I’d like to correct a few misconceptions in the article on “Why do grackles congregate?” published in The Leader of Jan. 6, 2018. First of all, the large flocks of birds that are the focus of Mr. Kuhlmann’s article are made up of more than just grackles! Next time you see a flock of birds gathering on utility wires in the evening, take a closer look: they are not all the same size. In addition to common and great tailed grackles, these huge congregations include many starlings and brown-headed cowbirds (both species are a little smaller than grackles).
It’s hard to tell them apart during the evening when they are lined up in silhouette, but during the day the species can easily be distinguished, not just by their size, but by their plumage. Male grackles are much larger with longer tails than the females, and during breeding season are a spectacular glossy blue-black. The smaller females are brownish. Brown-headed cowbirds are also sexually dimorphic: males are glossy black with brown heads; females are a dull brown. Adult starlings of both sexes are iridescent purplish black with lighter speckles.
All these birds are year-round residents in Houston; they do not migrate. Grackles and cowbirds are native to North America, and are related to blackbirds and orioles (the Icteridae family). Starlings, sometimes called “rice birds,” are an introduced species that originated in Europe, and are related to myna birds (Sturnidae family).
Furthermore, none of these birds are true scavengers. Grackles in particular are omnivores that eat many insects (you can see them foraging for insects in grassy areas during the day), but they will also eat minnows, frogs, eggs, berries, seeds, grains, and even small birds and mice. And yes, they will eat remnants of human food when it’s available. Starlings are also omnivores, while cowbirds eat mostly insects and seeds.
These large mixed-species congregations are a winter phenomenon; in spring and summer the birds disperse for the breeding season. The birds’ main choices for congregation sites appear to be places that have lots of overhead wires, where they gather en masse in the evenings, before moving to settle down for the night in trees with lots of sheltering foliage. The Kroger parking lot on 43rd Street offers both of these amenities. Food trash in the parking lot also provides easy pickings during the winter when insects and other more natural food items are scarce.
I was glad to read the conclusion of the article suggesting that these birds are worthy of our admiration, not our scorn or disgust, and that we should just accept them (but perhaps avoid parking under the trees where they roost at night). There is no sure-fire method to drive them away, and furthermore the native species, grackles and cowbirds, are protected by the Federal Migratory Bird Act (it is illegal to kill them). Keep in mind that this is a seasonal problem. Once spring comes and the birds start thinking about finding a mate and raising a family, they will go their separate ways until the next fall.