T H E APPEARANCE in various parts of the British Isles every year, especially in March and April, of a few white-headed birds in flocks of Cormorants (Phalacrocorax carbo) has inevitably raised the question of the identification of the Southern race (Ph. c. sinensis) and whether it can be distinguished in the field, or at all, from our native bird (Ph. c. carbo). My own interest in the problem was first aroused on n t h March 1951 when two " w h i t e - h e a d s " were seen at Bassenthwaite, Cumberland, in a flock of 48 birds. Further observations were made of this and other flocks, until eventually all the wintering and breeding stations on both the Cumberland and the Scottish sides of the Solway Firth, as well as the F a m e Islands in Northumberland and haunts further afield, had been visited. In addition to many other detailed counts and comparisons a series of weekly observations, from 30th January to 27th March 1955, was made on a wintering flock near Silloth, Cumberland, to study the development of the spring plumage. In all, over 1,500 birds were examined. Records of observations made in other parts of the country have been sought and collected and have provided a valuable source of information. The British Museum (Natural History) and the local Carlisle Museum could not produce any skins of British white-heads. It was unlikely that any, or many, had been collected as there are
