It won’t be long before the first robins show up. Those are the dumb ones. The smart robins stay down in Missouri an extra few weeks. The overriding reason birds sing at dawn is to stake out their territory. They are saying “I made it through the night, and I’m still here”. At dawn, the air is generally calmer and there are fewer distracting sounds. Sound carries better in the cool, dense, still air. It has been shown that a bird song in the wee morning hours is 20 times more effective than the same song at noon. One hour before sunrise is prime time for bird singing.
Bird chorus is most prominent at dawn. The singing starts at different times for different species of birds. We’ve all heard robins sing at three o’clock or four o’clock in the morning. Biologists believe that the robin knows that it has a better chance of being heard when there is little competition around. Nightingales and wrens follow the same pattern.
Bird singing is louder and more frequent in the mating season. Birds are attempting to attract a mate. Females tend to lay eggs in the morning. It stands to reason that males will try to attract mates just before egg laying.
An additional school of thought supposes that the low light level in the predawn hours is a bad time for foraging for food, so perhaps it’s a good time to sing. Most bird singing in the awakening hours is done by males. That does not hold true for robins. Female robins can belt out a tune with the best of the males. It is the same for many female owls.
As the breeding season comes to a close, morning singing dies off a bit. Much time is needed for housekeeping, so there is less time for singing. Some birds prefer to warble away at dusk, rather than dawn. The sparrows are very vocal in the early evening hours.
We humans learn to talk by listening to other humans talk. It is nearly impossible for someone born deaf to know what most sounds should sound like. It is somewhat different for birds. Young birds do develop singing from birth, but they refine their songs by listening to adult birds. Birds have a special sound-producing organ called a syrinx. It is equivalent to the human voice box. Air from the bird’s lungs passes over the membranes in the syrinx. The membranes vibrate and produce the sound.
A few birds sing when flying. But they are in the minority. While most of us can walk and chew gum at the same time, birds have to alight to sing. The starling is an amazing character. Starlings will mimic sounds they have heard, including car horns, police sirens, and telephone rings. They will work pieces of those songs into their singing.
A bird joke: What do you get when you run over a robin with your lawnmower? Shredded Tweet