Breeding Bird Survey results

Introduction

This website provides detailed population trend information based on data collected through the North American Breeding Bird Survey (BBS), for approximately 300 Canadian bird species. The trend results presented here are for Canadian regions only, however data from the full BBS survey are used in the analyses. If users would like to access the full survey-wide results from this model, please contact bbs@ec.gc.ca. Trends are presented for species, provinces, territories and Bird Conservation Regions for which there are sufficient BBS data for statistical analysis.

The BBS is jointly coordinated by Environment Canada and the U.S. Geological Survey (USGS), Eastern Ecological Science Center. Any use of these BBS results for Canada should acknowledge the hundreds of skilled volunteers in Canada who have participated in the BBS over the years and those who have served as provincial or territorial coordinators for the BBS.

Please visit the Status of Birds in Canada web site for a comprehensive assessment of the population and conservation status of most species that breed in Canada, which considers BBS results as well as results from other relevant surveys. For waterfowl, comprehensive assessments are available in the most recent report on the Population Status of Migratory Game Birds in Canada.

New aspects of the analysis in this version

We continually strive to improve the population trend estimates from the BBS.

These estimates were produced using a new spatially explicit statistical model that tracks changes in populations through time with a non-linear smoothing function and year effects (Generalized Additive Model with Year Effects, "GAMYE"). This model was developed to better track non-linear changes in species populations, such as population cycles due to natural climatic processes or change points where populations begin to decline or to recover from earlier declines. The spatially explicit components were developed to improve estimates of population change in each region by sharing information on trends in neighbouring regions. This local sharing of information improves both the local estimates and the overall estimates of change. A full description of the GAMYE model and the spatially explicit versions is freely available in two articles published in the journal Ornithological Applications (Smith and Edwards, 2020), and Smith et al. 2024).

For each species, the same spatial regions of the country are included in both short-and long-term population trends. In previous versions of these estimates, some regions were excluded from the long-term trends if there were no local data in the early portion of the time series. The new model includes parameters that allow the population trajectory from regions with data missing from some portion of the time series to be estimated based on information from other regions of the species’ range, and so it is no longer necessary to remove these regions from the calculation of long-term trends. We have redefined the reliability metric “local data weight” to identify regions where the data may be missing from the early portion of the time series and to indicate the relative importance of these missing data.

Finally, the maps that show the spatial regions included in each trend estimate are now coloured to also show the population trend in each region. Cool colours(blues) indicate increasing trends and warm colours(reds) indicate decreasing trends.

Visit the BBS statistical methods page for more information on the statistical methods used to produce these trends, annual indices and credibility measures.

View trends and annual indices

• View Breeding Bird Survey trends by selecting a species
• View Breeding Bird Survey trends by selecting a geographical region

Download all trends and annual indices

Select a link below to download all Breeding Bird Survey trend results or annual indices as comma delimited text files. Note: Similar files specific to a given species or region are available for download through the 'View trends and annual indices' options above.

• Download trend results for all species, regions and time periods (*.csv, 4.5 MB)
• Download annual indices for all species, regions and time periods (*.csv, 48.1 MB)

Please send enquiries about the Breeding Bird Survey in Canada to: bbs.ec@canada.ca

This web site may be cited as: Smith, A.C., Hudson, M-A.R. Aponte, V.I., English, W.B., and Francis, C.M. 2024. North American Breeding Bird Survey - Canadian Trends Website, Data-version 2023. Environment and Climate Change Canada, Gatineau, Quebec, K1A 0H3

Any use of these BBS results for Canada should acknowledge the hundreds of skilled volunteers in Canada who have participated in the BBS over the years and those who have served as provincial or territorial coordinators for the BBS.

1. Smith, A. C., & Edwards, B. P. M. (2020). North American Breeding Bird Survey status and trend estimates to inform a wide range of conservation needs, using a flexible Bayesian hierarchical generalized additive model. The Condor, duaa065. https://doi.org/10.1093/ornithapp/duaa065
2. Smith, A. C., A. D. Binley, L. Daly, B. P. M. Edwards, D. Ethier, B. Frei, D. Iles, T. D. Meehan, N. L. Michel, and P. A. Smith. (2024). Spatially explicit Bayesian hierarchical models improve estimates of avian population status and trends. Ornithological Applications 126:duad056. https://doi.org/10.1093/ornithapp/duad056.