The latest BBS report includes an annual update of population trends, specifically along waterways, for 24 species with the strongest association with that habitat type. These trends are repeated in the table below. Trends are derived from the entire WBBS data sets, and date back to 1999.
The trends below are taken from the latest Breeding Bird Survey Report.
See BirdTrends for details of methodology and a discussion of each species' results in a wider context.
This tables shows percentage changes in bird populations during the specified period.
Trends are marked with an asterisk (*) where the 95% confidence limits of the change do not overlap zero (indicating that there has been a significant change).
The trend since the start of the survey, covering the years 1998–2017, has been smoothed, and the end years truncated. This trend is labelled as Change 99–16.
The sample is the mean number of squares per year on which the species was recorded during 1998–2017.
LCL and UCL are the lower and upper 95% confidence limits for the 1999–2016 change.
Trends for species in brackets are reported with caveats: Cormorant, Grey Heron and Common Tern are reported with the caveat that counts may contain a high proportion of birds away from breeding sites.