Jeffrey A. Hostetler John R. Sauer James E. Hines David Ziolkowski Michael Lutmerding 20250225 spreadsheet Reston, VA U.S. Geological Survey https://doi.org/10.5066/P1F2X4WH This data product consists of a database of population change and abundance estimates for North American birds, estimated from North American Breeding Bird Survey (BBS) data. Data are presented for 546 species of birds in 4 spreadsheets containing trend estimates and annual indices for 2 time periods. Estimates are derived for each species using the 1 of 4 alternative models, and a cross-validation model selection procedure was used to select the best model for each species. Metadata associated with this data product provides information specific to the associated analysis results; metadata for the BBS data are available at Ziolkowski, D.J., Lutmerding, M., English, W.B., Aponte, V.I., and Hudson, M-A.R., 2023, North American Breeding Bird Survey Dataset 1966 - 2023: U.S. Geological Survey data release, https://doi.org/10.5066/P136CRBV. These data files and associated web-based summary programs are designed to provide public access to analysis results from BBS data. See the North American Breeding Bird Survey Dataset (https://www.sciencebase.gov/catalog/item/52b1dfa8e4b0d9b325230cd9) for information on the most recent data release from the BBS. The BBS is hosted by the Eastern Ecological Science Center (EESC, https://www.usgs.gov/centers/eesc). Primary results are provided in spreadsheet form, and are described in this metadata. A supplemental website presents the results in alternative summary formats. A statement regarding the elements of the website, and a general discussion of the methods, is available at (https://www.mbr-pwrc.usgs.gov). Analysis of survey data can be controversial, and any user of the information should recognize that alternative approaches exist. These results are based on methods that have been peer reviewed and exist in the published literature; the most recent reference for the methods is found in Link et al. (Link, W. A., J. R. Sauer, and D. K. Niven. 2020. Model selection for the North American Breeding Bird Survey. Ecological Applications 30(6):e02137. 10.1002/eap.2137). Users also have access to all data collected by the survey, at (https://www.pwrc.usgs.gov/bbs/). Standard disclaimers for use of information are also provided (https://www.mbr-pwrc.usgs.gov/bbs/disclaim.html). Results are presented in 4 spreadsheets: 1. Long-term trends (1966(83) - 2023) from the BBS core area using Link and Sauer (2002) definition of trend as a ratio of endpoints of annual indices. (Spreadsheet name: BBS_Core_Trend_1966-2023.csv). The core area is the region used for BBS analyses in prior years (e.g., Sauer and Link 2011), and omits NWT, YT, NF, and portion of AK (BCRs 02 and 03), but includes the core area survey estimates (SU1), the contiguous United States (US1), and portions of Canada in the core area (CA1). Starting year varies from 1966-1983 [1966(83)], depending on region. 2. Trends for the interval 1993 - 2023 from an expanded BBS area and species list, computed using the ratio metric. Analysis for the expanded BBS area was initiated in 2015 to allow of incorporation of northern regions that contained very sparse data prior to 1993 (Sauer et al. 2017), and includes data from NWT, YT, NF, and BCRs 02 and 03 in AK. Summaries for the survey (SUR), the United States (US), and Canada (CA) contain results from this expanded area. (Spreadsheet name: BBS_Expanded_Trends_1993-2023.csv) 3. Annual indices for 1966(83) - 2023 from the core area. These are yearly indexes of abundance estimated using a hierarchical model analysis for regions corresponding to the long-term ratio trend estimates (1). (Spreadsheet: BBS_Core_Indices_1966-2023.csv) 4. Annual indices from 1993 - 2023 for the expanded area. These are yearly indexes of abundance estimated using a hierarchical model analysis for regions corresponding to the 1993 - 2023 ratio trend estimates (3).(Spreadsheet: BBS_Expanded_Indices_1993-2023.csv). Additional information regarding data and interpretation of results are available on the BBS analysis website (http://www.mbr-pwrc.usgs.gov/), with associated help files at (http://www.mbr-pwrc.usgs.gov/bbs/helpind15.html). The complete taxonomic species list is available at: https://www.sciencebase.gov/catalog/item/625f151ed34e85fa62b7f926. 1966 2023 Current final year is 2023. Complete Periodic revisions are made as needed to update results. The contiguous United States, Alaska, and Canada -169.8047 -48.1641 71.9654 22.5937 ISO 19115 Topic Category biota None Breeding Bird Survey Breeding Bird Survey Analysis Bird Trend Estimates Bird Annual Indices Bird Lists USGS Metadata Identifier USGS:67aba702d34e329fb20457b1 Geographic Names Information system (GNIS) United States of America Canada USGS Biocomplexity Thesaurus Birds Integrated Taxonomic Information System (ITIS) 2017 ONLINE_REFERENCE Washington, D.C. Integrated Taxonomic Information System (ITIS) http://itis.gov R. Terry Chesser, Kevin J. Burns, Carla Cicero, Jon L. Dunn, Andrew W. Kratter, Irby J. Lovette, Pamela C. Rasmussen, J. V. Remsen,Jr., James D. Rising, Douglas F. Stotz, and Kevin Winker. 2017 ONLINE_REFERENCE Unknown The Auk: July 2017, Vol. 134, No. 3, pp. 751-773. https://doi.org/10.1642/AUK-17-72.1 Daniel Niven USGS Pauxent Wildlife Research Center mailing and physical

12100 Beech Forest Road

Laurel MD 20708 USA 301-497-5676 dniven@usgs.gov expert advice; identification keys Skilled birders (volunteer observers) collect the data. Data are reviewed by USGS staff for accuracy, an if needed corrections are made, as necessary, in consultation with the observers. See bird count data source metadata for more information (https://doi.org/10.5066/F71R6NK8). Birds encountered along roadside survey routes in USA and Canada. Most birds are identified to species, but in some cases individuals are identified as other taxa (races or unidentified species groups) for data management purposes. Analyses are only conducted for species with sufficient data. Kingdom Animalia Subkingdom Bilateria Infrakingdom Deuterostomia Phylum Chordata Subphylum Vertebrata Infraphylum Gnathostomata Superclass Tetrapoda Class Aves Birds oiseaux Order Accipitriformes Order Anseriformes Order Apodiformes Order Apterygiformes Order Bucerotiformes Order Caprimulgiformes Order Cariamiformes Order Casuariiformes Order Charadriiformes Order Ciconiiformes Order Coliiformes Order Columbiformes Order Coraciiformes Order Cuculiformes Order Eurypygiformes Order Falconiformes Order Galliformes Order Gaviiformes Order Gruiformes Order Leptosomiformes Order Mesitornithiformes Order Musophagiformes Order Opisthocomiformes Order Otidiformes Order Passeriformes Order Pelecaniformes Order Phaethontiformes Order Phoenicopteriformes Order Piciformes Order Podicipediformes Order Procellariiformes Order Psittaciformes Order Pteroclidiformes Order Rheiformes Order Sphenisciformes Order Strigiformes Order Struthioniformes Order Suliformes Order Tinamiformes Order Trogoniformes none None. Standard professional attribution of the source of data set is suggested for products derived from these data. Jeffrey A. Hostetler USGS Eastern Ecological Science Center Research Biologist mailing and physical

12100 Beech Forest Road

