The North American Breeding Bird Survey

Dedicated to Chandler S. Robbins , originator of the survey.

2024 RESULTS: Most Recent Update: May-2024.

This website presents population change information for 548 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. Analysis results have undergone internal USGS review (IPDS IP-120797, Approval 10-13-2020).

Users can obtain BBS analysis results from 3 sources:

1. The Map-based Results Server
2. Summary Results Pages ("Survey results" menu)
3. Spreadsheets (csv format) containing results

Primary Results and Metadata are available as csv files through USGS-Sciencebase:

• Hostetler, J.A., Sauer, J.R., Hines, J.E., Ziolkowski, Jr., D.J., Lutmerding, M., and Skalos, S.M., 2025, The North American Breeding Bird Survey, Analysis Results 1966 - 2024: U.S. Geological Survey data release, https://doi.org/10.5066/P13NU2PR.

Metadata for 1966-2024 Analysis:

• BBS Analysis Results Metadata (File:BBSAnalysis_Results_Metadata_1966-2024_final.xml)

Notes:

1. This is the first public version of the 2024 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. The summary and display components, revised for 2024, are DRAFT and are subject to revision.
2. Starting in 2017, BBS results have been presented for a "Core" survey area (strata in which at least some routes have data extending from 1968 to present), and for an "Expanded" survey area that contains the Core strata as well as several non-Core strata in Alaska and northern Canada that were not consistently surveyed prior to 1993. Of the 548 species for which we estimate trends, 426 of them occur in the Core Region (Core Species), and for those species we present trends both for core strata and for Expanded area strata. For Core Species, results for both 1966-2024 and 1993-2024 are presented for Core portions of US, Canada, and Survey-wide for these species. Regions that are labeled as "Expanded" are based on all strata (Core and non-Core) and results for those regions are only computed for 1993-2024. The remaining 122 species (i.e., Non-core Species) only (or primarily) occur in the Expanded survey area, and for these species we only present results for expanded regions over the interval 1993-2024.
3. Due to changes in USGS webserver protocols, we have been required to dramatically revise our presentation of results, and some products presented in earlier versions of the website could not be updated. We are working to provide additional results and to restore archived results from prior years.
4. BBS taxonomic classifications are updated periodically, and the Analysis and Summary Website is presently consistent with the taxonomy provided by the BBS data, as described in Pardieck, K.L., D.J. Ziolkowski Jr., M. Lutmerding and M.-A.R. Hudson. 2018. North American Breeding Bird Survey Dataset 1966 - 2024, version 2024.0. U.S. Geological Survey, Patuxent Wildlife Research Center. https://doi.org/10.5066/F76972V8.

General Information

Data Liability Disclaimer

• Although these data have been processed successfully on a computer system at the United States Geological Survey (USGS), no warranty expressed or implied is made regarding the accuracy or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. It is strongly recommended that these data are directly acquired from a USGS server, and not indirectly through other sources which may have changed the data in some way. It is also strongly recommended that careful attention be paid to the contents of the metadata file associated with these data. The USGS shall not be held liable for improper or incorrect use of the data described and/or contained herein.

  So, these data are provided "as is" and without any express or implied warranties, including, without limitation, the implied warranties of merchantability and fitness for a particular purpose. Also, use of trade names or commercial products in this home page is solely for the purpose of providing specific information, and does not imply recommendation or endorsement by the U.S. Government.

Introduction

• What is the Home Page?
  • The BBS Summary and Analysis Website is a source of information about population change and distribution of 548 North American bird species. This version of the website has a greatly changed format from earlier versions, adopting map-based approach to species summaries. This website is a companion product to the BBS Operations Website. The BBS Operations Website is the appropriate source for "raw" (unsummarized) BBS data, for additional information on the details of running and maintaining the survey, and for links to additional BBS resources.

• What is the BBS?
  • The BBS is a large-scale survey of North American birds. It is a roadside survey, primarily covering the continental United States, Alaska, and Canada, although survey routes only cover regions that have roads. The BBS was started in 1966 and now contains over 5,000 survey routes which are surveyed in April-July by experienced birders.

