244 DISCOVERY REPORTS 



between 10 and 40 E lying to the south of South Africa, and one in the Bellingshausen 

 Sea, south of the west coast of South America. The existence of the first two groups is 

 further confirmed by Hansen's Atlas over Antarktis og Sydishavet (1936), which shows 

 on a series of maps the approximate positions in which whales of the three species were 

 taken in the seasons 1929-30, 1930-1, 1932-3, 1933-4 and !934"5- In the tw0 former 

 seasons some factories worked as far east as the Ross Sea and Balleny Islands, i.e. in 

 area V, Fig. 2, and it is quite evident from Hansen's atlas that they found there a fourth 

 concentration of Humpbacks, that is to say to the south of New Zealand and the east 

 coast of Australia. Whale marking by the 'William Scoresby' has not extended to this 

 region, but confirmation of a concentration here is to be found in the records of whales 

 seen during the voyages of the ' Discovery II '. Unfortunately, the number of Hump- 

 backs which could be identified with any confidence is very much smaller than the 

 number of Blue and Fin whales and quite inadequate for treatment on the lines of 

 Tables 11 and 12. However, out of about sixty identifications of Humpbacks spread 

 around the Southern Ocean, it happens that more than half were between 150 and 

 170 E, that is, in a region centred around the Balleny Islands. This is no indication 

 that there is really a bigger concentration here than in the other groups, but it is worth 

 mentioning as corroborative evidence of the existence of such a concentration. 



In former years very large numbers of Humpbacks were taken at South Georgia (see 

 Table 10, p. 235). The peak was reached in 1910-1 1 when over 6000 were killed. There- 

 after there was a heavy decline which is at least in part attributable to excessive hunting 

 (see Matthews, 1937, pp. 82-5). As was noted above, Fig. 3 suggests that there are still 

 traces of a group between 10 and 30 W, and this no doubt is the remnant of a formerly 

 important group which was presumably centred somewhere on the eastern side of the 

 Scotia Sea. It is not quite certain whether this group was distinct from that in 70-8o°W, 

 but since the latter is still so sharply defined in the whale-marking records of the 

 'William Scoresby' it is highly probable that there were in fact two distinct groups. 



The Antarctic Humpback stocks thus group themselves in the Bellingshausen Sea, 

 in the south-west Atlantic sector, to the south of South Africa, to the south-south-west 

 of Western Australia and to the south of New Zealand, one group falling neatly into 

 each of Hjort, Lie and Ruud's areas II-V. It is not merely a majority tendency, for 

 hardly any seem to occur in the gaps between. The positions of these groups would 

 alone suggest that they were related to the winter concentrations along the coasts of the 

 continents, and recoveries of whale marks have clearly shown that the groups centred 

 between 80 and ioo° E and between 10 and 40 E are in fact connected with the Hump- 

 backs found off West Australia and Madagascar respectively. Rayner (1940) shows that 

 thirty-six marks were recovered from Humpbacks, all of which were fired in Antarctic 

 waters and returned after intervals varying from a few days to 3! years. For full details 

 reference should be made to his report, but the essential facts are given in the condensed 

 data in Table 13. This shows that thirty recovered marks were fired in the group which 

 we now know to be concentrated about 80-100 E, and the one in 75 E doubtless be- 

 longs to the same group. Three were fired in the group south of South Africa, and the 



