What's Flying Into The Old Winery Chimney?

They look like bats, thousands of them, swarming into the chimney at the Winery/Powerhouse building in Farmington every night around dusk.

But according to Dawn Vezina of the Organization for Bat Conservation at Cranbrook Institute of Science in Bloomfield Hills, bats aren't likely to appear in numbers quite that large. Vezina believes the chimney is occupied at night by Chimney Swifts, a breed of bird that is migrating this time of year.

"In this area, a colony of hundreds of bats would be rare," Vezina said, adding that Chimney Swifts in the fall start to flock in large numbers. "At the end of the summer, they begin their migration back to Peru." 

Chimney Swifts also make a unique chirping sound, she said. 

According to allaboutbirds.org, a website created by the Cornell Lab of Ornithology, the birds are similar to bats in that they eat small, flying insects. They don't perch, but instead use their long claws "to cling to the walls of chimneys and other vertical surfaces," according to the website. 

The population of Chimney Swifts appears to be dwindling, because today's covered, narrow flues have cut down on nesting sites. 

If you'd like to watch the birds over the next few weeks, stop by the Winery/Powerhouse building, on Grand River west of Orchard Lake Road, around 7:45 p.m.