The surveys were carried out in the months of December 2002 and March 2003, as part of the JNCC annual programme of surveillance of wintering inshore waterbirds in the UK.  The aim of the surveys was to collect data on the wintering numbers and distribution of inshore waterbirds in areas of the UK known to be important for these groups of species.

 

The shortage of suitable aircraft and weather conditions during the winter prevented the undertaking of repeat surveys of most of the programme's core areas covered during previous winters.  In addition, poor weather conditions and/or exclusion from military airspace prevented the completion of the majority of surveys undertaken.

 

The areas covered by surveys in 2002/03 were Scapa Flow, Stronsay Firth, the Dornoch and Inverness Firths, parts of the Moray Firth, and the west coast of the Outer Hebrides.  Surveys were conducted from a light aircraft, following a line-transect method to collect data that was suitable for both distance sampling – to estimate total numbers of birds, and geostatistical modelling – to identify areas with the highest densities of birds.

 

Seven species of inshore waterbirds were recorded comprising red-throated diver (Gavia stellata), great northern diver (Gavia immer), common eider (Somateria mollissima), long-tailed duck (Clangula hyemalis), black scoter (Melanitta nigra), common goldeneye (Bucephala clangula) and red-breasted merganser (Mergus serrator).  In addition, birds were recorded that could be identified only as diver species, grebe species, or scoter species.

 

Within the areas surveyed, several sub-areas were particularly important for inshore waterbird species; the area around Hoy, Fara and Flotta in Scapa Flow; the Sounds of Harris, Monach and Barra in the Outer Hebrides; the southern half of the Dornoch Firth; and the Inverness and inner Moray Firths.

 

This report describes the methods used during aerial surveys of wintering seaduck, divers and grebes during the winter of 2002/03 and presents the recorded numbers and daytime distributions of those species recorded in each survey area.