Annual seabird productivity at breeding colonies around the world from 1964 to 2023 (Stratification Impacts on Seabirds Project)

This global dataset on breeding productivity represents a compilation of individual time series from species and sites (seabird breeding colonies) across the world. Each time series was contributed by a Global Seabird Working Group (GSWG) collaborator. It contains the number of offspring produced per nesting female per year, which is a variable measured similarly by researchers. Seabird breeding productivity is typically measured by monitoring individual nest sites through time within each breeding season. Data from multiple females are then averaged to produce estimates of annual productivity for each species at each site, resulting in “species-site” time series. Typically, measurements are made for multiple species at each site, so data are often available for a portion of the full seabird community, including species feeding at different trophic levels and in different parts of the water column. Variance for species-site breeding productivity is estimated as the standard error across years for each time series. Here, there are 202 time series encompassing 87 sites and 73 seabird species.