The most reliable survey for Vaux's Swift in Canada is the Breeding Bird Survey (BBS), which indicates a moderate decrease in population size since early 1970s. However, the precision of the Canadian trend estimate is considered medium and relies in part on data from the species' range-wide trend. The BBS also covers less than half the breeding population in Canada. This assessment is therefore considered to have medium reliability. BBS results from throughout North America also show a moderate decrease. The Vaux's Swift is below the lowest acceptable level relative to its national population goal (see BBS Canada graph below).
Additional information on: Breeding Bird Survey (BBS) - Canadian analysis
