The largest of the North American swallows, the Purple Martin is a familiar bird across most of eastern and central Canada, with an outlying population in coastal British Columbia. The Breeding Bird Survey indicates that, at a national level, the population has decreased by about 42% since 1970. The greatest magnitude of decrease is found in the Lower Great Lakes / St. Lawrence Plain Bird Conservation Region, where the species reaches its highest density. Since the early 1900s, the Purple Martin has been almost entirely dependent on human-made bird boxes for nesting sites (Brown and Tarof 2013). This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.
The population of many swallows, swifts, and nightjars have decreased across much of North America and show a negative change point in the trend in the 1980s (Smith et al. 2015). The large decrease in the population of Purple Martin in the Great Lakes area suggests that the species may be affected by some of the same factors causing declines in other aerial-foraging insectivores (e.g., changes in aerial insect populations, as well as landscape changes, toxic chemicals, and climate change; Blancher et al. 2009, Nebel et al. 2010). In the eastern part of its North American range, this cavity-nesting species currently breeds almost entirely in human-made structures and bird houses (Brown and Tarof 2013). Purple Martins may be negatively affected in some areas by reduced nest-site availability and competition with House Sparrows and European Starlings, as well as pesticide use on the wintering grounds (Brown and Tarof 2013). By 1985, the Purple Martin was nearly extirpated in British Columbia but the population recovered after the provision of nest boxes on the marine foreshore (Cousens and Davidson 2015). The species is particularly sensitive to cold weather, which affects their ability to find insect prey; adverse weather kills more Purple Martins than all other sources of mortality (Brown and Tarof 2013).
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.
