Peggy Notebaert Nature Museum serves as official way station for migrating monarch butterflies

CHICAGO (CBS) — The Peggy Notebaert Nature Museum is celebrating monarch butterflies as they pass through in their annual migration south.

The event is fittingly called “Flutter into Fall.”

This time of year is the peak time to see monarch butterflies in Chicago – but the window is short. The butterflies are mid-way into their migration to Mexico.

Monarchs have recently been classified as an endangered species, and the museum is part of a worldwide effort to help them survive.

The butterflies are caught, and tiny tags are put on them to track their trip – and learn more about them.

“It seems really remarkable that they can travel more than 2,000 miles – that a single individual butterfly that weighs about as much as a paperclip can make such a long journey,” said Dr. Doug Taron, chief curator of the Peggy Notebaert Nature Museum, “and of course, tagging has provided very good evidence that that’s the case, because you stick the tag on here in Illinois, and it’s still on the butterfly when it gets to Mexico when somebody finds it.”

Monarch Watch has certified Notebaert as an official monarch way station because the museum’s grounds include food and other resources the butterflies need to keep their migration going.