Peak Purple Martin time has begun
Each year as school gets underway on campus, tens of thousands of the birds congregate nightly in the trees just to the north of the emergency room.
The birds will be here for a few weeks before they head to South America for the winter.
While the Purple Martins are here, bird watchers will throw blankets in grassy areas along 44th Street near Clarkson Tower or stand in the Don and Millie's parking lot to view the birds as they hover over campus around dusk to feed on insects.
The video above was filmed one night last year just before dusk.