    The primary objective of the BBS has been the estimation of population change for bird encountered along roadsides. However, the data have many potential uses, and investigators have used the data to address a variety of research and management objectives.

• How does the Results and Analysis Home Page work?
  • The website provides information on population change estimates of bird species at several geographic scales;

    The 2024 version of the website provides summary results for all species in spreadsheets and also provides results through a scalable map. We provide results that have been reviewed, as consistent with USGS regulations regarding release of information. On-the-fly interactive programs permit additional analyses that are based upon the same underlying analyeses but permit more flexibility in regions and time periods of summary.

• Supplemental Information
  • Analysis and interpretation of BBS data is tricky, because the survey incorporates information from a huge geographic area and the survey varies greatly in quality of information over the area. To document some of the problems with the analyses of BBS data, and help you interpret the results presented on the Home Page, we provide a series of help files that provide information on the survey, discuss problems with its analysis, and tell you how the presented information should be interpreted. We suggest you read the help files for each category of information before looking at the results.

    Help files and metadata are presented with summary data, and are also available in the References and Additional Information link on the web site.

• Comments and Disclaimers
  • We welcome comments on the home page. We intend to improve it as new methods for summary of survey data are developed, and in response to user feedback. We caution that, as always in data analyses, the possibility exists for errors in the analyses and summaries.

• Acknowledgments
  • Any analysis of BBS data must first acknowledge the large number of observers who conduct the counts. These counts are a lot of effort, and require a great deal of skill. We greatly appreciate their efforts. Of course, Chan Robbins, the originator of the survey, was a the primary source of energy and inspiration for analyses and interpretation of this challenging data set. A variety of data managers and coordinators, including Chan Robbins, Ted Van Velzen, Danny Bystrak, Sam Droege, Bruce Peterjohn, Keith Pardieck, and David Ziolkowski (on the US side), and Tony Erskine, Marie-Anne Hudson, Connie Downes, and Bev McBride (on the Canadian side) have contributed to the program. We especially thank the many editors and data managers and other BBS staff who have contributed to the analysis for making the data and their expertise available to us.

• Contacts and Roles and Responsibilities
  • Analysis of BBS data: John R. Sauer and William A. Link conducted the statistical analysis of trends and annual indices presented in this website. John R. Sauer prepared the summary datasets and wrote the metadata for the analysis.
  • Summary website: James E. Hines developed and implemented the summary website. John R. Sauer and James E. Hines collaborated in the design and preparation of content for the website.
  • BBS Operations and Data Management: David J. Ziolkowski, Jr., Mikey Lutmerding, and Keith L. Pardieck manage the operation of the BBS and its data management, and prepared and distribute BBS data.

References and additional information

• Link, W. A., and J. R. Sauer. 2002. A hierarchical model of population change with application to Cerulean Warblers. Ecology 83:2832-2840.
• Sauer, J. R., J. E. Fallon, and R. Johnson. 2003. Use of North American Breeding Bird Survey data to estimate population change for bird conservation regions. J. Wildlife Management 67:372-389.
• Sauer, J. R., and W. A. Link. 2011. Analysis Of The North American Breeding Bird Survey Using Hierarchical Models. The Auk 128:87-98.

General Information About the BBS

• About BBS (from Operations Website)
• Overview of BBS
• North American Fauna - BBS Monograph This links to a comprehensive summary and analysis of the BBS data covering the period 1966-2011.

Papers Describing Technical Aspects of BBS Analysis

(pdf reader required)

• Description of Current Model Set and Models for BBS Analyses (Link, Sauer, and Niven 2020, Ecology)
• Description of Hierarchical Model for Estimation of Population Change (Link and Sauer 2002, Ecology)
• Paper Describing Expanded BBS Region (Sauer et al. 2017, Journal of Fish and Wildlife Management)
• Comparative Analysis of Hierarchical Model and Route Regression Trend Analyses (Sauer and Link 2011, The Auk)
• Bird Conservation Regions and BBS Analysis (Sauer, Fallon, and Johnson 2003 Journal of Wildlife Management)

Taxonomic Information

• A Note on Taxonomy
• Why are Some Species Grouped?