Chimneys suit these cigar-shaped birds; modern venting does not.
The twittering of chimney swifts has been a familiar sound in the skies over our towns and cities for more than 150 years.
Looking for all the world like little flying cigars, these insectivorous birds adapted readily to the urban development of eastern North America during the Industrial Revolution of the mid- to late-1800s.
When the clearing of land removed millions of trees from the North American landscape — and, therefore, millions of nest sites for birds — the creation of brick chimneys provided a timely substitute for this fast-flying species known taxonomically as chaetura pelagica.
Wall-clingers, rather than branch- or wire-perchers, these birds were ideally suited to the vertical aspects of chimney dwelling. With a wide variety of flying insects adapting to city life at the same time, swifts were able to find food sources right outside their new homes.
The freshly dubbed "chimney" swifts flourished in the urban landscape, becoming a familiar part of town and city life.
Fittingly soot-coloured, they fly rapidly on thin, pointed wings that bend back in a crescent shape. Their bodies are only about five inches long but their wing span is about a foot from tip to tip. They winter in the Amazon rainforest and typically arrive here in late April or early May. By the middle of August many of them have already begun their "fall" migration. By the end of September it is rare to see a chimney swift in Ontario.
More often heard than seen, these ariel foragers fly almost continually in the daylight sky, chasing down flies, beetles, termites and flying ants high overhead.
Learning to listen for their high pitched calls is one of Phyllis Tremblay’s favourite spring and summer activities. She, like many other nature enthusiasts, has joined a volunteer program called SwiftWatch that monitors chimney swifts to see where they roost and nest.
"A summer evening in downtown Barrie is enhanced by the vibrant chittering of chimney swifts as they circle overhead," she observes with enthusiasm. "Hearing that sound as they slice through the air in graceful arcs alerts me to their presence."
The reason Phyllis and other SwiftWatch volunteers are out there looking and listening for chimney swifts is because the little insectivores have now become a species at risk.
COSEWIC, the Committee On the Status of Endangered Wildlife In Canada, has noted a dramatic decline in Ontario's chimney swift population. A comparison between data collected in the first Ontario Breeding Bird Atlas survey (1980-1985) and the most recent survey (2000-2005) shows that the province’s population of chimney swifts has decreased by almost 50% over the past two decades.
One of the factors involved is the disappearance of available nesting and roosting sites. Many modern homes and buildings now have capped chimneys that prevent swifts from entering. In some cases, alternate heating and venting systems have done away with chimneys altogether.
SwiftWatch volunteers do a number of things during their urban excursions. They make chimney inventories, habitat assessments, population counts, and presence and absence surveys.
This latter activity involves documenting the comings and goings of chimney swifts in areas of suitable habitat. When there is an absence of swifts from viable nesting or roosting sites, the zero count poses some interesting questions about why swifts are not there. Food availability, climatic factors, and the timing of chimney cleaning are all possible contributors to this situation.
Bird Studies Canada has received important data about chimney swifts from over 200 volunteers since Ontario's SwiftWatch program began in 2009.
As Phyllis notes, "After five years of monitoring, my heart still skips a beat when I see a chimney swift circle a chimney, then enter it to roost for the night. Discovering a new roost or nest site is as thrilling as finding a new bird for my life list."
SwiftWatch, like the Ontario Bird Breeding Atlas survey, is an excellent example of "citizen science" at work. Programs like these recognize — and welcome — the contributions of amateur naturalists who have an avid interest in nature and want to help preserve habitat and wildlife in the modern world.
With the guidance of Bird Studies Canada, SwiftWatch volunteers follow a prescribed protocol that provides guidelines and standardized methods for data-taking and observation.
Clubs such as the Brereton Naturalists of Barrie have promoted public awareness of chimney swifts through events such as "Swift Night Out," an evening walk held in June. At a similar outing in Toronto around the same time, Rob and Angie Mueller said that "upon arrival we could only see two or three birds but, as the sun was setting, hundreds more arrived. We wondered where the heck they all came from!"
Angie recalls a similar experience in Nova Scotia a few years ago. More than 100 swifts circled above a large chimney at dusk, all moving in the same direction for a while, then, one by one, they started descending into the opening to roost for the night, "like a column of smoke going back into the chimney."
"Swift things are beautiful," Elizabeth Coatsworth observed in a famous poem of the same name. Hopefully, efforts such as SwiftWatch can help to make such things endure.