NEST and ROOST HABITATS by the CHIMNEY SWIFT (CHAETURA PELAGICA) in MANITOBA Timothy F

OCCUPANCY OF UNCONVENTIONAL NEST AND ROOST HABITATS BY THE CHIMNEY SWIFT (CHAETURA PELAGICA) IN MANITOBA Timothy F. Poole Manitoba Chimney Swift Initiative c/o Nature Manitoba 401-63 Albert Street Winnipeg, MB R3B 1G4 [email protected] Gordon Ogilvie c/o Nature Manitoba 401-63 Albert Street Winnipeg, MB R3B 1G4 The Chimney Swift (Chaetura pelagica, Figure 1) nests in chimneys throughout deciduous- dominated habitats east of the Rocky Mountains.1 Manitoba and Saskatchewan are at the northwest periphery of the global breeding range of this species.2 In Manitoba, swifts breed from the southeast of 3 the province as far north as The Pas. This species has adapted to FIGURE 1. Chimney Swift. Photo credit: Christian Artuso. urbanisation by nesting in chimneys, although the Chimney Swift is still temperature when compared to other long-distant aerial insectivores, known to nest in large, hollowed chimneys, most notably in May and bringing forward the suggestion that out, dead trees in deciduous forest.1 early June when swifts are selecting population declines are linked to the Nesting chimneys in Manitoba are nest sites.4 use of pesticides.1,9 Long-term nest usually at least 40 cm across inside Breeding Bird Survey estimates monitoring in St. Adolphe, south of although some are as small as suggest that the Chimney Swift Winnipeg, suggests that hatching 30 cm across.4 In the southern parts population has declined by 95 per and fledging rates in Manitoba are of their breeding range, Chimney cent between 1970 and 2005 in low, and that severe summer storms Swifts have successfully nested in Canada.6 The reasons for such a increases the rate of nest failure.10 artificial towers.5 However, despite decline are varied and complicated. Since 2007, the Manitoba considerable efforts to replicate these In Manitoba, 14.5 per cent of Chimney Swift Initiative (MCSI) has artificial towers in Manitoba, there 200 known chimney sites were conducted regular monitoring of has been no recorded use of the either capped, lined or demolished roost and nest sites in communities original design, let alone successful between 2007 and 20167, although across Manitoba. The assumptions breeding attempt observed.4 studies suggest that loss of habitat is used to identify Chimney Swift The reasons for such failure likely not significant in other jurisdictions.8 habitat have been formalised reflect the inability of these towers Chimney Swift rates of decline are in documents prepared by the to maintain a relatively stable similar to those experienced by Manitoba Chimney Swift Initiative 10 BLUE JAY SPRING 2020 VOLUME 78.1 FIGURE 2. 1960s used to identify Critical Habitat under the Manitoba Endangered Species and Ecosystems Act, and to inform stewardship activities by MCSI.7 The following observations are taken from reports by volunteers from MCSI. Results Use of ‘Screened’ Chimneys It is commonplace for many building owners to restrict access to the interior of a chimney by installing a screen over the top. It is our supposition that most building managers target the exclusion of mammalian and larger avian species, especially Raccoons (Procyon lotor), and the Rock Pigeon (Columba livia). One type of screen takes on the form of a five-sided cage, which is attached to the top of the chimney, thus preventing access by larger animals, including the Chimney Swift. On June 8, 2018, a volunteer was FIGURE 2. Damaged pest exclusion screen accessed by Chimney Swifts in Winnipeg. Note the spark arrestor is covering a lined flue and the exclusion cage is over an open flue. Photo credit: Timothy Poole. monitoring a known conventional brick roost chimney on Portage from observations and analysis Methods Avenue, Winnipeg. It became of data produced by around 100 MCSI volunteers participate in apparent during the evening that annual volunteers.4 In identifying the National Roost Monitoring there were two distinct groups of habitat for Chimney Swifts, MCSI has Program (NRMP) which takes place swifts feeding in this area, one on operated under the following general on four evenings each spring. While the north side of Portage Avenue assumptions: programs in other provinces focus near the known roost, and one on • Chimney Swifts only occupy on roosts in spring, MCSI focuses the south side where there were no unlined brick chimneys with more on nest sites through the full known Chimney Swift nest or roost internal dimensions of 30 cm season and volunteers are constantly sites. The volunteer investigated square or more; on the lookout for new sites. MCSI in the hopes of finding a new site • Chimney Swifts avoid chimneys volunteers are encouraged to search on the south side. At 21:00 h, an with any type of liner; for new potential chimneys. Indeed, adult swift was observed removing • obstacles on the chimney regular monitoring has built a cadre a twig