What goes up must come down, and when a gull pilfers a fry from your basket, what goes up as potato comes down as bird poop.
It is a common scene at City Dock, visitors forking over chips and treats to herring gulls, causing the birds to crowd together for easy food. But the joy of inter-species snack sharing may be tempered when the gulls inevitably defecate all around the harbor, Maryland Department of Natural Resources Biologist Jonathan McKnight said.
“It’s bad for paint jobs,” he said.
Other birds like mallard ducks and Canada geese join and try to get people food, which is bad for the birds. Different birds crowded together could spread diseases to one another, such as avian cholera and botulism, McKnight said, or perhaps even illness biologists are unaware of.
“It’s rare in nature where you have a whole bunch of different kind of animals all coming together in one place,” he said. “The interaction, driven by the drive to get Fritos, is a little out of what would happen in the natural world.”
In some cases, birds fed too much sweet processed food can develop a droopy wing called angel wing, which is neither pretty nor fun, McKnight said.
Don’t feed the birds people food, no matter how much the gulls whine. He said if you want to get more enjoyment out of seeing wildlife, consider a wilder trip to a place where humans haven’t altered the birds’ habitat.
“We would encourage people to go interact with wild animals in the wild as opposed to taming wild animals in tame places like Ego Alley,” he said.
Research from the University of Exeter in England has found that gulls prefer food that has been touched by humans, indicating that the gulls are taking cues on what to eat from humans.