Why Are Grackles Flocking to Texas Supermarkets?
January isn't just the season for New Year's resolutions and returning the holiday gifts that you're not crazy about. It also seems to be the time of year when Texans start to notice giant flocks of ominous-looking black birds perching in supermarket parking lots. The great-tailed grackle is native to Texas, and they have a habit of congregating near artificial light sources — like the ones that you'd find outside a shopping center.
"Folks go out grocery shopping at night at H-E-B and you see what could be hundreds of grackles roosting up in the trees," Jessica Yorzinski from the Department of Ecology and Conservation Biology at Texas A&M University, told KXAN. She added that the birds like to roost — sometimes by the hundreds, if not the thousands — near those lights, so they can "remain active" during the overnight hours.
KUT, the NPR station in Austin, has also attempted to explain the birds' presence. One question that was submitted to their ATX Explained series was "Why do grackles seem to flock to H-E-B parking lots at dusk?" Walter Wehtje, a Fort Collins, Colorado, based ornithologist, told the station that the birds aren't interested in the H-E-B itself (or the Kroger, which tends to be one of their go-to stops in Houston).
Supermarket parking lots tend to have shade trees where they can roost, and the trees give the birds cover from any would-be predators, as well as an excellent vantage point to keep watch from. And the sheer size of a supermarket parking lot means that there's enough room for all of the grackles which love to roost in huge groups. "If something happens, there are more of you to warn about it," Wehtje said. "And, then, if something attacks, the risk of getting attacked by a predator goes down."
He also added that they tend to be fans of the fast food restaurants that might share a parking lot with those supermarkets. "They love French fries."
All of that echoes the Houston Audubon's official description of the bird. "Great-tailed Grackles [...] can be found in any area inhabited by humans that has some trees," the organization writes. "They tend to congregate in large flocks and prefer shopping centers and fast-food store parking lots where there's trash for food and trees or light posts for perching."
Although thousands of grackles can be an annoyance — novelist Edward Carey wrote that their call sounds like "the loud and unwelcome shrieks of rusty machinery" — they're not the worst kind of wildlife you can encounter in a parking lot. Last spring, a shopper in Rome, Italy was surrounded by a half-dozen wild boar as she left a supermarket, and they aggressively helped themselves to her groceries.
Yeah, we'll take the birds.