Laurel MD 20708-4036 USA 301-497-5662 jhostetler@usgs.gov William A. Link, Daniel K. Niven, and Keith Pardieck. Results were produced a Desktop computers running the Windows 10 Enterprise Operating System. Analyses were conducted using: 1. R version 4.4.1 (2023-06-16) Platform: x86_64-w64-mingw32/x64 (64-bit) 2. Program RStudio: Version 2024.09.1 © 2009-2024 RStudio, Inc. Build 394 3. Program JAGS, called from program R. Plummer, M. 2003. JAGS: A Program for Analysis of Bayesian Graphical Models Using Gibbs Sampling, Proceedings of the 3rd International Workshop on Distributed Statistical Computing (DSC 2003), March 20–22, Vienna, Austria. ISSN 1609-395X. David Ziolkowski Mikey Lutmerding Willow B English Marie-Anne R. Hudson 2024 dataset Reston, VA U.S. Geological Survey https://doi.org/10.5066/P136CRBV Metadata regarding location accuracy for BBS samples is provided at http://www.mbr-pwrc.usgs.gov/bbs/geographic_information/BBS_Route_Analysis_metadata_2010.html. For mapping applications used in development of area weights for summary results, Arc/INFO software was used to create and maintain topological relationships between features. The Arc/INFO command BUILD was run to ensure the topological consistency of the data set. Maps may be provided in the web-based summaries that contain grid polygons which cover the land mass for North America except for Central America, Mexico and the Northern part of Canada. It is possible small islands are not covered by this grid. The NABBS was not conducted in 2020 due to travel restrictions related to the pandemic. Annual indexes associated with the year 2020 are interpolations between 2019 and 2021 indexes produced by the analysis program. No formal positional accuracy tests were conducted No formal positional accuracy tests were conducted Field Methods for summary analyses and descriptions of results has been documented in numerous publications. See citations listed below for details. Link, W. A. and J. R. Sauer 2002 Publication https://doi.org/10.1890/0012-9658(2002)083[2832:AHAOPC]2.0.CO;2 Sauer J. R. and W. A. Link 2011 Publication https://doi.org/10.1525/auk.2010.09220 Sauer J. R., W. A. Link, J. E. Fallon, K. L. Pardieck, and D. J. Ziolkowski, Jr. 2013 Publication https://doi.org/10.3996/nafa.79.0001 Link, W. A, and J. R. Sauer 2016 Publication https://doi.org/10.1890/15-1286.1 Sauer, J. R., D. K. Niven, K. L. Pardieck, D. J. Ziolkowski, and W. A. Link. 2017 Publication https://doi.org/10.3996/102015-JFWM-109 Link, W. A, J. R. Sauer, and D. K. Niven 2020 Publication https://doi.org/10.1002/eap.2137 Bird Studies Canada and NABCI 2014 Publication Published by Bird Studies Canada on behalf of the North American Bird Conservation Initiative. https://www.birdscanada.org/research/gislab/index.jsp?targetpg=bcr&targetpg=bcr David Ziolkowski Michael Lutmerding Willow B. English Marie-Anne R. Hudson 2024 dataset Reston, VA U.S. Geological Survey https://doi.org/10.5066/P136CRBV Digital and/or Hardcopy 19660501 20230731 publication date BBS Dataset 1966-2023 Sole or primary avian population data source. Analyses were conducted on a workstation using R and FORTRAN programs and a statistical program for Bayesian analysis of hierarchical models. All trend analyses and annual indices are based on a common analysis based on a model set of 4 models. Interactive summary programs provide regional trend estimates based on intermediate statistics from that analysis, and thus do not constitute a separate analysis. Regions with no data from the first 15 years of the survey period were also excluded from this analysis due to the limited time series relative to other regions. The data from these regions are available from the BBS website (http://www.pwrc.usgs.gov/bbs) for analysis. Abundance estimates from the trend portion of the program are estimated from the hierarchical model, and have variance components added to accommodate asymmetries in the lognormal distribution. Regions with limited and variable data may have large and imprecise estimates. Note that this analysis is fit using MCMC (Markov chain Monte Carlo) methods; convergence may sometimes be an issue in regions with small sample sizes or poorly conditioned data. In summaries, data deemed suspect are flagged using credibility measures. Data were taken from Ziolkowski et al. (2024), and processed into input files for each species using program R. The data set produced by Ziolkowski et al. (2024) has to be filtered to remove data not that do not meet protocol standards (see Ziolkowski et al. [2024] for details associated with route acceptability). In this dataset, we selected data for inclusion in the analysis by matching the route-year identifiers for acceptable data and prepared species-specific data sets that included zero data not included in the database and index observer information within routes. We did not include data from routes on which species were never encountered for analysis of those species. Analyses use data coded by Ziolkowski et al. (2024) as run type 1. Data included in the analysis, and procedures used to process the data have changed over time to accommodate differences in the database and changes in criteria used to judge suitability of data for analysis. Periodic revision occurs in the database and analysis results to correct errors; we note that minor differences are to be expected in datasets due to these corrections and due to changes in data standards and quality coding over time. Note that the survey was not conducted in 2020 due to pandemic restrictions. Annual indexes listed for 2020 are interpolations of adjacent data produced by the hierarchical model. The analysis is conducted within strata formed by the intersections of states/provinces and Bird Conservation Regions (BCR). Here is a listing of the strata, with associated areas. Codes for states, provinces, and BCRs are presented below. Composite trends for states, provinces, BCRs, and other regions are estimated as weighted averages of these strata. Note that a correction was made to the areas of BCRs 22 and 23 in state 66 (Ohio) for the 2023 analysis. (State or Province,BCR,Area [km^2]), (69,5,84970), (11,5,211038), (14,5,47422), (89,5,54605), (11,6,109676), (4,6,459346), (45,6,91421), (79,6,181284), (4,8,4892), (45,8,235577), (68,8,438587), (76,8,473255), (79,8,180093), (33,9,114065), (89,9,102054), (11,9,61595), (69,9,118591), (85,9,88502), (14,9,40060), (55,9,254421), (92,9,182), (17,10,9550), (11,10,395758), (85,10,2785), (33,10,106752), (4,10,55633), (92,10,168740), (53,10,162272), (69,10,54961), (89,10,23429), (81,11,89159), (79,11,244308), (50,11,70055), (53,11,85092), (45,11,70198), (54,11,15837), (64,11,128715), (4,11,151128), (36,11,31175), (50,12,88766), (49,12,87542), (91,12,46510), (68,12,206529), (45,12,15364), (76,12,173719), (76,13,27810), (72,13,8310), (87,13,4764), (68,13,83958), (66,13,21898), (61,13,53346), (87,14,20492), (56,14,73082), (18,14,1055), (65,14,58116), (61,14,29291), (76,14,71276), (75,14,6102), (47,14,5628), (44,14,82136), (58,14,19869), (14,15,53437), (55,15,1402), (60,16,135319), (17,16,149799), (6,16,95205), (92,16,11757), (33,16,915), (55,16,199), (85,16,132639), (53,17,140971), (64,17,55522), (54,17,5651), (92,17,64578), (81,17,104585), (83,18,107624), (38,18,38119), (60,18,67400), (92,18,12060), (54,18,36038), (17,18,113916), (81,18,2375), (67,18,11183), (83,19,89614), (38,19,111793), (81,19,732), (67,19,76375), (54,19,121439), (83,20,59498), (38,21,237), (83,21,153482), (67,21,42105), (54,22,21888), (35,22,44738), (67,22,15874), (52,22,83340), (81,22,3606), (91,22,1511), (36,22,108617), (34,22,123753), (38,22,66015), (49,22,4067), (50,22,10333), (66,22,39588), (34,23,3398), (66,23,12769), (91,23,97610), (36,23,7285), (50,23,49736), (35,23,13230), (49,23,58676), (67,24,7662), (82,24,40545), (66,24,1826), (2,24,8123), (39,24,69733), (52,24,86855), (38,24,105), (34,24,18580), (7,24,33651), (35,24,35919), (67,25,29784), (42,25,47483), (7,25,66056), (83,25,71232), (51,26,20377), (39,26,816), (82,26,2285), (42,26,41168), (7,26,39135), (34,26,456), (52,26,10700), (42,27,7405), (25,27,51646), (82,27,25146), (2,27,83157), (39,27,4051), (63,27,60446), (88,27,17774), (80,27,51128), (27,27,93959), (51,27,103618), (46,28,4590), (2,28,37615), (18,28,885), (39,28,30189), (72,28,97265), (61,28,37388), (88,28,39806), (47,28,716), (66,28,30877), (82,28,41449), (80,28,1767), (27,28,16202), (90,28,62910), (63,28,21189), (59,28,3825), (27,29,42656), (80,29,27253), (46,29,7126), (21,29,212), (88,29,42631), (59,29,3711), (0,29,32), (72,29,11867), (2,29,5463), (63,29,46166), (58,30,4192), (59,30,12176), (47,30,14868), (87,30,78), (61,30,5285), (21,30,4871), (0,30,138), (77,30,2615), (88,30,3555), (18,30,10982), (72,30,413), (46,30,14329), (44,30,2132), (25,31,94976), (14,32,173084), (85,33,607), (14,33,106686), (6,33,108838), (55,33,40081), (6,34,98755), (60,34,28942), (60,35,89028), (6,35,956), (83,35,102630), (83,36,70392), (42,37,25340), (51,37,119), (83,37,41294) BBS Dataset 1966-2023 2024 BBS_Core_Trends_1966-2023.csv Long-term trends (1966[83] - 2023) from the BBS core area using Link and Sauer (2002) definition of trend as a ratio of endpoints of annual indices. The core area is the region used for BBS analyses in prior years (e.g., Sauer and Link 2011), and omits NWT, YT, NF, and portion of AK (BCRs 02 and 03), but includes the core area survey estimates (SU1), the contiguous United States (US1), and portions of Canada in the core area (CA1). Starting year varies from 1966-1983 [1966(83)], depending on region. Producer Defined Sample Size Code To facilitate review of species credibility, we include a separate indicator for the sample size component of the Credibility Measure Producer defined R The sample is based on less than 5 routes for the long term (very small samples), Producer defined Y The sample is based on less than 14 routes for the long term, or Producer defined blank The sample is based on at least 14 routes for the long term Producer defined Precision Code To facilitate review of species credibility, we include sub indicator for the precision component of the Credibility Measure Producer defined R The results are so imprecise that a 5%/year change (as indicated by the half-width of the credible intervals) would not be detected over the long-term (very imprecise) Producer defined Y The results are so imprecise that a 3%/year change (as indicated by the half-width of the credible intervals) would not be detected over the long-term (quite imprecise) Producer defined Blank The results are of sufficient precision that a 3%/year change (as indicated by the half-width of the credible intervals) would be detected over the long-term. Producer defined Abundance Code To facilitate review of species credibility, we include sub indicator for relative abundance component of the Credibility Measure Producer defined R The regional abundance is less than 0.1 birds/route (very low abundance) Producer defined Y The regional abundance is less than 1.0 birds/route (low abundance Producer defined Blank The regional abundance is at least 1.0 birds/route Producer defined Credibility Code Although the BBS provides a huge amount of information about regional population change for many species, there are a variety of possible problems with estimates of population change from BBS data. Small sample sizes, low relative abundances on survey routes, imprecise trends, and missing data all can compromise BBS results. In the complicated model fitting procedures presently used for the BBS, it is possible that convergence failures in regions with these deficiencies can produce results that are inaccurate as well as imprecise. Often, users do not take these problems into account when viewing BBS results, and use the results inappropriately. To provide some guidance to interpretation of BBS data, we have implemented a series of checks for some attributes that we view as cause for caution in interpretation of BBS results. Producer defined R (Red Indicator). This category reflects data with an important deficiency. In particular: 1. The regional abundance is less than 0.1 birds/route (very low abundance), 2. The sample is based on less than 5 routes for the long term (very small samples), or 3. The results are so imprecise that a 5%/year change (as indicated by the half-width of the credible intervals) would not be detected over the long-term (very imprecise). Users should be aware that a variety of circumstances may lead to imprecise results. For example, imprecise results are sometimes a consequence of a failure of the models to converge in those local areas, even though the model performs adequately in larger regions. Producer defined Y (Yellow Indicator). This category reflects data with a deficiency. In particular: 1. The regional abundance is less than 1.0 birds/route (low abundance), 2. The sample is based on less than 14 routes for the long term (small sample size), or 3. The results are so imprecise that a 3%/year change (as indicated by the half-width of the credible intervals) would not be detected over the long-term (quite imprecise) Producer defined Blank (blank Indicator): This category reflects data with at least 14 samples in the long term, of moderate precision, and of moderate abundance on routes. Producer defined Significance An indicator variable that takes on value "1" if zero falls outside the 95% credible interval for the estimate and the trend estimate is > 0; "2" if zero falls outside the 95% credible interval for the estimate and the trend estimate is < 0; and " " (no value) if zero falls within the 95% credible interval. If the credible interval does not contain 0, the result could be judged significant. Producer defined 1 The 95% CI does not include 0 and the trend estimate is > 0. Producer defined blank 0 is inside the bounds of the 95% CI Producer defined 2 The 95% CI does not include 0 and the trend estimate is < 0. Producer defined Region Region Codes consist of 3-character summary codes for State ID and state/province names, 3-character ID codes for Bird Conservation Regions (BCRs), and additional 3 character codes and names of larger regions such as countries and administrative regions for the Breeding Bird Survey. In the result spreadsheets for trends, the full names of the BCRs, state/provinces, and other regions are listed as well as a region code. The core BBS area (for which trends are computed from 1966-2022) does not include information from MWT, YT, NF, and BCRS 02 and 03 in AK, and the core areas survey-wide estimates (SU1), Canada (CA1) and United States (US1) also omit those northern strata. For the expanded survey area, estimates are provided for NWT, YT, NF, and BCRs 02 and 03 in AK for the time interval 1993-2022, and the regional estimates for the expanded area are devoted by SUR, CA and US. Producer defined ALA Alabama Producer defined AK Alaska Producer defined ARI Arizona Producer defined ARK Arkansas Producer defined BC British Columbia Producer defined CAL California Producer defined COL Colorado Producer defined CON Connecticut Producer defined DEL Delaware Producer defined FLA Florida Producer defined GA Georgia Producer defined IDA Idaho Producer defined ILL Illinois Producer defined IND Indiana Producer defined IA Iowa Producer defined KAN Kansas Producer defined KY Kentucky Producer defined LA Louisiana Producer defined ME Maine Producer defined MAN Manitoba Producer defined MD Maryland Producer defined MAS Massachusetts Producer defined MIC Michigan Producer defined MIN Minnesota Producer defined MIS Mississippi Producer defined MO Missouri Producer defined MON Mississippi Producer defined NEB Nebraska Producer defined NEV Nevada Producer defined NB Mississippi Producer defined NH New Hampshire Producer defined NJ New Jersey Producer defined NM New Mexico Producer defined NY New York Producer defined NC North Carolina Producer defined ND North Dakota Producer defined NS Nova Scotia Producer defined OHI Ohio Producer defined OKL Oklahoma Producer defined ONT Ontario Producer defined ORE Oregon Producer defined PA Pennsylvania Producer defined PEI Prince Edward Island Producer defined QUE Quebec Producer defined RI Rhode Island Producer defined SAS Saskachewan Producer defined SC South Carolina Producer defined SD South Dakota Producer defined TEN Tennessee Producer defined TEX Texas Producer defined UT Mississippi Producer defined VT Vermont Producer defined VA Virginia Producer defined WAS Wahsington Producer defined WV West Virginia Producer defined WIS Wisconsin Producer defined WYO Wyoming Producer defined S04 Northwestern Interior Forest Producer defined S05 Northern Pacific Rainforest Producer defined S06 Boreal Taiga Plains Producer defined S07 Taiga Shield and Hudson Plains Producer defined S08 Boreal Softwood Shield Producer defined S09 Great Basin Producer defined S10 Nothern Rockies Producer defined S11 Prairie Potholes Producer defined S12 Boreal Hardwood Transition Producer defined S13 Lower Great Lakes/ St. Lawrence Plain Producer defined S14 Atlantic Northern Forest Producer defined S15 Sierra Nevada Producer defined S16 Southern Rockies/Colorado Plateau Producer defined S17 Badlands and Prairies Producer defined S18 Shortgrass Prairie Producer defined S19 Central Mixed Grass Prairie Producer defined S20 Edwards Plateau Producer defined S21 Oaks and Prairies Producer defined S22 Eastern Tallgrass Prairie Producer defined S23 Prairie Hardwood Transition Producer defined S24 Central Hardwoods Producer defined S25 West Gulf Coastal Plain/Ouachitas Producer defined S26 Mississippi Alluvial Valley Producer defined S27 Southeastern Coastal Plain Producer defined S28 Appalachian Mountains Producer defined S29 Piedmont Producer defined