Additional information on: North American Breeding Bird Survey (BBS): Relative Abundance and Breeding Distribution (1970-2016)
Legend: Categories of abundance (average birds/BBS route/year, 1970-2016) within geographic strata.Coloured squares represent "degree blocks" (1o latitude x 1o longitude) for which BBS data exist; these contribute data towards estimating the species' abundance within each stratum. The remainder of each stratum for which no BBS data exist is darkened/grey. Black area = strata with no BBS data for this species. Blue line = species breeding range (Birdlife International).
Map was produced by Adam C. Smith, Environment and Climate Change Canada, based on data from the North American Breeding Bird Survey.
