8o 



DISCOVERY REPORTS 



companies at South Georgia continued whaling during the winter, and in most winter 

 seasons up to that date a considerable number of Humpback whales was taken. Speaking 

 of the northern Humpbacks Ingebrigtsen (1929) says, "It is mainly the adult animals 

 of both sexes that take part in the great breeding and food migrations, while the younger 

 animals are more erratic in their migrations." When the Humpback occurred in South 

 Georgian waters in large numbers, in the days of the great Humpback fishery there, 

 according to Hinton (1925), it used to appear off the island first in October; the largest 

 herds used to arrive in November and remain during December and January ; and by the 

 middle of May they were all gone. The latter remark needs qualifying, for, as shown 

 above, a fair number of Humpbacks was at one time taken during the winter at South 

 Georgia. 



If we now compare Figs. 79 and Figs. 55 and 56 it is evident that the peak in Fig. 56 

 falls between the peaks in Fig. 79, showing that parturition occurs at the northern limit 

 of the migration in the month of August and pairing takes place during the first part of 

 the migration to the south. Olsen (1914-15) states that the virgin females go north for 

 pairing, and that it is rare to see pairing taking place off the coast of South Africa, though 

 the graph in Fig. 1^5 shows that it undoubtedly occurs. 



Figs. 81 and 82, in which the length frequencies of both sexes of Humpback whales 

 are plotted for several seasons at South Georgia and South Africa, show that the com- 



S.Georgia. 1925-Gto 1930-1 



— ---Cape Province. I3?0- 5 



Fig. 81. Humpback whale. Males. Length fre- 

 quencies in the catches at South Georgia and 

 South Africa. 



B 10 12 14 



"fbtal Length in metre5 



5 Africa: Natal 1925.1930 



SaldanhaBaL|.l9ZB 

 5. Georgia 1925-5 to 1930-1 



Cape Province 1920-5 



Fig. 82. Humpback whale. Females. Length fre- 

 quencies in the catches at South Georgia and 

 South Africa. 



position of the whale populations is very different in the two places. The graphs are 

 bimodal for females in both places, and for males in Natal, but unimodal for males at 

 South Georgia and Cape Province. In the bimodal curves the first peaks represent 



