Seaduck survey data
JNCC has carried out surveys of inshore waterbirds (seaduck,
divers and grebes) since the winter of 2000/01, primarily
using aerial surveys. These data are summarised in
aerial survey annual reports. The data are
further analysed as part of work progressing the identification of
inshore Special
Protection Areas (SPAs) for non-breeding aggregations of marine
waterbirds.
Some species or areas cannot
be adequately surveyed using aerial surveys. In particular, birds
that remain very close to the shore may be missed during aerial
surveys, as the aircraft makes sharp turns at the shoreline, and
grebe species are not easily detected during aerial surveys. It is
also sometimes difficult to identify divers to the taxonomic level
of species during aerial surveys, particularly in areas where
several species may be present. As a result, numbers of rarer
species such as black-throated diver may be under estimated in some
areas. Therefore, we use data from land-based or
boat-based surveys to supplement our aerial survey
data.