SEA-BIRD NUMBERS AND MAN 57 



P.A.D. Hollom (1940) had no colony known (or not known) to be 

 occupied in 1938 to add or subtract from his Hst of 342 such colonies. 

 When Fisher and Vevers (1943-44) organised a census of the North 

 Atlantic gannet in 1939, only two small colonies of the twenty-three 

 which then existed were overlooked in that year. When Fisher and 

 Waterston (1941) reported on the fulmar colonies known to them in 

 Britain in 1939 they believed that there were 208 separate stations 

 at which the fulmars were breeding. Ten years later, after carrying 

 on research and correspondence with the same intensity to discover 

 the situation in 1944 and 1949 (during which 'back information' 

 was also collected), Fisher discovered that he had overlooked only 

 nineteen, all small (and some in very remote parts), and unimportant 

 as far as the fulmar's population, or the actual extent of its range, were 

 concerned. 



A census of the sea-birds of the North Atlantic is no longer a wild 

 dream. A start has been made with certain obvious species, with 

 limited distribution or small populations. The organisational prob- 

 lems are not insuperable; we have an ever-increasing body of highly 

 competent bird-watchers available for, and keen on, the counting 

 of nests: for a sea-bird census depends on the assessment of the number 

 of occupied nests. Such a census has already been performed for 

 several species on the coasts of Germany (Schulz, 1947), and, judging 

 from the descriptions of the distribution of sea-birds in Sweden (Lunde- 

 vall, unpublished), Denmark (Jespersen, 1946, and Loppenthin, 

 1946), the Netherlands (van Ijzendoorn, 1950) and Belgium (Ver- 

 heyen, 1951), it need not be long before a census of the southern North 

 Sea and Baltic could be complete. In Britain good surveys, if not 

 censuses, exist for the sea-bird colonies of most counties in England, 

 and there are records published in the present century concerning 

 almost every bird-cliff in mainland Britain (though not every species 

 on the cliff) and many in the Hebrides, Northern Isles and Ireland. 

 Complete censuses, or careful estimates, have been made of many 

 species of sea-birds in various countries with a North Atlantic-Arctic 

 seaboard; of which a selection is: 



Some Censuses 



of apparently occupied nests (i.e. an approximation to the 

 apparent total hv tiding pairs) of North Atlantic sea-birds in some 

 parts of their range (in a few cases, world census) . Censuses of 



