About WBBS

The Waterways Breeding Bird Survey began in 1998 and has become an ongoing annual survey. Around 250–300 river and canal sites are now surveyed each year for breeding birds by the BTO's volunteer observers.

Sites for coverage have mostly been selected randomly. The WBBS sample also includes around 60 former WBS sites where there has been a long history of mapping and transect coverage. These 'WBS-linked' sites provide a high degree of continuity between WBS and the current survey that replaces it.

WBBS stretches vary in length between one and ten 500-m transect sections, depending on the nature of the site and on the access that is available. Most stretches are 3–4 km in length. The transect section length is set at 500 m to match that of the Environment Agency’s River Habitat Survey (RHS).