S30 New England/Mid-Atlantic Coast Producer defined S31 Peninsular Florida Producer defined S32 Coastal California Producer defined S33 Sonoran and Mojave Deserts Producer defined S34 Sierra Madre Occidental Producer defined S35 Chihuahuan Desert Producer defined S36 Tamaulipan Brushlands Producer defined S37 Gulf Coastal Prairie Producer defined US United States Producer defined CAN Canada Producer defined SUR Survey-wide Producer defined US1 United States (core only) Producer defined CA1 Canada (core only) Producer defined SU1 Survey-wide (core only) Producer defined Region Name These are full names of the regions, and are presented in the trend results spreadsheets. See attribute "Region Code" for the regions included in care and expanded survey areas. Producer defined See also the BBS data metadata. AOU AOU numbers are 5 digit codes that represent bird species. These codes are defined to correspond to species and groups of species. See the Entity and Taxonomic sections for additional information. Some species data are aggregated due to taxonomic changes between 1966 - 2023; these groups are indexed by AOU numbers >30000. Listed by aggregated AOU and component AOU numbers (in parentheses): 31940 (01940 01920); 31320 (01320 01331)); 33370 (03370 03380); 36550 (06550 06560 06556); 35670 (05670 05660 05671 05690 05680 05677); 30010 (00010 00011 00012); 34120 (04120 04130 04123 04125); 34660 (04660 04661 04665); 34641 (04641 04640 04642); 35740 (05738 05739 05740)); 34880 (04880 04890 04882); 34810 (04810 04812 04813); 35010 (05010 05009 05011 05012). Common and scientific names of species are listed in the result spreadsheets. Producer defined See also the BBS data metadata for AOU numbers and species names. Note that some species that have been lumped or split by taxonomic authorities are aggregated for analysis. Species These are common names of bird species. See the taxonomy section for details on bird names. Producer defined See also the BBS data metadata for AOU numbers and species names Model This variable defines the statistical model used for the species. Model can take values "S" indicates the slope-random year effects model, "Sh" indicates the heavy-tailed slope-random year effects model, "D" indicates the difference model, and "Dh" indicates the heavy-tailed difference model. Producer defined S the slope-random year effects model Producer defined Sh the heavy-tailed slope-random year effects model, Producer defined D the difference model, and Producer defined Dh the heavy-tailed difference model. Producer defined Trend Trend estimates are calculated as the ratio of endpoints from the annual indices produced in the hierarchical model analysis. All trend estimates are produced using Bayesian methods, in which the posterior distributions of the parameter are computed, and the estimate is defined as the median of the posterior distribution. Both metrics are presented as a yearly percentage change. For ratio estimates for the core areas over the entire survey interval , the trends are computed from the first year in which data were collected in the region. Generally, for the eastern US (States E of the Mississippi), the BBS started in 1966; in the central US data were collected starting in 1967; and in the western US and Canada data collection started in 1968. Units: % Change/Year. Producer defined They are presented as a yearly percentage change. 2.5%CI These values represent the 2.5 percentiles of the posterior distribution of an estimate. These values replace the precision estimates and p values presented in earlier analyses, and taken with the 97.5%CI form a credible interval, or Bayesian confidence interval. If the credible interval does not contain 0, the result could be judged significant, and in these tables significant long-term results are indicated by red (for declining populations) or blue (for increasing populations) print. Results that are judged unreliable (red credibility index) are not highlighted by colors even if the CIs do not contain 0. Units: % Change/Year. Producer defined 2.5%CI can take any real value. 97.5%CI These values represent the 97.5 percentiles of the posterior distribution of an estimate. These values replace the precision estimates and p values presented in earlier analyses, and taken with the 2.5%CI form a credible Interval, or Bayesian confidence interval. If the credible interval does not contain 0, the result could be judged significant. Units: % Change/Year. Producer defined 97.5% CI can take any real value. N Routes This number represents the number of survey routes on which the species was encountered during the interval. A minor change was implemented in the counting of sample sizes for the 2015 analysis. 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 information to the analyses. The analysis has not changed; we only modified how we computed number of routes included in the analysis. Starting with the 2018 analysis, we corrected our sample size computation to exclude routes on which the species had been encountered only on a year in which the data were not admissible for the analysis. These data were never used in the analysis, but in earlier years those routes were included in the N routes on which the species occurred. They were excluded in this computation of N Routes. Producer defined A positive integer representing number of survey routes on which the species was encountered during the interval. Note that the N of routes for a region depends on criteria used for inclusion. In our analyses, we exclude replicate routes (and use the first survey when >1 survey is conducted within a year), and exclude routes that are "non-random" (i.e., routes with codes >900 that are surveyed in National Parks and other protected areas). We also exclude routes collected with non-standard protocols, with the exception of some routes conducted in the southern US that where analyzed in Sauer et al. (2018). Relative Abundance This value is the annual index for the region at the midpoint of the interval . The relative abundance estimate is model-based, produced as part of the hierarchical model analysis, and is adjusted for observer and other effects. We note that for some species (e.g., Tricolored Blackbirds and White-faced Ibis, the relative abundances are very large. This indicates that the annual indices for these species are very imprecisely estimated. Units: Birds/Route. Producer defined This value is the mean annual index for the region from the midyear of the trend interval. Relative abundance >= 0.001 Years Range of years that this trend covers. Producer Defined In most cases, the values for this range are one of three: 1966-2023, 1967-2023, or 1968-2023. These differences represent differences in when the BBS started in various parts of the core region, and correspond with whether 1966 and/or 1967 is NA in the core index file. In a few cases, the start year is later (up to 1983). BBS_Expanded_Trends_1993-2023.csv Trends for the interval 1993 - 2023 from an expanded BBS area and species list, computed using the ratio metric. Analysis for the expanded BBS area was initiated in 2015 to allow of incorporation of northern regions that contained very sparse data prior to 1993 (Sauer et al. 2017), and includes data from NWT, YT, NF, and BCRs 02 and 03 in AK. Summaries for the survey (SUR), the United States (US), and Canada (CA) contain results from this expanded area. Producer Defined Sample Size Code To facilitate review of species credibility, we include a separate indicator for the sample size component of the Credibility Measure: Producer defined R The sample is based on less than 5 routes for the long term, (very small samples) Producer defined Y The sample is based on less than 14 routes for the long term Producer defined blank The sample is based on at least 14 routes for the long term Producer defined Precision Code To facilitate review of species credibility, we include sub indicator for the precision component of the Credibility Measure Producer defined R "R" The results are so imprecise that a 5%/year change (as indicated by the half-width of the credible intervals) would not be detected over the long-term (very imprecise), Producer defined Y The results are so imprecise that a 3%/year change (as indicated by the half-width of the credible intervals) would not be detected