The most reliable source of information for the Barn Swallow is the Breeding Bird Survey (BBS). Although the species' breeding range extends north of the area covered by the BBS, Barn Swallows only occur sporadically in this area, often in association with human habitation and roads (Lepage 2007). The BBS reveals a long-term and continuing decrease across the entire breeding range in Canada and, to a lesser extent, in most of the United States. Although the annual indices from the current BBS analysis do not show strong changes in the temporal pattern of decline (see Canada graph below), other analyses, using the same data set, suggest that the decline has been greatest since the 1980s (e.g., Nebel et al. 2010, Smith et al. 2015). The magnitude of that decline has decreased over the most recent period (2006-2016). Varying levels of decline are seen among the Bird Conservation Regions (BCRs) and appear particularly severe in the Boreal Hardwood Transition and the Atlantic Northern Forest BCRs, but also in the west (Northern Pacific Rainforest and Great Basin BCRs). Results for all BCRs with reasonably reliable data are displayed below. The long-term population goal is based on the BBS; the Barn Swallow population is below the lowest acceptable level relative to that goal (see Canada graph below). Once the Recovery Strategy is developed under the Species at Risk Act, this goal will be re-examined.
Additional information on: Breeding Bird Survey (BBS) - Canadian analysis
