This Neighborhood Jukebox Plays for Free — The Northern Mockingbird

“Hush little baby, don’t say a word.  Pappa’s gonna buy you a mockingbird.  If that mockingbird won’t sing, Papa’s gonna buy you a diamond ring.”  Northern Mockingbirds pretty much do nothing but sing.  So you can kiss that diamond ring goodbye.  A loud and indefatigable songster and consummate mimic, a Northern Mockingbird structures his song phrases so that each one repeats between two and six times, followed by a savoring pause and then a different phrase.  Lather, rinse, repeat all day—and some nights too by an unmated male. (Note that California Thrashers are also mimics and repeat phrases in their songs.  However, a thrasher’s song has more squawks, rattles, and screeches than the more lyrical mockingbird song does.  Also, a thrasher generally changes its phrases after only one or two repeats while a mocker often goes on for longer.)

Although both sexes may sing, a male’s repertoire often contains more than 150 distinct song types.  It sounds as though the bird is trying out everyone else’s song, looking for one he likes.  Besides bird songs, this accomplished mimic integrates other noises of human-inhabited areas including car horns, doorbells, and cellphone ringtones.  These birds don’t rest on their laurels, though.  Spring and fall song repertoires overlap by only 1%, so the birds are continually trying out new songs. Also, only one- to two-thirds of the songs in one spring’s repertoire occur again the subsequent spring; the rest are new.  Even the mocker’s scientific name (Mimus polyglottos) highlights its vocal abilities—“many-tongued mimic.” Its common name refers to its habit of copying (“mocking”) the calls of the birds in its neighborhood.  “Northern” simply refers to the range of this mockingbird—more northerly than its cousin, the Tropical Mockingbird.

Long, lithe, gray grenadiers of gardens and yards, both sexes are leaden gray above; two narrow, scalloped white wing-bars; pale or somewhat buffy below with a whitish throat; and a pencil-fine dark line connecting the bill and the eye.  The Northern Mockingbird has a short, thick, black, slightly curved bill and its long, narrow, animated tail—emphasized by a blackish center and conspicuous white side—droops when the bird is perched or is held cocked up slightly when it forages on the ground.  In flight and during a “wing-flashing display,” a mocker’s wings sprout large white patches looking like cotton balls (visible above and below).

Widespread in San Diego County, mockingbirds occur commonly in agricultural and urbanized areas throughout the coastal lowland and lower foothills. Familiar residents for many of us, they prefer bushes, hedges, thickets, and thorny vegetation.  Throw in a bit of open habitat, such as a well-trimmed lawn, and a chimney or satellite dish to perch on, and it’s perfect for mockers to move in.  They like to sit high and conspicuously, aggressively defending their territories from other birds, dogs, cats, and humans.  (Protect your head during breeding season!)

Adults glean prey both on the ground and in foliage. They dine on a wide variety of arthropods (e.g., beetles, ants, bees, wasps, grasshoppers), spiders, snails, lizards, and small snakes. A visual hunter, a mocker typically runs a short distance, stops, and lunges at prey on the ground. Occasionally it hawks insects from the air, as flycatchers do.   Adults also consume berries from elderberry, mistletoe, blackberry, toyon as well as prickly pear cactus fruit.

Mockingbirds build their nests in trees or shrubs with dense screening foliage or protective thorns. The male sings to defend a territory and attract a mate, often leaping a few feet in the air and flapping his wings while singing. The male builds most of the nest’s foundation and the female adds the lining and incubates the eggs. Clutch size ranges from 2 to 6 eggs; incubation lasts 12−13 days. Both parents feed the nestlings and the young leave the nest roughly 12 days after hatching; however, they don’t fly well for about another week. Mockingbirds typically raise two to three broods per season, with the male feeding the fledglings up to three weeks post-fledging while the female initiates a new clutch.

At once both a prince and a hooligan, the Northern Mockingbird seldom ventures far from the spotlight of human attention.  No other grayish bird adds so much color to our lives, although not always welcomed.  Ear-dependent birders—those who rely heavily on bird calls and songs to spot and identify a species—can never truly relax if a Northern Mockingbird is in the area.  Was that really a Cassin’s Kingbird?  Did I just hear a Western Bluebird?  I’m sure that’s an American Kestrel’s call.  Anybody see it?  A bit off in the distance, a sly grin creeps over a Northern Mockingbird’s face as he ponders his next selection.