over the long-term (quite imprecise), Producer defined blank The results are of sufficient precision that a 3%/year change (as indicated by the half-width of the credible intervals) would be detected over the long-term. Producer defined Abundance Code To facilitate review of species credibility, we include sub indicator for relative abundance component of the Credibility Measure Producer defined R The regional abundance is less than 0.1 birds/route (very low abundance), Producer defined Y The regional abundance is less than 1.0 birds/route (low abundance) Producer defined blank The regional abundance is at least 1.0 birds/route Producer defined Credibility Code Although the BBS provides a huge amount of information about regional population change for many species, there are a variety of possible problems with estimates of population change from BBS data. Small sample sizes, low relative abundances on survey routes, imprecise trends, and missing data all can compromise BBS results. In the complicated model fitting procedures presently used for the BBS, it is possible that convergence failures in regions with these deficiencies can produce results that are inaccurate as well as imprecise. Often, users do not take these problems into account when viewing BBS results, and use the results inappropriately. To provide some guidance to interpretation of BBS data, we have implemented a series of checks for some attributes that we view as cause for caution in interpretation of BBS results. Producer defined R (Red Indicator). This category reflects data with an important deficiency. In particular: 1. The regional abundance is less than 0.1 birds/route (very low abundance), 2. The sample is based on less than 5 routes for the long term (very small samples), or 3. The results are so imprecise that a 5%/year change (as indicated by the half-width of the credible intervals) would not be detected over the long-term (very imprecise). Users should be aware that a variety of circumstances may lead to imprecise results. For example, imprecise results are sometimes a consequence of a failure of the models to converge in those local areas, even though the model performs adequately in larger regions. Producer defined Y (Yellow Indicator). This category reflects data with a deficiency. In particular: 1. The regional abundance is less than 1.0 birds/route (low abundance), 2. The sample is based on less than 14 routes for the long term (small sample size), or 3. The results are so imprecise that a 3%/year change (as indicated by the half-width of the credible intervals) would not be detected over the long-term (quite imprecise) Producer defined blank (blank Indicator): This category reflects data with at least 14 samples in the long term, of moderate precision, and of moderate abundance on routes. Producer defined Significance An indicator variable that takes on value "1" if zero falls outside the 95% credible interval for the estimate and the trend estimate is > 0; "2" if zero falls outside the 95% credible interval for the estimate and the trend estimate is < 0; and " " (no value) if zero falls within the 95% credible interval. If the credible interval does not contain 0, the result could be judged significant. Producer defined 1 The 95% CI does not include 0 and the trend estimate is > 0. Producer defined blank 0 is inside the bounds of the CI Producer defined 2 The 95% CI does not include 0 and the trend estimate is < 0. Producer defined Region Region Codes consist of 3-character summary codes for State ID and state/province names, 3-character ID codes for Bird Conservation Regions (BCRs), and additional 3 character codes and names of larger regions such as countries and administrative regions for the Breeding Bird Survey. In the result spreadsheets for trends, the full names of the BCRs, state/provinces, and other regions are listed as well as a region code. The core BBS area (for which trends are computed from 1966-2022) does not include information from MWT, YT, NF, and BCRS 02 and 03 in AK, and the core areas survey-wide estimates (SU1), Canada (CA1) and United States (US1) also omit those northern strata. For the expanded survey area, estimates are provided for NWT, YT, NF, and BCRs 02 and 03 in AK for the time interval 1993-2022, and the regional estimates for the expanded area are devoted by SUR, CA and US. Producer defined ALA Alabama Producer defined AK Alaska Producer defined ARI Arizona Producer defined ARK Arkansas Producer defined BC British Columbia Producer defined CAL California Producer defined COL Colorado Producer defined CON Connecticut Producer defined DEL Delaware Producer defined FLA Florida Producer defined GA Georgia Producer defined IDA Idaho Producer defined ILL Illinois Producer defined IND Indiana Producer defined IA Iowa Producer defined KAN Kansas Producer defined KY Kentucky Producer defined LA Louisiana Producer defined ME Maine Producer defined MAN Manitoba Producer defined MD Maryland Producer defined MAS Massachusetts Producer defined MIC Michigan Producer defined MIN Minnesota Producer defined MIS Mississippi Producer defined MO Missouri Producer defined MON Mississippi Producer defined NEB Nebraska Producer defined NEV Nevada Producer defined NB Mississippi Producer defined NH New Hampshire Producer defined NJ New Jersey Producer defined NM New Mexico Producer defined NY New York Producer defined NC North Carolina Producer defined ND North Dakota Producer defined NS Nova Scotia Producer defined OHI Ohio Producer defined OKL Oklahoma Producer defined ONT Ontario Producer defined ORE Oregon Producer defined PA Pennsylvania Producer defined PEI Prince Edward Island Producer defined QUE Quebec Producer defined RI Rhode Island Producer defined SAS Saskachewan Producer defined SC South Carolina Producer defined SD South Dakota Producer defined TEN Tennessee Producer defined TEX Texas Producer defined UT Mississippi Producer defined VT Vermont Producer defined VA Virginia Producer defined WAS Wahsington Producer defined WV West Virginia Producer defined WIS Wisconsin Producer defined WYO Wyoming Producer defined S04 Northwestern Interior Forest Producer defined S05 Northern Pacific Rainforest Producer defined S06 Boreal Taiga Plains Producer defined S07 Taiga Shield and Hudson Plains Producer defined S08 Boreal Softwood Shield Producer defined S09 Great Basin Producer defined S10 Nothern Rockies Producer defined S11 Prairie Potholes Producer defined S12 Boreal Hardwood Transition Producer defined S13 Lower Great Lakes/ St. Lawrence Plain Producer defined S14 Atlantic Northern Forest Producer defined S15 Sierra Nevada Producer defined S16 Southern Rockies/Colorado Plateau Producer defined S17 Badlands and Prairies Producer defined S18 Shortgrass Prairie Producer defined S19 Central Mixed Grass Prairie Producer defined S20 Edwards Plateau Producer defined S21 Oaks and Prairies Producer defined S22 Eastern Tallgrass Prairie Producer defined S23 Prairie Hardwood Transition Producer defined S24 Central Hardwoods Producer defined S25 West Gulf Coastal Plain/Ouachitas Producer defined S26 Mississippi Alluvial Valley Producer defined S27 Southeastern Coastal Plain Producer defined S28 Appalachian Mountains Producer defined S29 Piedmont Producer defined S30 New England/Mid-Atlantic Coast Producer defined S31 Peninsular Florida Producer defined S32 Coastal California Producer defined S33 Sonoran and Mojave Deserts Producer defined S34 Sierra Madre Occidental Producer defined S35 Chihuahuan Desert Producer defined S36 Tamaulipan Brushlands Producer defined S37 Gulf Coastal Prairie Producer defined US United States Producer defined CAN Canada Producer defined SUR Survey-wide Producer defined US1 United States (core only) Producer defined CA1 Canada (core only) Producer defined SU1 Survey-wide (core only) Producer defined Region Name These are full names of the regions, and are presented in the trend results spreadsheets. See attribute "Region Code" for the regions included in care and expanded survey areas. Producer defined See also the BBS data metadata. AOU AOU numbers are 5 digit codes that represent bird species. These codes are defined to correspond to species and groups of species. See the Entity and Taxonomic sections for additional information. Some species data are aggregated due to taxonomic changes between 1966 - 