A STUDY OF COLONIES OF THE KITTIWAKE RISSA TRIDACTYLA (L.)

Summary. The history of Kittiwake colonics at Marsden, Co. Durham and North Shields, Northumberland is given. Since the original colonization of the area in 1930, nine colonies have been formed which, in 1954, ranged in size from 13 to 648 nests. New colonies were formed by birds being present on the site a year before breeding commenced. Immigration continued for at least the first four years of a colony's existence. Colour‐ringing showed that...