Widely distributed in Canada, the Tree Swallow is a familiar swallow of open fields, meadows, marshes, and other wetlands. The Breeding Bird Survey indicates a moderate decrease in its Canadian population since about 1970. Causes for this decrease are unclear. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.
The Tree Swallow is one of several species of aerial-foraging insectivores showing widespread declines in Canada. Causes of these declines remain unclear, but changes in aerial insect abundances have been suggested as one possible common factor, as well as changes in the ladnscape, insecticides, and climate change (Blancher et al. 2009, Nebel et al. 2010). However, a recent study in the Maritime Provinces suggests that the breeding success of Tree Swallows was not linked to insect abundance (Imlay et al. 2017). The Tree Swallow is a cavity-nester that uses natural holes in trees where available, but also readily accepts nest boxes. It may be negatively affected by reduced nest-site availability and/or competition with House Sparrows and European Starlings (Winkler et al. 2011).
Environment and Climate Change Canada and partners have developed Bird Conservation Region Strategies in each of Canada’s Bird Conservation Regions (BCRs). In these strategies, selected species are identified as priorities for one or more of the following reasons:
Select any of the sub-regions below to view the BCR strategy for additional details.