CHICAGO (CBS) — This is the season for a hardy band of volunteers who wander the dark streets of the Loop, trying to save migrating birds who’ve smacked into buildings.

WBBM Newsradio’s Mike Krauser walked in the Loop before sunrise Wednesday with Annette Prince of the Chicago Bird Collision Monitors.

“We pick up as many as 300 birds in a single day,” Prince said.

LISTEN: WBBM Newsradio’s Mike Krauser reports

Prince runs the volunteer group, which scours the Loop for migrating birds.

“They’re birds that hit the windows,” she said. “They’re stunned; they have different degrees of injuries.”

Most of the birds will recover, if bigger birds such as seagulls and crows don’t get them first.

“A lot of warblers, hummingbirds, tiny birds that are flying all the way to South America,” Prince said.

A tip came in while Krauser walked with Prince, from Mike Leonard, who sells newspapers at Daley Plaza.

“I always (phone in tips), and they come. Sometimes the seagulls eat them,” he said.

A magnolia warbler was found nearby. That bird did not survive, but a few seconds later, another bird was found still alive and only stunned.

Chicago Bird Collision Monitors save about 3,000 birds a year. The rest go to the Field Museum.

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