The mockingbird didn’t return to our place this spring, to my great disappointment. It was like going to a concert expecting to be wowed by an artist, only to find the lead singer in the band didn’t show up.
Mockingbirds are in the Mimidae or mimic family, along with the catbird and thrasher. They are all good impersonators, but the mockingbird stands in a class by himself.
There is a distinct motif to each of their songs. The catbird mimics individual notes. The thrasher strings out his song in two-note phrases. The mockingbird repeats each note three to seven times and mixes them up in a unique mockingbird manner.
The given name of the mockingbird is mimus polyglottis, “the many-tongued mimic.” This virtuoso can imitate up to 200 bird songs, as well as a variety of other sounds such as a barking dog, a squeaky wheel, a car alarm and the whistle of a mailman.
All these different sounds are created by a remarkable organ called the syrinx, which is found in songbirds. It is similar to our larynx but so much more refined.
The syrinx is divided into two parts and each one is capable of producing sounds independently of the other. Birds can create a blend of two different notes and vary them independently, which is something we can’t do with our one-track larynx.
All great singing begins by imitation, and imitating sounds is not an easy thing to do, as anyone learning the musical scale for the first time is quick to discover.
First you have to hear the sound accurately, and then you have to translate it into a motor command in the larynx. The translation almost never comes out right the first time. So, you practice, over and over, and gradually the sound of your voice comes closer to matching the notes you hear.
Mockingbirds are very good at this. Like us, they learn to sing by trial and error, practicing until they can copy the song of a cardinal and nuthatch and robin with almost perfect fidelity.
The mockingbird’s ability to mimic songs is pretty remarkable, but he does something with it that is even more remarkable. He strings the songs together into something that sounds more like a musical composition than a haphazard medley of imitations.
There is a rhythm and beat to the song, which can go on for half an hour or more. The phrases come in groups of three to seven, the harsh call of a jay mixed in with the sweet warble of a finch. In contrast to the mimicked notes, the song is never sung the same way twice.
No bird sings with such voluminous gusto, with such verve and tireless energy. You can usually find him on the top branch of the tallest tree, pouring out a steady stream of song. He sings not just with his voice but with his whole body, leaping into the air and hovering momentarily, as if to attract more attention to his singing.
The mockingbird’s song makes little sense. There is no clear reason for mimicry in the avian world. No one is fooled, not even one of the 200 birds that are mimicked. And there is certainly no clear reason to imitate the sound of a car alarm.
The only apparent function of the mocker’s song is to attract a mate. Studies indicate that the singing is not territorial, since it is directed to a female rather than to the male competitors entering the territory.
But why is the song so elaborate, so musical, so long and drawn out? And why is it sung in a different way every time?
The answer, or a good part of it, seems to lie in that wonder of evolution called sexual selection. The song is not the creation of male genius but of female choice. In other words, he sings because she likes it.
The mockingbird’s song probably began with a few simple notes, and then a female saw something in it that struck her fancy. Something like music perhaps. The trait was greatly exaggerated over many generations until it grew into the wonder it is today. A wonder full of useless beauty.
Apparently, there is no explaining a lady’s fancy, be it in man or bird.
I heard a mockingbird singing his heart out in the dark one night, when no one could hear him. There he was, practicing like an artist in rehearsal, honing his skill for the dawn premier before a female audience.
It was enchanting, listening to that sound in the darkness, and I wondered if the mockingbird found some pleasure in it too. Maybe it was just another piece in the puzzle of extravagance. Maybe he was just singing for the joy of song itself.
Richard Weber is a nature enthusiast living in Ellis County.