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Phenology effects in the North American Breeding Bird Survey - Results by species in .rdata format


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Sauer, J.R., and Link, W.A., 2022, Phenology effects in the North American Breeding Bird Survey: US Geological Survey data release,


This data product provides summary information of changes in relative visibility of 408 species of North American birds (phenology effects) through the April - July time period in which the North American Breeding Bird Survey (BBS) is conducted. These phenology effects are presented for selected latitudes and years, documenting changes in visibility and a variety of statistics to allow users to assess the significance of those effects. Results are presented as R data sets as supplemental material to primary results presented as csv files.


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Results rdata
“Results for 408 species in format read by Program R (rdata)”
55.58 MB application/zip


Phenology effects in birds are currently of great scientific interest, as they may reflect the "thumbprint" of climate change. Migrant birds are thought to be arriving earlier on breeding grounds, and it is thought that changes in climate (earlier onset spring and warmer summers) are influencing bird population dynamics through effects on breeding and survival. Documenting whether bird species are changing the timing of breeding activity is essential to increasing our understanding of climate effects on birds, and the BBS is a primary source of information on bird activity during the breeding season. Changes in bird phenology might also be influencing our estimates of bird population change, by decreasing counts due to phenological effects rather than to actual population change. We implemented an innovative new approach for modeling changes in bird activity through the breeding season with BBS data; these changes in bird activity are likely reflecting changes in breeding activity. Models were implemented for 408 species; data files presented here document change for each species for a sample of years and latitudes that provide information that can be used to evaluate temporal and spatial changes in phenology. See the North American Breeding Bird Survey Dataset ( for information on the most recent data release from the BBS. The BBS is hosted by the Eastern Ecological Science Center (EESC, Primary results are described in this metadata for rdata files. The csv files presented in Sciencebase Data Release "Phenology effects in the North American Breeding Bird Survey" were extracted from these rdata files. See the Process Step in the Data Quality tab to see the code used to produce the csv files. These results are based on modified versions of 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 ( Standard disclaimers for use of information are also provided (



  • Eastern Ecological Science Center



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