Forms large, spectacular colonies on rocky cliff faces. Pelagic in winter, sometimes within sight of land, particularly in bad weather or where there is plentiful food. ID: An attractive, dainty, clean and well-proportioned gull. Medium-gray upperparts. Short black legs and yellow bill. Buoyant but powerful flyer with long, slim body and wings. Wings often held straight, but sometimes elbow pushed forward creating ‘W’ along leading edge of wing. Stiff shallow wingbeats. Easy to overlook as RBGU, but slimmer, slightly darker with distinctive squared-off black wing-tip and different flight style. Ad br: white head. Nonbr: gray spot to rear of ear coverts. 2nd-year: as adult but some have more extensive black in wing. Juv/1st yr: bold ‘W’ pattern on upperparts. Some have dark ear spot and collar, others all white as adult. Black tail band. Black bill becomes yellow in spring/summer.