2023; these groups are indexed by AOU numbers >30000. Listed by aggregated AOU and component AOU numbers (in parentheses): 31940 (01940 01920); 31320 (01320 01331)); 33370 (03370 03380); 36550 (06550 06560 06556); 35670 (05670 05660 05671 05690 05680 05677); 30010 (00010 00011 00012); 34120 (04120 04130 04123 04125); 34660 (04660 04661 04665); 34641 (04641 04640 04642); 34120 (04120 04130 04123 04125); 35740 (05738 05739 05740)); 34880 (04880 04890 04882); 35010 (05009 05010 05011 05012). Common and scientific names of species are listed in the result spreadsheets. Producer defined See also the BBS data metadata for AOU numbers and species names. Note that some species that have been lumped or split by taxonomic authorities are aggregated for analysis. Species These are common names of bird species. See the taxonomy section for details on bird names. Producer defined See also the BBS data metadata for AOU numbers and species names Model This variable defines the statistical model used for the species. Model can take values "S" indicates the slope-random year effects model, "Sh" indicates the heavy-tailed slope-random year effects model, "D" indicates the difference model, and "Dh" indicates the heavy-tailed difference model. Producer defined S the slope-random year effects model Producer defined Sh the heavy-tailed slope-random year effects model Producer defined D the difference model Producer defined Dh the heavy-tailed difference model. Producer defined Trend Trend estimates are calculated as the ratio of endpoints from the annual indices produced in the hierarchical model analysis. All trend estimates are produced using Bayesian methods, in which the posterior distributions of the parameter are computed, and the estimate is defined as the median of the posterior distribution. Both metrics are presented as a yearly percentage change. Units: % Change/Year. Producer defined They are presented as a yearly percentage change. 2.5%CI These values represent the 2.5 percentiles of the posterior distribution of an estimate. These values replace the precision estimates and p values presented in earlier analyses, and taken with the 97.5%CI form a credible interval, or Bayesian confidence interval. If the credible interval does not contain 0, the result could be judged significant, and in these tables significant long-term results are indicated by red (for declining populations) or blue (for increasing populations) print. Results that are judged unreliable (red credibility index) are not highlighted by colors even if the CIs do not contain 0. Units: % Change/Year. Producer defined 2.5%CI can take any real value. 97.5%CI These values represent the 97.5 percentiles of the posterior distribution of an estimate. These values replace the precision estimates and p values presented in earlier analyses, and take n with the 2.5%CI form a credible Interval, or Bayesian confidence interval. If the credible interval does not contain 0, the result could be judged significant. Units: % Change/Year. Producer defined 97.5% CI can take any real value. N Routes This number represents the number of survey routes on which the species was encountered during the interval. A minor change was implemented in the counting of sample sizes for the 2015 analysis. 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 information to the analyses. The analysis has not changed; we only modified how we computed number of routes included in the analysis. Starting with the 2018 analysis, we corrected our sample size computation to exclude routes on which the species had been encountered only on a year in which the data were not admissible for the analysis. These data were never used in the analysis, but in earlier years those routes were included in the N routes on which the species occurred. They were excluded in this computation of N Routes. Producer defined A positive integer representing number of survey routes on which the species was encountered during the interval. Note that the N of routes for a region depends on criteria used for inclusion. In our analyses, we exclude replicate routes (and use the first survey when >1 survey is conducted within a year), and exclude routes that are "non-random" (i.e., routes with codes >900 that are surveyed in National Parks and other protected areas). We also exclude routes collected with non-standard protocols, with the exception of some routes conducted in the southern US that were analyzed in Sauer et al. (2018). Relative Abundance This value is the annual index for the region for at the midpoint of the interval. The relative abundance estimate is model-based, produced as part of the hierarchical model analysis, and is adjusted for observer and other effects. We note that for some species (e.g., Tricolored Blackbirds and White-faced Ibis, the relative abundances are very large. This indicates that the annual indices for these species are very imprecisely estimated. Units: Birds/Route. Producer defined This value is the annual index for the region from the midyear of the trend interval. Relative abundance >= 0.001 BBS_Core_Indices_1966-2023.csv Annual indices for 1966(83) - 2023 from the core area. These are yearly indexes of abundance estimated using a hierarchical model analysis for regions corresponding to the long-term ratio trend estimates (1). Producer Defined Region Region Codes consist of 3-character summary codes for State ID and state/province names, 3-character ID codes for Bird Conservation Regions (BCRs), and additional 3 character codes and names of larger regions such as countries and administrative regions for the Breeding Bird Survey. In the result spreadsheets for trends, the full names of the BCRs, state/provinces, and other regions are listed as well as a region code. The core BBS area (for which trends are computed from 1966-2022) does not include information from MWT, YT, NF, and BCRS 02 and 03 in AK, and the core areas survey-wide estimates (SU1), Canada (CA1) and United States (US1) also omit those northern strata. For the expanded survey area, estimates are provided for NWT, YT, NF, and BCRs 02 and 03 in AK for the time interval 1993-2022, and the regional estimates for the expanded area are devoted by SUR, CA and US. Producer defined ALA Alabama Producer defined AK Alaska Producer defined ARI Arizona Producer defined ARK Arkansas Producer defined BC British Columbia Producer defined CAL California Producer defined COL Colorado Producer defined CON Connecticut Producer defined DEL Delaware Producer defined FLA Florida Producer defined GA Georgia Producer defined IDA Idaho Producer defined ILL Illinois Producer defined IND Indiana Producer defined IA Iowa Producer defined KAN Kansas Producer defined KY Kentucky Producer defined LA Louisiana Producer defined ME Maine Producer defined MAN Manitoba Producer defined MD Maryland Producer defined MAS Massachusetts Producer defined MIC Michigan Producer defined MIN Minnesota Producer defined MIS Mississippi Producer defined MO Missouri Producer defined MON Mississippi Producer defined NEB Nebraska Producer defined NEV Nevada Producer defined NB Mississippi Producer defined NH New Hampshire Producer defined NJ New Jersey Producer defined NM New Mexico Producer defined NY New York Producer defined NC North Carolina Producer defined ND North Dakota Producer defined NS Nova Scotia Producer defined OHI Ohio Producer defined OKL Oklahoma Producer defined ONT Ontario Producer defined ORE Oregon Producer defined PA Pennsylvania Producer defined PEI Prince Edward Island Producer defined QUE Quebec Producer defined RI Rhode Island Producer defined SAS Saskachewan Producer defined SC South Carolina Producer defined SD South Dakota Producer defined TEN Tennessee Producer defined TEX Texas Producer defined UT Mississippi Producer defined VT Vermont Producer defined VA Virginia Producer defined WAS Wahsington Producer defined WV West Virginia Producer defined WIS Wisconsin Producer defined WYO Wyoming Producer defined S04 Northwestern Interior Forest Producer defined S05 Northern Pacific Rainforest Producer defined S06 Boreal Taiga Plains Producer defined S07 Taiga Shield and Hudson Plains Producer defined S08 Boreal Softwood Shield Producer defined S09 Great Basin Producer defined S10 Nothern Rockies Producer defined S11 Prairie Potholes Producer defined S12 Boreal Hardwood