Night Wing (Dallas, Texas)

from the Austin Chronicle:

"Officially titled "Night Wing," the rotating, purple metal sculpture of a bat in flight by Dale Whistler at the corner of South Congress & Barton Springs Road honors Austin's most famous part-time residents. Every evening around sundown from mid-March through October, 1.5 million Mexican free-tail bats soar off into the night, in columns that look like wisps of smoke."

www.io.com/house/sculpture.html