Nature’s Silver Lining : Following the quake and a ‘winter of discontent,’ spring brought solace to a Northridge yard through the sweet sounds of a mockingbird.

This was “the winter of our discontent” in Los Angeles, and I for one have felt some depression after the earthquake, even though I personally suffered little loss. I believe it is partly from the initial shock, partly from aftershock “reminders,” and partly from seeing that the city around me is going to be a long time recovering.

Therefore, it was reassuring this spring to find that nature is also capable of offering up one of its cheeriest satisfactions right in my own yard.

Every spring since we moved into our house in Northridge 22 years ago, a mockingbird has sung all night in a bottlebrush tree. It is doing so again this year.

The stream of musical utterance is unending and unrepetitive. There are no other sounds in the air save distant traffic. Such is the splendor of this singing that the first year I heard it I recorded it to send back to my mother in Minnesota where mockingbirds, alas, do not bless the day or evening air with their voices.

My bird handbook shows that mockingbirds make permanent residence across the entire southern United States. There are related species south of us in the Americas, but none elsewhere. These irrepressible musicians create an exclusively New World symphony.

It is an uncanny display, and I have concentrated for 20 minutes and more at a time without hearing a single musical phrase reprised. The other night I thought, “Oh, there’s another bird answering,” because the pitch level of the notes went way down, but then I realized no, it’s just a part of my bird’s repertoire.

I know the mockingbird mimics other birds and other sounds, but its “computer storage” must be enormous, for none of those sounds is immediately present to its hearing or has been heard in our cul-de-sac for hours. I have tried my own whistle with its own rhythmic beat and found the mockingbird picking it up for a phrase or two.

According to some additional reading I’ve done, mockingbirds ( Mimus polyglottos , the “many-tongued mimic”) have been known to imitate as many as 150 different species, including the storied nightingale brought over in cages from England--sound spectrographic recordings showed the mockingbirds sang exact reproductions of every liquid, lyric nightingale note, even to pitches beyond human hearing.

And other birds aren’t the only things they mock, one throwing a high school football game into confusion by imitating the referee’s whistle, another joining in an outdoor Washington symphony concert to mimic the flute imitating the bird calls in “Peter and the Wolf”!

Why does this bird sing at night? Maybe to have the whole sound stage to itself. No other bird competes. But I can imagine other birds up, as I am, their beaks open, like my mouth, in head-shaking awe at this scintillating, exuberant, never-stop performance.

I asked Kimball Garrett, ornithologist at the Los Angeles County Museum of Natural History, about this, and he says the nighttime singing of an expanded repertoire may reflect the quality of my bird’s territory. It is the male that sings, and such virtuosity could proclaim his prowess in possessing a good perch in a good tree in a good open area which he commands. The operatic auditioning of multiple “roles” probably serves also to attract and hold a mate as well as to intimidate rivals.

And why does the bird continue for weeks and months through spring and early summer? Garrett suggests elevated hormonal levels that call forth song even beyond territorial and mating functions. Until the hormone fades, he simply must sing.

I know from Garrett that in 22 years, at least three or four generations of mockingbirds have inhabited the tree with the melodious outpouring. But that is not the way it seems to me. It seems like one bird, the same bird, through all the years, on the same branch in the same dark hours; as unchanging and entrancing as earthquakes seem to be unpredictable and wrenching.

I would like to think it is the same bird, returned each year to cheer my spirits, astonish my ear, dumbfound the whole neighborhood. So that even if earthquakes come, mysterious, sudden and potent, we know that there are other natural events, more regular, more frequent, more welcome, if no less mysterious, to help heal our shaken souls.

The Mockingbird: A Master Mimic

Sonograms show the amazing ability of mockingbirds to imitate other species’ bird songs. This mockingbird was recorded in 1975. The vertical axis shows the pitch of the sounds, the horizontal axis the elapsed time. The mockingbird matched each note closely but delivered them at a faster rate. “The mockingbird was in a very excited state and delivered about 12 different mimics all in very rapid succession,” a researcher reported.

(graphic)

Source: Borror Laboratory of Bioacoustics, Department of Zoology, Ohio State University.