The most reliable source of information for the Northern Rough-winged Swallow is the Breeding Bird Survey (BBS), which provides good coverage of the breeding population concentrated across southern Canada. BBS results indicate a large, long-term decrease in abundance since 1970 throughout the species' Canadian range, including in the west where population abundance is highest. The continental population has remained relatively unchanged over the same time period. Results for all Bird Conservation Regions (BCRs) that host the species in Canada and for which there are reasonably reliable results are shown below. Like most other swallow species in Canada, the Northern Rough-winged Swallow is below the lowest acceptable level relative to its national population goal (see Canada graph below). In this case, the species dropped below acceptable levels in the late 1980s.
Additional information on: Breeding Bird Survey (BBS) - Canadian analysis