Bird Count Data
Bird count data is collected as part of the Wetland Bird Survey (WeBS). WeBS is a joint scheme of the British Trust for Ornithology, the Wildfowl and Wetlands Trust, Royal Society for the Protection of Birds and the Joint Nature Conservation Committee. The scheme aims to provide a scientific basis for the conservation of waterbird populations.
The counts form two types: core counts which are undertaken once a month on pre-selected dates around the winter period (normally) at high tide. Low tide counts are conducted at low tide on most estuaries around once every six years, with up to four counts being made.
Core count data is available for the entire study area for the period 1999/00 - 2003/04, and low tide data is available for the period 2002/2003. A very good coverage of bird data is available for the study area from these sources. For the purposes of this study, core count data has been obtained for the Thames Estuary and Marshes SPA for the period 1998/99 – 2002/03 (East Tilbury Jetty ES, 2005) and for the period 1995/96 – 1999/00 (HEO Thames Gateway ES, 2001).
Low water count data was available from counts carried out in specific areas, such as the counts in the vicinity of BP Refinery at Coryton (Shaw, 2005) and a series of counts were carried out as part of the London Gateway Environmental Statement. Information on bird usage of the study area has also been collated from other sources such as the Thames Estuary Partnership: Tidal Thames Habitat and Species Audit.