Assessing behaviour of Lesser Black-backed Gulls from the Ribble and Alt Estuaries SPA using GPS tracking devices

This report provides findings from the first year of a study that has used Movetech ‘GPS-GSM’ tracking devices to track the movements of Lesser Black-backed Gulls from a breeding colony at the Ribble and Alt Estuaries SPA and so investigate their use of the SPA and the Warton Aerodrome. The study had two main objectives: (i) to assess the flight altitudes of adult Lesser Black-backed Gulls from the breeding colony at Banks Marsh in the Ribble and Alt Estuaries SPA during the 2016 breeding season; and (ii) to assess the home ranges of adult Lesser Black-backed Gulls from this colony and their temporal and spatial overlap with the SPA and the area of potential risk of collision with aircraft.