Chimney Swifts – Monitoring & Conservation Initiatives

The Chimney Swift is a small, sooty-grey bird that once nested and roosted inside hollow trees in old-growth forests. For shelter it now relies mainly on old, unlined brick chimneys. Swifts come to land only to enter their chimneys, where they cling vertically, held by strong claws and braced by stiff, spine-tipped tails. Swifts construct nests from tiny twigs held together and to the inner wall of the chimney by their glue-like saliva.

Swifts are aerial foragers, which means they capture insects on the wing. They generally hunt high above roof tops and the urban tree canopy. In London, swifts are mainly found downtown, and in older industrial and residential areas. They winter in the upper Amazon basin, returning to London in late April and departing by early October.

In 2003, members of Nature London learned that Chimney Swifts were in serious decline. To try to learn more, that fall they began counting migrating swifts as they dived by the hundreds into a few big old chimneys to roost for the night. By the next fall they had identified more roost chimneys and organized a regular monitoring schedule.

Chimney Swift numbers in Canada have declined by more than 90% since 1970. Causes are complex but include problems with the food supply, declining availability of suitable sites for nesting and roosting, and the challenges of an increasing number of extreme weather events.

In 2009 the Chimney Swift was officially designated as Threatened under both federal and provincial species-at-risk legislation. Its federal status was reconfirmed in 2018. Numbers continue to decline.

Over the years, members of Nature London have been carrying out a number of initiatives aimed at learning more about swifts and helping in their conservation.

Undertakings fall into two general categories (which are often intertwined):

Monitoring: Documenting the use of London chimneys by Chimney Swifts is the premiere endeavour of the London swift program. At present, monitoring activities consist mainly of

  1. Counting migrating and other non-breeding swifts as large numbers enter chimneys to roost communally for the night (May to Oct, once a week, at about a dozen chimneys).
  2. Searching for additional chimneys used by swifts for roosting.
  3. Identifying chimneys used by nesting swifts (just one pair per chimney).
  4. Documenting the use of chimneys by swift families and determining nesting success.
  5. Organizing training sessions and mentoring volunteer monitors.
  6. Compiling data from the London monitoring program and preparing reports.
  7. Tracking rates of loss of local chimneys used by swifts.

In 2010 Birds Canada launched a provincial initiative, Ontario SwiftWatch. The Nature London program operates independently but shares all its monitoring data with the OSW database. Since 2003, more than 180 chimneys used by swifts have been identified in London, though about one-third have since been lost to capping or demolition. Undoubtedly, more swift chimneys remain to be found. During the 2021 swift season, local volunteers carried out 375 monitoring visits at 52 London chimneys.

The London swift monitoring program ensures that as many chimneys as possible are monitored; that all data are submitted in a timely fashion; and that volunteers are trained, receive regular updates of count results and are generally kept happy. Volunteers usually sign up before the start of swift season (May to September), but new monitors are welcome at any time. Learn more about Nature London’s swift monitoring program here: Intro to Swift Monitoring.

Conservation (including Education and Outreach): Working towards the conservation of Chimney Swifts and their habitat is a major focus of the London swift program. Typical activities include

  1. Delivering PowerPoint presentations about swifts to schools and community groups.
  2. Responding to inquiries; writing articles about swifts.
  3. Preparing educational materials for diverse audiences (e.g., website, displays, handouts).
  4. Reaching out to owners of swift chimneys to encourage them to be good swift hosts.
  5. Advocating for the protection of swift chimneys (landowners, governments, NGOs, etc.).
  6. Promoting native plantings and the protection of natural areas to provide habitat for the insects that swifts rely on for food.
  7. Making input on swift-related issues to policy documents, governmental processes, etc.
  8. Collaborating with others to advance swift conservation.
  9. Teaming up with swift rehabilitators to facilitate releases of hand-reared orphan swifts.

Nature London’s Chimney Swift volunteers are a very informal group. If you would like to learn more or get involved in helping with Chimney Swift monitoring, education and conservation, we welcome you. Please contact us at To learn more about Chimney Swifts and Nature London’s associated activities, please see our Chimney Swift Resources.

Winifred Wake, Chimney Swift Liaison
Sandy Symmes, Coordinator of Monitoring

March 12, 2019