240 DISCOVERY REPORTS 



much importance, for it can be shown that the winter and summer groups are largely 

 one and the same. 



The existence of distinct groups of Humpbacks in the Antarctic can be established 

 by the movements of factories and statistics of catches, by the whale-marking records 

 of the ' William Scoresby ', and to some extent by the records of whales observed during 

 voyages of the ' Discovery II '. 



In their series of articles on ' Pelagic Whaling in the Antarctic ', Hjort, Lie and Ruud, 

 and latterly Bergersen, Lie and Ruud, divided the Antarctic whaling grounds south of 

 50 S into five main areas (see Fig. 2) as follows : 



I. A small area around the South Shetland Islands. 



II. 6o° W to o°, mainly the Weddell Sea and waters of the Falkland Islands 

 Dependencies. 



III. 0-70 E, from Bouvet Island to Kerguelen Island mainly to the south of South 

 Africa. 



IV. 70-1 3 o° E, from Kerguelen to West Australian longitudes. 



V. 130 E to 170 W, south of New Zealand and including the Ross Sea. 



Area I was defined merely to provide for the restricted operations of factory ships 

 moored in harbours of the South Shetlands and is now of little importance. The limits 

 of the other four areas were based on the distribution of the whaling fleet, and these 

 authors showed that the factory ships always form a separate concentration in each area, 

 except that area V has not been worked in recent years. Since the factories naturally go 

 where they expect to find plenty of whales, it is inferred that the whales tend to form 

 separate concentrations in each of the four areas. This will be referred to in more detail 

 in connexion with the distribution of Blue and Fin whales, which are of course the 

 species which influence the movements of the whaling fleet. In the meantime some more 

 precise evidence on the distribution of Humpbacks is to be found in some catch 

 statistics given in the same series of publications. The whaling grounds are further sub- 

 divided into squares measuring io° of latitude and longitude, and tables are given show- 

 ing the number of whales of each species caught in each month in each square. In the 

 earlier articles the distribution of only Blue and Fin whales is given, but articles VII 

 (table I, pp. 31-4) and VIII (table I, pp. 30-3) give separate figures for Blue, Fin, 

 Humpback, and 'other' whales. These two latter articles deal with the seasons 1936-7 

 and 1937-8, when large numbers of Humpbacks were taken. 1 Table 1 1 here is a further 

 analysis of those published in articles VII and VIII. For each io° of longitude I have 

 added together all the whales taken south of 50 S (i.e. making no distinction between 

 those in 50-60 and those in 60-70 S). All three species are included because it is 

 necessary to show that large catches of Humpbacks in any particular region are not 

 simply due to scarcity of the other species. ' Factories' days ' means the total number of 

 effective working days spent by the factories in the region in question. In Hjort, Lie and 



1 The catching of Humpbacks by factory ships in the Antarctic was prohibited by International Agree- 

 ment in 1938. 



