Common nighthawk (Chordeiles minor) COSEWIC assessment and status report: chapter 7
Habitat
The breeding habitat of the Common Nighthawk includes open habitats, such as sand dunes, beaches, recently logged areas, recently burned-over areas, forest clearings, short-grass prairies, pastures, open forests, peatbogs, marshes, lakeshores, gravel roads, river banks, rocky outcrops, rock barrens, railways, mine tailings, quarries, urban parks, military bases, airports, mines and commercial blueberry fields (Peck and James, 1983; Gauthier and Aubry, 1996; Poulin et al. 1996; Manitoba Avian Research Committee, 2003). The species is also present in mixed and coniferous forests, as well as in pine stands (Gauthier and Aubry, 1996). In Alberta and Saskatchewan, canyons, grassy plains and dune complexes are also favoured habitats for the Common Nighthawk (Dale et al. 1999; A.R. Smith, pers. comm. 2005). At the beginning of the 20th century, the species also nested in cultivated fields, corn and potato fields, orchards, parks and gardens in residential areas and railways (Gross, 1940). Since the end of the 1870s, it has also used flat gravel-covered roofs in urban areas for nesting (Gross, 1940). Although nighthawks may have benefited from the new habitats provided by urban areas, they generally prefer natural sites (Brigham, 1989). It is not clear, however, what proportion of the Canadian population breeds in poorly surveyed areas, such as the boreal forest.
Little is known about the habitat trends of the Common Nighthawk in Canada (Poulin et al. 1996). In the early days of European settlement, the Common Nighthawk probably took advantage of newly opened habitat created by extensive deforestation in the eastern United States and parts of Canada (Poulin et al. 1996). The appearance of gravel rooftops on urban buildings in the second half of the 19th century further contributed to the expansion of Common Nighthawk habitat in North America (Weir, 1989; Gauthier and Aubry, 1996) to the point that, at the beginning of the 1990s, the species bred almost exclusively on the roofs of buildings in urban areas in Ohio and Pennsylvania (Peterjohn and Rice, 1991; Brauning, 1992).
Since the beginning of the 20th century, however, forest fire suppression and changes in forest harvesting practices that reduce the number of open areas, along with extensive reforestation and intensive use of agricultural land, have all contributed to the decline in the quantity and quality of Common Nighthawk habitat (Gauthier and Cyr, 1996; R.M. Brigham pers. comm. 2007). Similarly, gravel rooftops are gradually being replaced by tar-covered roofs, which further reduce the amount of available breeding habitat in urban areas (Poulin et al. 1996). Habitat does not appear to be declining in some areas. For instance, in the Maritimes logged-over areas, commercial blueberry fields, coal mines and gravel quarries, which provide suitable breeding habitat, are constantly being created (S. Blaney, pers. comm. 2005).
In Canada, the quantity of habitat available to the Common Nighthawk or the degree of habitat protection on public lands is unknown. Some habitat on public lands will undoubtedly be protected by the creation of protected areas, although these areas account for less than 8% of the total area of Canada (Natural Resources Canada, 2005). There are no programs for the protection of Common Nighthawk habitat within Canada’s protected areas. Nevertheless, controlled burning programs in specific national parks could increase the species’ habitat (Campbell et al. 1990; R.M. Brigham, pers. comm. 2005). In managed forests, there are no specific programs for Common Nighthawk habitat protection.
Data are equally lacking on the level of habitat protection for this species in private areas (i.e. urban and agricultural areas).
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