Transition Producer defined S13 Lower Great Lakes/ St. Lawrence Plain Producer defined S14 Atlantic Northern Forest Producer defined S15 Sierra Nevada Producer defined S16 Southern Rockies/Colorado Plateau Producer defined S17 Badlands and Prairies Producer defined S18 Shortgrass Prairie Producer defined S19 Central Mixed Grass Prairie Producer defined S20 Edwards Plateau Producer defined S21 Oaks and Prairies Producer defined S22 Eastern Tallgrass Prairie Producer defined S23 Prairie Hardwood Transition Producer defined S24 Central Hardwoods Producer defined S25 West Gulf Coastal Plain/Ouachitas Producer defined S26 Mississippi Alluvial Valley Producer defined S27 Southeastern Coastal Plain Producer defined S28 Appalachian Mountains Producer defined S29 Piedmont Producer defined S30 New England/Mid-Atlantic Coast Producer defined S31 Peninsular Florida Producer defined S32 Coastal California Producer defined S33 Sonoran and Mojave Deserts Producer defined S34 Sierra Madre Occidental Producer defined S35 Chihuahuan Desert Producer defined S36 Tamaulipan Brushlands Producer defined S37 Gulf Coastal Prairie Producer defined US United States Producer defined CAN Canada Producer defined SUR Survey-wide Producer defined US1 United States (core only) Producer defined CA1 Canada (core only) Producer defined SU1 Survey-wide (core only) Producer defined AOU AOU numbers are 5 digit codes that represent bird species. These codes are defined to correspond to species and groups of species. See the Entity and Taxonomic sections for additional information. Some species data are aggregated due to taxonomic changes between 1966 - 2023; these groups are indexed by AOU numbers >30000. Listed by aggregated AOU and component AOU numbers (in parentheses): 31940 (01940 01920); 31320 (01320 01331)); 33370 (03370 03380); 36550 (06550 06560 06556); 35670 (05670 05660 05671 05690 05680 05677); 30010 (00010 00011 00012); 34120 (04120 04130 04123 04125); 34660 (04660 04661 04665); 34641 (04641 04640 04642); 34120 (04120 04130 04123 04125); 35740 (05738 05739 05740)); 34880 (04880 04890 04882); 35010 (05009 05010 05011 05012). Common and scientific names of species are listed in the result spreadsheets. Producer defined See also the BBS data metadata for AOU numbers and species names. Year Calender year associated with index value Producer defined 1966 2023 Year Index Annual indexes (Index) are relative abundance estimates for all years, estimated as yearly predicted abundances from the hierarchical model analysis. See Sauer and Link (2011, p. 89, col 2, para 4) for a precise definition of the indexes; a qualitative description of them is that they represent the mean count of birds on a typical route in the region for a year. We note that for some species (e.g., Tricolored Blackbirds and White-faced Ibis), the annual indices are very large. This indicates that the indices for these species are very imprecisely estimated. Units: Birds/Route. Producer defined NA Inadmissible values Producer defined Annual indexes are relative abundance estimates for all years, estimated as yearly predicted abundances from the hierarchical model analysis. Indexes are >=0. Values "NA" occur in 1966, 1967, and other early years (up to 1982) when no surveys were conducted in a year corresponding to the index for that region. Note that the survey was not conducted in 2020 due to pandemic restrictions. Annual indexes and CIs listed for 2020 are interpolations of adjacent data produced by the hierarchical model. 2.5%CI These values represent the 2.5 percentiles of the posterior distribution of an estimate. These values replace the precision estimates and p values presented in earlier analyses, and taken with the 97.5%CI form a credible interval, or Bayesian confidence interval. If the credible interval does not contain 0, the result could be judged significant, and in these tables significant long-term results are indicated by red (for declining populations) or blue (for increasing populations) print. Results that are judged unreliable (red credibility index) are not highlighted by colors even if the CIs do not contain 0. Units: Birds/Route. Producer defined NA Inadmissible values Producer defined 2.5%CI can take any non-negative value. For CIs of index esitmates, values "NA" occur in 1966, 1967, and other early years (up to 1982) when no surveys were conducted in a year corresponding to the index for that region. Note that the survey was not conducted in 2020 due to pandemic restrictions. Annual indexes listed for 2020 are interpolations of adjacent data produced by the hierarchical model. 97.5%CI These values represent the 97.5 percentiles of the posterior distribution of an estimate. These values replace the precision estimates and p values presented in earlier analyses, and taken with the 2.5%CI form a credible Interval, or Bayesian confidence interval. If the credible interval does not contain 0, the result could be judged significant. Units: Birds/Route Producer defined NA Inadmissible values Producer defined 97.5%CI can take any real value, but may be truncated for convenience if abs(value) >999. For CIs of index estimates, values "NA" occur in 1966, 1967, and other early years (up to 1982) when no surveys were conducted in a year corresponding to the index for that region. We note that for some species (e.g., Tricolored Blackbirds and White-faced Ibis), the 97.5%CI are very large. This indicates that the indices for these species are very imprecisely estimated. Note that the survey was not conducted in 2020 due to pandemic restrictions. Annual indexes listed for 2020 are interpolations of adjacent data produced by the hierarchical model. BBS_Expanded_Indices_1993-2023.csv Annual indices from 1993 - 2023 for the expanded area. These are yearly indexes of abundance estimated using a hierarchical model analysis for regions corresponding to the 1993 - 2023 ratio trend estimates (3). Producer Defined Region Region Codes consist of 3-character summary codes for State ID and state/province names, 3-character ID codes for Bird Conservation Regions (BCRs), and additional 3 character codes and names of larger regions such as countries and administrative regions for the Breeding Bird Survey. In the result spreadsheets for trends, the full names of the BCRs, state/provinces, and other regions are listed as well as a region code. The core BBS area (for which trends are computed from 1966-2022) does not include information from MWT, YT, NF, and BCRS 02 and 03 in AK, and the core areas survey-wide estimates (SU1), Canada (CA1) and United States (US1) also omit those northern strata. For the expanded survey area, estimates are provided for NWT, YT, NF, and BCRs 02 and 03 in AK for the time interval 1993-2022, and the regional estimates for the expanded area are devoted by SUR, CA and US. Producer defined ALA Alabama Producer defined AK Alaska Producer defined ARI Arizona Producer defined ARK Arkansas Producer defined BC British Columbia Producer defined CAL California Producer defined COL Colorado Producer defined CON Connecticut Producer defined DEL Delaware Producer defined FLA Florida Producer defined GA Georgia Producer defined IDA Idaho Producer defined ILL Illinois Producer defined IND Indiana Producer defined IA Iowa Producer defined KAN Kansas Producer defined KY Kentucky Producer defined LA Louisiana Producer defined ME Maine Producer defined MAN Manitoba Producer defined MD Maryland Producer defined MAS Massachusetts Producer defined MIC Michigan Producer defined MIN Minnesota Producer defined MIS Mississippi Producer defined MO Missouri Producer defined MON Mississippi Producer defined NEB Nebraska Producer defined NEV Nevada Producer defined NB Mississippi Producer defined NH New Hampshire Producer defined NJ New Jersey Producer defined NM New Mexico Producer defined NY New York Producer defined NC North Carolina Producer defined ND North Dakota Producer defined NS Nova Scotia Producer defined OHI Ohio Producer defined OKL Oklahoma Producer defined ONT Ontario Producer defined ORE Oregon Producer defined PA Pennsylvania Producer defined PEI Prince Edward Island Producer defined QUE Quebec Producer defined RI Rhode Island Producer defined SAS Saskachewan Producer defined SC South Carolina Producer defined SD South Dakota Producer defined TEN Tennessee Producer defined TEX Texas