See a swoop of swifts? Why a group of birders is trying to count them all

London, Ont., group is monitoring and protecting the bird species as population declines

At dusk in September, Winifred Wake can often be found sitting on a lawn chair in London, Ont., watching hundreds of birds circle chimneys.

She's counting chimney swifts, threatened tiny black birds that pass through southwestern Ontario during their fall migration journey to Central and South America.

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"I think they're a fascinating part of nature," she said. "This time of year, hundreds will spend nights together in old unlined brick chimneys."

Wake is a member of Nature London, a group of 50 volunteers who work to monitor and protect the birds and other species.

The chimney swift is of great interest, as their populations have declined by more than 90 per cent since 1970, according to Birds Canada, landing them on the federal Species at Risk Act list.

chimney-swifts-in-london-ont 2/Submitted by David Wake via CBC

Swifts circle a chimney in London, Ont. The threatened birds can be spotted around old unlined chimneys on their migration journey just before and after sunset. (Submitted by David Wake)

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Nature London, which is affiliated with Ontario Nature and Nature Canada, monitors 18 chimneys in the city, keeping track of swift populations from year to year.

"They're continuing to decline, and it's important we provide protection for birds," said Wake.

"They're very much dependent on the goodwill of humans to preserve some of these chimneys for them to have habitat to nest in or to rest for the night and roost.

"We don't have as many or any old growth forests with hollow trees where they could nest or roost anymore, so that habitat is gone."

winifred-wake-of-nature-london/Michelle Both/CBC

Winifred Wake stands outside a warehouse, one of 18 chimneys where she and other volunteers with Nature London count and monitor chimney swifts at dusk. (Michelle Both/CBC)

Each bird also eats about 1,000 insects a day, but with insect population in decline, habitat loss and extreme weather, their food source is dwindling.

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Hub for chimney swift advocacy

Earlier this week, volunteers counted over 300 swifts at a warehouse sporting chimneys in south London, while another 300 were counted near the downtown. The numbers change day to day as new birds arrive and others continue to migrate.

London has earned a reputation as a hub for chimney swift knowledge and advocacy.

In the past two weeks, wildlife rescues from Quebec and eastern Ontario came to the city to release orphaned chimney swifts with Nature London volunteers.

Connie Black drove to London from north of Kingston, Ont., to release seven orphaned chimney swifts into a group of roosting swifts. She runs a home-based bird rescue, Destined to Fly, focusing on species at risk.

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"You have a great group there that actually monitors all the roosts — which we need to know," Black said.

London earned official bird-friendly city status last year by Nature Canada, based on threat reduction, protecting natural habitats and community education.

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Wake and her group are part of those efforts.

"London has actually become probably the centre of swift monitoring activities for Ontario," Wake said.

Disrupted food chain

Glenn Berry, a volunteer with Nature London's chimney swift team, knows more needs to be done to protect the birds, which feed on insects.

"We have a bug-hostile world now," he said. "We've been at war with bugs for quite a while, but that's also a food source that's part of the food chain that's been disrupted."

Wake agrees.

chimney-swift-babies/Submitted by Connie Black via CBC

Some of the orphaned chimney swift babies cared for by Connie Black of Destined to Fly bird rescue, located about 30 km north of Kingston, Ont. (Submitted by Connie Black)

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"Insect populations have been plummeting, and that is considered a major reason why they're in decline," she said. "People need to be aware that we have responsibilities for caring for the rest of the creatures in the world."

Planting more native species of plants, protecting natural areas and reducing roadside mowing would help, she said.

"Anything people can do to reduce your ecological footprint to help the planet and help swifts is all good."

The story, written by Michelle Both, was originally published for CBC News.