These can be used to output a ten figure (10 meter) National Grid reference for the zone centroid.
The search can be carried out by street, postcode, place or Ordnance Survey grid reference.
Inland colonies of gulls, terns and great cormorants were defined by a single six figure grid reference denoting the center of the colony.
In order to map the spread of Argiope in the Newsletter I need a minimum of ten km grid reference and year date data.
During most of the SCR census, the position of each distinct group of pre-breeding birds was recorded with a single OS grid reference.
