This review is a systematic assessment of the coverage of important aggregations of breeding and non-breeding birds by England’s network of Sites of Special Scientific Interest (SSSI). The main ornithological features of special scientific interest relevant to this report are nationally important aggregations of breeding or non-breeding birds, smaller isolated colonies of particular species (eg, Grey Herons) and assemblages of breeding birds.
Data from a wide range of sources have been reviewed to identify and list important aggregations for each species. Key data sources include the Wetland Bird Survey (WeBS), the Seabird Colony Register and the recent national Seabird 2000 census, Rare Breeding Bird Panel reports and single species national surveys (eg, Nightjar 2004 and Woodlark 2006).
A list of important locations for birds generated by the review of these data sources has been matched against the location of existing SSSIs to indicate the level of coverage. A database of ornithological interest features for all SSSIs was then used to check the status of important bird aggregations occurring within SSSIs.