Photos by cottonmanifesto
Urban species #128: Gray catbird Dumetella carolinensis
The halfway point between Vernal Equinox and Summer Solstice passed a week ago, so soon we should cease our obsessive tally of Signs of Spring. But not yet. My partner, Alexis (cottonmanifesto), has been most anxious for one particular sign, and I am happy to report the first catbird of Spring 2006, Boston. I can also report the second through fiftieth, as once this bird arrives in the city, they become among the most common avian residents. Their habit of perching fairly low (around eye-level) and the fact that they tolerate close approaches by humans makes them one of the most observable migratory birds. That is, if you choose to notice it. Being fully dark and mostly gray, and preferring thick shrubs rather than trees to perch in, catbirds may be completely passed by, by busy city people.
My first encounter with a catbird was in a postage stamp sized backyard in the Boston borough of Brighton. On the other side of a rusty chain link fence was a scrubby vacant lot, overgrown with ailanthus, knotweed, and bittersweet. I heard a curious "meow," that was strangely uncatlike. To my surprise, a gray bird with shining black eyes was perched right at the edge of the tangled wire and vines, within an arm's length; We regarded one another for short peaceful moment, before it moved on to its business. From then on I looked forward to visits from this bold yet sneaky neighbor.
The catbird can be seen eating fruit from ornamental shrubs, or turning over leaf litter for insects. At other times it can be heard singing its heart out, in a riot of snippets from other bird's songs. The catbird is in the mockingbird family, but unlike the northern mockingbird, which sings its sampled melodies in repetitions of three, the catbird rapidly blurts unrepeated phrases. The effect is similar to a scat singer, or a jazz soloist. Walking along the muddy river, one can pass by half a dozen of these performances, feathered buskers who never ask for change.
Northern Mockingbird Mimus polyglottos
Well known and well loved, the mockingbird is a fairly common urban bird in many areas. Before the middle of the twentieth century, however, it was very rare in New England. One of the things we see time and time again is that urban species are "preadapted" to living alongside humans: they have some habitat requirement that just happens to coincide with the way that humans alter the landscape. The widespread planting of multiflora rose (the clusters of berries in the above photo are multiflora rose hips), seems to be responsible for much of the expansion of the mockingbird's range. The tangles of thorny growth make for good nest sites, and the persistent fruits provide winter food.
Another factor favoring mockingbirds as urban animal is their behavior; in short, they are bold--not deterred by human activities and pets, often attacking cats and other animals that come too close to a nest. Both males and females sing, using snippets "sampled" from other birdsong, in phrase-groups of three. Unpaired males will even sing at night--once I left a party in the wee hours to hear a loud emphatic mockingbird in the needles at the top of a suburban spruce tree. I stood listening for a few minutes, amazed and incredulous; I actually thought that it may have been a recording that someone had installed for some reason!
Mockingbirds are notable urban animals in another way: they will incorporate human-produced sounds in their repertoire. Car alarms and cell phone tones have made their way into the songs of contemporary mockingbirds.
( two moreCollapse )