How do birds get inside Denver International Airport?

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DIA Birds
Michelle P. Fulcher/CPR News
Small birds like sparrows are often seen inside Denver International Airport’s terminal and concourses.

It isn’t just human passengers who fly in and out of Denver International Airport, as Jill Mullen noticed when she got off a late flight a few weeks ago.

The airport was deserted – quiet enough for her to hear birds chirping overhead. Then she spotted one “sort of hanging out on the banister of those walkways that move really quickly.”

Mullen saw something that’s actually not all that unusual inside DIA – sparrows and other small birds that fly over the crowds or drop down to scavenge crumbs from the floor. In fact, she’d seen them a time or two before. But this time, she was curious enough to reach out to our Colorado Wonders page to learn more.

“I love birds and I was just a little concerned about what happens to them,” said Mullen, a health policy advisor at the Colorado Division of Insurance.

Airport spokeswoman Ashley Forest said birds get into DIA the same way humans do. “We have a lot of doors through all of the terminals and the jet bridges, so it’s easy for them to come in … We have birds in the area because our airport is actually near the Central Migratory Flyway. So it’s pretty easy for them to get in – and out – of the airport.”

Hart Van Denburg/CPR News
While DIA has a staff of professional biologists who monitor wildlife outside the airport, no one tracks the species of birds inside the terminals.

The flyway is a giant air route for migrating birds in the spring and fall. Millions of other birds call the prairie around DIA their full-time home. When the birds are outside, they eat what’s available there. When they stray into the airport they often snack on food people leave behind. 

DIA has a full-time team of professional biologists to monitor wildlife but they spend most of their time outside, worried about bigger animals that could damage planes. No one tracks the number, or the species, of the small birds that fly around inside the airport’s terminal, Forest said. The best thing for human travelers to do is avoid feeding the birds or leaving food scraps behind. 

“Let nature be,” she said. “You know, we have lots of doors opening so nature sometimes comes through those doors – and they will leave through those doors as well.”

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