, the boys
form the choir. Unlike our prattling species, a bird sings for a reason.
He lets others know where his kingdom is and issues no trespassing alerts.
He has a biological imperative to find a mate so love songs are in order.
Song also helps keep a monogamous pair together once the young make
their entrance. While most females do not develop as rich a voice as
their mates, cardinals are one exception. The female often sings as
well as her mate. They practice a form of duet, called antiphonal
singing. Sometimes the alternating, but dissimilar, songs of the
male and female Cardinal are so perfectly timed that our ears hear it
as one long avian aria.
Like all vocalizations, bird song is produced by syrinx,
a structure much like our voice box, located at the bottom of the windpipe.
But birds also produce sounds by using their tail, bill, wings, etc.
The Common Nighthawk flutters around at dusk and every now and then
utters a soft rasping peent... Then, in the checking a quick
downward dive, it allows the air to rush through its wings and makes
a sound you can imitate by blowing across the mouth of an empty jug.
Woodpeckers pound on trees, houses, cooler vents or anything that resonates
to attract a mate. While musical talent varies from species to species,
and from individual to individual, very few birds fail to make any sound
at all, be it a true song or a substitute sound.
Most birds break into full song when they have established
their home range. The song slacks off for the very short mating period,
often vigorously returning for nest building, egg laying and incubation.
When the young are being cared for, the singing diminishes. Unless the
pair lays a second clutch, singing stops by the time of the end of the
nestling period and the postnuptial molt. Among the birds that resume
singing after molting, the songs are far fewer in number, and may be
incomplete. Winter signals the end of bird song, with a few exceptions
like the Cardinal that pretty much sings the year round.
Ever seen a Curved-billed thrasher giving a concert from
atop an ocotillo? Many males attract attention by singing while perched
in a conspicuous spot. Often times the same bird advertises time and
time again from the same spot or spots. Some birds sing while flying.
Larks, bobolinks, buntings, and other small birds rise high in the air
over sunny fields or woodlands. They do not flap around, but seem to
float above the ground on trembling wings, all the while bursting out
in wildly sweet songs. The American Woodcock spirals upward on whistling
wings, then chippers away during an abrupt descending zigzag pattern.
The combination of a song and visual display increases the chances to
be noticed, and thereby mated.
Usually birds do not sing around their nests. When approaching
the nest, the male is inclined to be silent, or to use a muted voice.
There are reports of the male Black-headed Grosbeak singing while incubating
eggs and brooding young. His voice, though much softer than when away
from the nest, can still be heard for several hundred feet. Ornithologists
have located nests by listening for this song. A few male and female
birds sing a quiet, inward whisper song that can be heard no
more than 20 yards away. Female mockingbirds, American goldfinches,
Catbirds, Warbling vireos, Rose-breasted grosbeaks, and black-headed
grosbeaks contentedly whisper while sitting on eggs or young. Sometimes
whisper songs are heard when birds are alarmed or in rain, often in
the cover of trees or shrubs.
All singers have to learn their craft by practicing. Birds
often begin their vocal life with a subsong - a random subdued
warbling with recognizable call notes scattered throughout. The young
male songbird next adds some notes to the mix of warbling and call notes
that suggest his adult or primary song. The subsong grows more
varied, and by his first autumn, the young male is singing his rehearsal song. By the next spring, the bird has gradually dropped the random
warbling and call notes and is singing his adult primary song. The primary song is composed of repetitions of short motifs or sequences of notes in a definite pattern. Once established, the motifs
remain largely unchanged throughout the bird's life. Some birds, like
wood warblers, have secondary songs that are as complex as their primary
Birds generally sing more in the early morning and late
afternoon. The amount of light has more influence on the beginning and
cessation of singing than the time of day. Clouds delay the onset of
song in the morning and hasten its end in the evening. Not all birds
require the same amount of light and dark to stimulate singing, and
consequently, also depend on specific amounts of light and darkness
to trigger their songs. Total solar eclipses result in a dramatic demonstration
of the effects of light and dark upon bird song. As the world grows
darker, the diurnal birds ceases singing as they would at twilight.
Then the crepuscular birds, those that are active at dawn and twilight,
join in. As totality comes on, the nocturnal species add their voices
Finally, the concept of birds singing for the joy of it
can't be entirely ruled out. Here's how Thoreau saw it:
"Some birds are poets and sing all summer. I am
reminded of this while we rest in the shade and listen to a wood thrush
now, just before sunset... It is not so much the composition of the
strain, the tone that interests us - cool bars of melody from the atmosphere
of everlasting morning and evening. It is the quality of the sound,
not the sequence. In the pewee's note there is some sultriness, but
in the thrush's alone declares the immortal wealth and vigor that is
in the forest. Here is a bird in whose strain the story is told. Whenever
a man hears it, he is young and nature is in her spring; whenever he
hears it, there is a new world and one country, and the gates of heaven
are not shut against him."