Why Do Grackles Flock To Grocery Store Parking Lots at Dusk?

Some birds are well-liked. Some are considered pests. Many just slip under the radar – but not the grackle.

By Mose Buchele April 1, 2016 9:30 am| ,

This story originally appeared on KUT News.

The grackle demands that you take notice. Pamela Gooby certainly did.

“It’s like this big velvet wave of grackle in the parking lot of the grocery store,” she says.

She’ll sometimes see those velvet waves of grackles in the parking lot of her regular H-E-B.

So, her question, in case you haven’t already guessed it, was this:

Why do grackles seem to flock to H-E-B parking lots at dusk?

With that, it’s time for a lesson in grackles or, as Fort Collins-based ornithologist Walter Wehtje sometimes calls them, Quiscalus mexicanus.

Wehtje did his dissertation on the geographic expansion of the three subspecies of great-tailed grackles. He first encountered the birds visiting Texas, and ended up spending years tracking grackle populations in Mexico and the western United States.He says that, in order to answer Pamela’s question, it helps to understand the history of grackles and humans living together. It goes back a long, long way.

“It actually predates the Spanish conquest of Mexico,” he says.

In the 1400s, there was an Aztec Emperor named Ahuitzotl – a relative of Montezuma. His armies conquered the lowlands to the east of Mexico City, what was then the empire’s capital, Tenochtitlan.

“On their return, not only did they bring back slaves, but they brought back these large black birds that they were enamored by because they produce these long black iridescent feathers,” says Wehtje.

The Aztecs loved using feathers for their clothes and for decorations.

“They brought back these grackles and bred them in [what’s now] Mexico City, and after a while, started releasing them, and said that they were not to be harmed.”  This may be the first recorded case of humans intentionally relocating wild animals in the New World. It also means that 500 years ago there were already great-tailed grackles flocking to cities. Some of the grackles we see in Texas today could be related to those Aztec birds from hundreds of years ago.

And, Wehtje says, if you go down to present-day Mexico, you’ll see the exact same pattern. If you go into a Mexican town, usually they have a central square with some shade trees in it. And in the evening, the great-tailed grackles fly into those shade trees to settle down for the night.

Sound familiar?

Consider any supermarket parking lot, like the one at H-E-B. If you’re a grackle looking to bed down, this place has everything you want. You have plenty of space. And if you’re a grackle, you love to sleep in large groups.

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