Dedicated to Chandler S. Robbins, originator of the survey.
2015 RESULTS: Most Recent Update: 7 February 2017.
This website presents population change information for more than 400 species of North American birds, as estimated from the North American Breeding Bird Survey. Estimates of trend (interval-specific estimates of population change), annual indices of abundance, and maps of abundance and population change for these species are presented for a variety of regions.
This website contains the 1966 - 2015 BBS analysis results. These results have undergone internal review. See our disclaimer for cautions regarding the analysis and its interpretation.
Results presented on this website are based on outputs from a series of statistical analyses of BBS data. To conform to USGS data release protocols, we have reviewed the results, and prepared metadata. The full datasets of trend and annual indices analyses are provided in csv format, and can be downloaded from these links:
1. This is the first public version of the 2015 analysis.
We welcome comments on the results presented here. Public review and feedback regarding the results are a critical part of the scientific review of the website, and we thank you in advance for taking a careful look at these summaries.
2. Some parts of the website (e.g., the community dynamics section) have not been updated. Alaska results have not yet been computed for 2015.
3. BBS taxonomic classifications are updated periodically, and the Analysis and Summary Website is presently consistent with the 52nd supplement to the AOU Checklist . Recent taxonomic changes, (e.g., Clapper/Ridgway Rails) have not been incorporated into the BBS analysis. Sage and Bells Sparrows are grouped for analysis. Note that the order of presentation of species lists might not follow taxonomic order, and some of the grouped taxa may appear at the ends of the species list for a region.
4. A minor change was implemented in the counting of sample sizes. In past analyses, we calculated the number of routes on which the species was observed at least once. However, some of these routes were not included in that analysis due to limited data on the route or because it occurred in a stratum that did not meet the minimum sample size requirements (4 routes) for that stratum to be included in the analysis. Excluding these routes lead to slightly smaller sample sizes that better reflect the actual number of routes contributing informatiton to the analyses. The analysis has not changed; we only modified how we computed number of routes included in the analysis.