from a Manitoba maple (Acer entrance are a hindrance to use of observers who look everywhere negundo) and appeared to drop into by swifts; and discover odd things. a previously unrecorded chimney on • almost all communities containing Monitors watch the chimney for a the south side of Portage Avenue Chimney Swifts are known to set period, recording the times when (twig gathering is a sign of nest MCSI and its partners, but not all swifts enter or leave the chimney building11). On closer inspection, chimneys are known. site. Nesting chimneys are defined the chimney appeared to have two However, since 2016, the MCSI has against roosting chimney via the level flues, one being lined with metal documented numerous cases in which of daytime use. Volunteer monitors and capped using a spark arrestor, these assumptions do not hold. submit observations on monitoring and the other having a pest screen forms. This information has been (Figure 2). At 21:36 h, two Chimney SPRING 2020 VOLUME 78.1 BLUE JAY 11 Swifts entered the chimney through the Wolseley neighbourhood of chimney. Observations made during the screen. By doing so they revealed Winnipeg was lined with a metal the day on July 27 confirmed that that there was a hole in the screen sleeve during upgrades to the a breeding attempt was underway due to corrosion and age. Another boiler system. MCSI observations inside the chimney. The chimney was swift attempting to enter through had recorded breeding attempts in also occupied by swifts in 2019. this screen at 21:40 h appeared this chimney from 2013 to 2017. to make contact, deflected off the Manitoba Sustainable Development Double-flues screen, made a second pass, and discussed this loss of habitat for Of the chimneys on churches entered the chimney. Chimney Swifts with the building and presbyteries in Quebec, over 50 While still watching the same owners and it was agreed removal of per cent were closed to swifts by group of birds, the volunteer noticed a pest exclusion screen from another the installation of a spark arrestor two Chimney Swifts entering a chimney on the building would be or hat which prevents access to the chimney on a taller apartment appropriate mitigation. This screen chimney.6 Observers may assume that building nearby at 21:55 h. This was removed in May before Chimney the presence of sheet metal on top of chimney had two flues, one open, Swifts returned to Manitoba. Follow- a chimney is indicative of capping but and one with a pest exclusion screen. up monitoring on June 4 recorded a in some cases, a chimney may have a The swifts were observed entering pair of Chimney Swifts entering the second open flue. through a hole in the pest exclusion In July 2015, a Chimney Swift was screen, and not into the apparently observed using the second chimney open chimney. at St. Ann’s Roman Catholic Church Both these chimneys were on Hampton Street, Winnipeg, even monitored later in the summer. At though there appeared to be a spark the first site where nest building arrestor and hat preventing access. behaviour had been noted, behaviour On closer inspection, it was apparent indicating the parents were tending that the top only covered one half young on August 5, 2018 confirmed of the chimney, leaving a separate this as a nesting site. The other flue open for swifts to access (Figure screened chimney hosted 10 roosting 3). There is also no suggestion that Chimney Swifts on August 8, 2018. the presence of a tall object on In addition, four other chimneys with the chimney was deterring swifts broken pest exclusion screens were from accessing the open flue. This occupied by Chimney Swifts in 2018, same pattern has been observed in all in Winnipeg, although detailed several other chimneys in Winnipeg, data are not available. Melita, and Portage la Prairie, and in London, Ontario.1 Removing the Cap from a Chimney A large chimney on St. Avila School in Fort Richmond, Winnipeg had been used as a roost and nest site in 2009 and 2011 before it was capped with sheet metal c. 2014. The cap blew off in a windstorm in 2016 and a breeding attempt was made by swifts in 2016. Unfortunately, observations by MCSI volunteers suggested that the breeding attempt failed in August FIGURE 3. Two chimneys at St. Ann’s Church, 2016. Winnipeg. The chimney in the foreground has two In late April 2018, a chimney flues. In the foreground is an open flue, and the spark arrestor covers a closed flue. The chimney on the Fleetwood Apartments in to the right is two bricks wide only. Photo credit: FIGURE 4. Inside of clay-lined chimney at Trinity Timothy Poole. United Church. Photo credit: Gordon Ogilvie. 12 BLUE JAY SPRING 2020 VOLUME 78.1 Clay-lined Chimneys in another clay-lined chimney at Chimney Pots Clay-lined chimneys provide a Olina’s Jewels on Saskatchewan On June 21 2016, a Chimney poor substrate for Chimney Swifts to Avenue, Portage la Prairie.

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