Chances are you've seen -- and heard-- dozens of them in any Austin parking lot. They're grackles, iridescent-winged black birds with a distinctive call, and they may be getting a little too close to some students at the University of Texas.

The school's environmental health and safety division put up flyers in the area near Gregory Gym this week.

The flyers warn of aggressive birds and suggest people do what they can to stay out of their way.

Central Texas grackles are known to be noisy, brave and maybe even angry.

"Around this time of year, they generally have nests so that's when they can get aggressive," said Caitlin Friesen. She is a graduate student studying ecology, evolution and behavior.

"It's hard when they are a species that's so closely linked to humans use patterns to avoid them completely," added Friesen.

That's why UT posted flyers earlier this week warning people spending time at the new picnic tables near Gregory Gym that the birds can be aggressive.

Freisen thinks an increase in construction and a decrease in open space may be to blame.

"They could have the sort of vantage points of the trees that allow them to look out for predators, whereas on campus now you have not so many wide open spaces," she added.

The sign doesn't trouble Ph.D. student Chris Burnett.

"I mean, I'm not worried about my well-being or safety around them that's for sure. But there are a lot of them," he said.

He points out the grackles aren't the only populous species near Gregory.

"The squirrels can be just as much of a nuisance as the birds for sure," he said

KVUE's cameras caught that firsthand, although Monique Arriaga didn't seem to mind sharing her crackers.

"It's actually more entertaining for me. Birds don't usually get that close to me anyway," she said.

As KVUE's Tina Shively showed her the grackle flyer, she seemed to wonder if her snacks could be the problem.

"Should I, like, stop feeding the birds?" she asked.

There are no flyers for that, just yet, anyway.