We estimated population trends for 3 time periods: the entire survey interval (1966 - most recent data), an early period (1966 - 1979), and a recent period (1980 - current year). For all periods, we provide the estimated population trend (in %/year), a measure of its statistical significance (either a P value, or stars: *: P < 0.10, **: P < 0.05, ***: P < 0.01), and the number of routes on which trends were estimated. For the entire survey interval results, we also present the 95 % confidence interval of the trend estimate, and the weighted regional abundance of the species (average birds/route).
These results are presented for regions with at least 14 samples. Regions include States and Provinces, physiographic strata (indexed by number, e.g. S05 is the Mississippi Alluvial Valley), BBS regions (Eastern, Central, and Western), Fish and Wildlife Service Administrative Regions (Regions 1-6, RE1-RE6), The United States, Canada, and the Entire survey region (1CO). Details: Trend Estimation