Amy-Lee Kouwenberg is co-ordinator with the Maritime Swiftwatch Program of Atlantic Bird Studies Canada, located in New Brunswick.
She says chimney swifts are swallow-like birds that roost in chimneys.
But, when they return to Nova Scotia from wintering in South America, they all pick the same chimney to spend the night in.
And that chimney, in Caledonia, is at the McGowan Lake Fish Hatchery.
The organization is having an event on May 20, at dusk, so people can watch the birds fly in and land in the chimney.
“On the way these little birds all roost in chimneys altogether, so that’s how we get this phenomenon all these little birds entering a chimney at the same time, and they stay in there for the night, and then later they’ll all pair off to do their own chimneys, and their own little nests.”
The McGowan Lake Fish Hatchery has been seeing the return of chimney swifts for years, she says.
Kouwenberg says they use a big chimney that used to be part of an old foundry.
“So hopefully what we’ll see is near dusk, the birds will sort of start swirling around and you’ll hear them twittering, and then they start dropping into the chimney, one by one, and sometimes a whole bunch of them at once. They sort of funnel into the chimney.”
She says last year at that roost, there were 253 birds in the McGowan Lake Chimney.
“We’re hoping for a good number of birds going in,” she says. “It’s quite a spectacle to see them all go in in such a big group.”
Later, the birds pair up, and find their own chimneys to roost in.
The birds eat insects “which is wonderful, because we don’t love insects,” she says.
Chimney swifts are a species at risk in Canada, and the organization is working to get volunteers and scientists to count the birds as they come home to roost.
She says when the birds do pair off and land in someone’s chimney, most people won’t realize they have new residents, because the birds are so tiny.
“Lots of people line their chimneys now and cap them, which can be a huge problem because the birds can’t nest. So we encourage people to watch for chimney swifts and to leave their chimney in a way so swifts can use it.”
She says a chimney swift nest is less than 10 centimeters wide.
“We ask people not to clean their chimney during May and October.”