The Mystery of Grackles flocks in supermarkets

Dr. Jessica Yorzinski, assistant professor in the Department of Ecology and Conservation Biology and Schubot Center member has helped solve the mystery of why groceries stores parking lots get crawling with huge flocks of grackles each January here in central Texas.  In an interview with KXAN News, an NBC affiliated television station, Dr Yorzinski explained why these birds display such a particularly interesting behavior.

“Grackles behave differently in winter months. They don’t hang around in small groups of two or three individuals like in the spring and summer. In the winter, they like to roost in big groups; sometimes groups of hundreds or thousands of birds” Dr. Yorzinski said. She also explains that during the winter, these blackbirds really prefer to stay around grocery stores parking lots, and along the side of major roads because they are attracted to the lights at night, and that allows them to remain active even in the darkest hours of the night.

In the interview, she also explains the uniqueness of grackles as birds. She and her team of researchers from Texas A&M have discovered that these birds are capable of moving each eye independently and that grackles are the only birds known to have this ability. Grackles also like to “murmurate”, Dr. Yorzinski explains, which is a fascinating behavior where hundreds, if not thousands, of birds, fly and change direction together. This behavior is uncommon in birds in the United States.

Common Grackle (Quiscalus quiscula). Picture: Simon Kiacz

Take a look at the whole interview and learn a bit more about this sometimes annoying but fascinating bird. To learn more about Dr. Yorzinski’s work please visit

Take a look at other publications about Grackles in parking lots written by Schubot Center director Dr. Sarah Hammer and her team.