Results

The main annual output from WBBS is a set of trends showing how the population sizes of the various species have changed. For up to 25 waterway-specialist species, trends are compiled using both WBS and WBBS data and use results from as early as 1974. These trends are included in the species pages of the Birdtrends report, often as the headline trend.  Direct access to all of the trends from waterways surveys in this report is available through its table generator.

The most striking long-term changes derived from WBS/WBBS results are the decreases among waders, especially Snipe, Redshank, Common Sandpiper and Lapwing, and the loss of more than 90% of Yellow Wagtails since the surveys began. The species showing the greatest increases on WBBS stretches are the wildfowl, including Greylag and Canada Geese, Mallard, Goosander and Tufted Duck.

Results for mammals, analysed alongside those from BBS, have helped to document changes such as the decrease of Water Voles.