SEA-BIRD NUMBERS AND MAN IO5 



discharge of unwanted ofFal, and of unwanted species of fish, squids 

 and other molluscs. Every deep-sea trawler starts from port with a 

 retinue of gulls, some of which may follow for about fifty miles or more 

 to sea; a few occasionally farther. After that, in the deep ocean, ful- 

 mars are the principal scavengers in the wake of trawlers which work 

 the north-western and arctic fishing banks. Every time the haul 

 comes up in the coastal belt the gulls resting on the sea gather more 

 closely round the ship, and at every gutting time they scream and 

 fight for offal. The rise of the fishing industry has unquestionably 

 aflfected the population of the gulls round Britain, and a similar state 

 of affairs has been reported by A. O. Gross (1951) from the northern 

 United States sea-board. In 1900, for instance, the great blackback 

 was practically extinct as a breeding species in England and Wales. 

 In the years round 1930, however, Harrisson and Hurrell (1933) 

 estimated that between 600 and 800 pairs nested in Scilly, about 

 180 in Pembrokeshire, over 60 in Cornwall, 50 on Lundy, about 

 45 in the rest of Devon and about 60 in the rest of England and Wales. 

 These figures are probably trebled today; and a parallel increase 

 has taken place also in Ireland and west and north Scotland, where 

 the species has always had a large population. On the United States 

 sea-board before 191 6 the great blackback nested nowhere at all. 

 Its farthest breeding place was on the Canadian border of the Bay 

 of Fundy, but in 1906 a pair bred in Maine and in 1928 three pairs 

 certainly did so. By 1931 there were at least ten stations in Maine 

 and one in Massachusetts, and since then it has spread south as far 

 as New York. The U.S. population consisted of some 1,250 pairs in 

 1944. There are 700 pairs in one bay in Maine alone. 



But of all the birds which have been affected by man's dumping 

 of this kind of food into the sea the fulmar has responded most markedly. 

 Both of us independently came to the conclusion that the astonishing 

 spread of the fulmar — the biggest revolution in the numbers of any 

 widely-spread sea-bird (or any bird?) — is primarily connected with 

 modern trawling and probably with its predecessor, North Atlantic 

 whaling. This spread is described in detail in Fisher's The Fulmar 

 (1952), and we do not wish to recapitulate the evidence here. Suffice 

 it to say that the spread has been going on now for 200 years, having 

 been first started in south Iceland in the middle of the eighteenth- 

 century, that it has completely changed the bird's distribution in 

 Iceland, the Faeroes and Britain, and that it still continues, no less 

 than thirty colonies or potential colonies being founded annually 