Producer defined UT Mississippi Producer defined VT Vermont Producer defined VA Virginia Producer defined WAS Wahsington Producer defined WV West Virginia Producer defined WIS Wisconsin Producer defined WYO Wyoming Producer defined S04 Northwestern Interior Forest Producer defined S05 Northern Pacific Rainforest Producer defined S06 Boreal Taiga Plains Producer defined S07 Taiga Shield and Hudson Plains Producer defined S08 Boreal Softwood Shield Producer defined S09 Great Basin Producer defined S10 Nothern Rockies Producer defined S11 Prairie Potholes Producer defined S12 Boreal Hardwood Transition Producer defined S13 Lower Great Lakes/ St. Lawrence Plain Producer defined S14 Atlantic Northern Forest Producer defined S15 Sierra Nevada Producer defined S16 Southern Rockies/Colorado Plateau Producer defined S17 Badlands and Prairies Producer defined S18 Shortgrass Prairie Producer defined S19 Central Mixed Grass Prairie Producer defined S20 Edwards Plateau Producer defined S21 Oaks and Prairies Producer defined S22 Eastern Tallgrass Prairie Producer defined S23 Prairie Hardwood Transition Producer defined S24 Central Hardwoods Producer defined S25 West Gulf Coastal Plain/Ouachitas Producer defined S26 Mississippi Alluvial Valley Producer defined S27 Southeastern Coastal Plain Producer defined S28 Appalachian Mountains Producer defined S29 Piedmont Producer defined S30 New England/Mid-Atlantic Coast Producer defined S31 Peninsular Florida Producer defined S32 Coastal California Producer defined S33 Sonoran and Mojave Deserts Producer defined S34 Sierra Madre Occidental Producer defined S35 Chihuahuan Desert Producer defined S36 Tamaulipan Brushlands Producer defined S37 Gulf Coastal Prairie Producer defined US United States Producer defined CAN Canada Producer defined SUR Survey-wide Producer defined US1 United States (core only) Producer defined CA1 Canada (core only) Producer defined SU1 Survey-wide (core only) Producer defined AOU AOU numbers are 5 digit codes that represent bird species. These codes are defined to correspond to species and groups of species. See the Entity and Taxonomic sections for additional information. Some species data are aggregated due to taxonomic changes between 1966 - 2023; these groups are indexed by AOU numbers >30000. Listed by aggregated AOU and component AOU numbers (in parentheses): 31940 (01940 01920); 31320 (01320 01331)); 33370 (03370 03380); 36550 (06550 06560 06556); 35670 (05670 05660 05671 05690 05680 05677); 30010 (00010 00011 00012); 34120 (04120 04130 04123 04125); 34660 (04660 04661 04665); 34641 (04641 04640 04642); 34120 (04120 04130 04123 04125); 35740 (05738 05739 05740); 34880 (04880 04890 04882); 35010 (05010 05009 05011 05012). Common and scientific names of species are listed in the result spreadsheets. Producer defined See also the BBS data metadata for AOU numbers and species names Year Calender year associated with index value Producer defined 1993 2023 Year Index Annual indexes (Index) are relative abundance estimates for all years, estimated as yearly predicted abundances from the hierarchical model analysis. See Sauer and Link (2011, p. 89, col 2, para 4) for a precise definition of the indexes; a qualitative description of them is that they represent the mean count of birds on a typical route in the region for a year. We note that for some species (e.g., Tricolored Blackbirds and White-faced Ibis), the annual indices are very large. This indicates that the indices for these species are very imprecisely estimated. Units: Birds/Route Producer defined Annual indexes are relative abundance estimates for all years, estimated as yearly predicted abundances from the hierarchical model analysis. Indexes are >=0. Note that the survey was not conducted in 2020 due to pandemic restrictions. Annual indexes listed for 2020 are interpolations of adjacent data produced by the hierarchical model. 2.5%CI These values represent the 2.5 percentiles of the posterior distribution of an estimate. These values replace the precision estimates and p values presented in earlier analyses, and taken with the 97.5%CI form a credible interval, or Bayesian confidence interval. If the credible interval does not contain 0, the result could be judged significant, and in these tables significant long-term results are indicated by red (for declining populations) or blue (for increasing populations) print. Results that are judged unreliable (red credibility index) are not highlighted by colors even if the CIs do not contain 0. Units: Birds/Route Producer defined 2.5%CI can take any real value, but may be truncated for convenience if abs(value) >999. Note that the survey was not conducted in 2020 due to pandemic restrictions. Annual indexes listed for 2020 are interpolations of adjacent data produced by the hierarchical model. 97.5%CI These values represent the 97.5 percentiles of the posterior distribution of an estimate. These values replace the precision estimates and p values presented in earlier analyses, and taken with the 2.5%CI form a credible Interval, or Bayesian confidence interval. If the credible interval does not contain 0, the result could be judged significant. Units: Birds/Route. Producer defined NA Inadmissable values Producer defined 97.5 CI can take any real value, but may be truncated for convenience if abs(value) >999. Note that the survey was not conducted in 2020 due to pandemic restrictions. Annual indexes listed for 2020 are interpolations of adjacent data produced by the hierarchical model. These data files and associated web-based summary programs are designed to provide public access to analysis results from BBS data. Primary results are provided in spreadsheet form, and are described in this metadata. Results are presented in 4 spreadsheets: 1. Long-term trends (1966[68] - 2023) from the BBS core area using Link and Sauer (2002) definition of trend as a ratio of endpoints of annual indices. (Spreadsheet name: BBS_Core_Trends_1966-2023.csv). The core area is the region used for BBS analyses in prior years (e.g., Sauer and Link 2011), and omits NWT, YT, NF, and portion of AK (BCRs 02 and 03), but includes the core area survey estimates (SU1), the contiguous United States (US1), and portions of Canada in the core area (CA1). Starting year varies from 1966-1968 [1966(68)], depending on region. 2. Trends for the interval 1993 - 2022 from an expanded BBS area and species list, computed using the ratio metric. Analysis for the expanded BBS area was initiated in 2015 to allow of incorporation of northern regions that contained very sparse data prior to 1993 (Sauer et al. 2017), and includes data from NWT, YT, NF, and BCRs 02 and 03 in AK. Summaries for the survey (SUR), the United States (US), and Canada (CA) contain results from this expanded area. (Spreadsheet name: BBS_Expanded_Trends_1993-2023.csv) 3. Annual indices for 1966(68) - 2022 from the core area. These are yearly indexes of abundance estimated using a hierarchical model analysis for regions corresponding to the long-term ratio trend estimates (1). (Spreadsheet: BBS_Core_Indices_1966-2023.csv) 4. Annual indices from 1993 - 2022 for the expanded area. These are yearly indexes of abundance estimated using a hierarchical model analysis for regions corresponding to the 1993 - 2023 ratio trend estimates (3).(Spreadsheet: BBS_Expanded_Indices_1993-2023.csv). The North American Breeding Bird Survey, Analysis Results 1966 - 2023 U.S. Geological Survey - ScienceBase mailing address

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Denver CO 80225 1-888-275-8747 sciencebase@usgs.gov "Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty." "This database, identified as North American Breeding Bird Survey Analysis Results 1966 - 2023, has been approved for release by the U.S. Geological Survey (USGS). Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, the database is released on condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from its authorized or unauthorized use." Digital Data https://doi.org/10.5066/P1F2X4WH None. 20250225 Jeffrey A. Hostetler US Geological Survey, Eastern Ecological Science Center Research Biologist mailing address

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Laurel MD 20708 United States 301-497-5662 301-497-5666 jhostetler@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999