Phenology effects in the North American Breeding Bird Survey

This data product provides summary information, by species, of changes in relative visibility of birds (phenology effects) through the April - July time period in which the North American Breeding Bird Survey (BBS) is conducted. Data are presented for 408 species of birds. Seasonal 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 csv files, stored in zip files by first letter of the species common name and a single zip file containing csv files for 408 species.  Links are provided to Child Items containing additional information in species-specific R data sets and graphics in species-specific pdf files.