238 DISCOVERY REPORTS 



towards the equator ; hence the comparative scarcity of this species in the Saldanha Bay 

 catches and their plentiful occurrence farther north at such centres as Angola and the 

 Congo (see Table 9, p. 229). On this coast some of them pass north of the equator so 

 that an interchange of stock between the southern and northern hemispheres seems by 

 no means impossible. Regular northward and southward movements in winter are 

 known off the coasts of Australia, New Zealand and South America, and in summer, 

 when they have left these regions, they appear in comparable numbers in the Antarctic 

 catches. On these facts alone there could hardly be any doubt of the existence of a 

 seasonal migration between the Antarctic and the tropics, and the results of the Dis- 

 covery Committee's programme of whale marking puts the matter beyond dispute. 

 Rayner (1940) shows that a considerable number of marks fired into Humpbacks in the 

 summer season on the Antarctic pelagic whaling grounds between 80 and uo° E have 

 been recovered in winter off the West Australian coasts in about 24 S after intervals of 

 I, 1 \, z\, etc., years. Others have been recovered in the following or subsequent 

 summers near the place where they were marked. Marks fired in another part of the 

 Antarctic have been recovered from the coast of Madagascar. 



It is known also that pairing and parturition take place in winter when the Humpbacks 

 are in tropical or temperate waters, and it has been shown (pp. 209-13) that those taken 

 in the Antarctic in summer are nearly always feeding heavily, while those taken in warmer 

 regions in winter eat little or nothing unless they can now and then find a meal of fish. 

 There is no doubt then that Humpbacks undertake regular migrations to the Antarctic 

 in summer where they find plenty of food, and to the coastal waters of the southern 

 continents in winter where breeding takes place but where food must be relatively 

 scarce. It is to be supposed that the vast majority of the Humpbacks take part in the 

 migration, but as Matthews has pointed out, some remain in high latitudes over the 

 winter, for they have been taken at South Georgia, when winter whaling was carried on 

 there to some extent up to 1917-18, and it is possible that some, especially the immature 

 whales, remain in the warmer latitudes over the summer. 



The winter concentration along the continental coasts suggests that comparatively 

 few Humpbacks, and possibly none at all, wander about the open spaces of the Atlantic, 

 Indian and Pacific Oceans during their northward migrations. It also implies a division 

 of the Humpback stocks, at least in winter, into certain major groups. It has been shown 

 above that the species occurs, or has occurred, in sufficient numbers to support, or at 

 least contribute to, local whaling industries off (a) the west coast of South America, 

 {b) the coast of Brazil, (c) the west coast of Africa, (d) the east coast of Africa and 

 Madagascar, (e) the west coast of Australia, and (/) New Zealand and the east coast of 

 Australia. (Statistics of the catches in all except the last of these places are given in 

 Table 10, p. 234, and accounts of the fisheries at the last are given by Ommanney (1933) 

 and Dakin (1934).) In short, this species resorts to both sides of each of the three 

 southern continents. 



These features of the winter grouping are of course well known, but it is not so well 

 known that there is also a grouping of Humpbacks in the Antarctic in summer. This is of 



