THE HUMPBACK WHALE 85 



the outlook for the continued presence of large schools of Humpbacks in those regions 

 very uncertain. 



The only chance for the Humpback whale to regain its numbers is for the capture of 

 it to cease everywhere for a number of years, and thereafter for its pursuit to be re- 

 stricted to a limited number on the southern whaling grounds only.^ 



SUMMARY 



This report discusses the results of the examination of sixty-two Humpback whales 

 at the southern whaling stations during the course of the Discovery investigations. 



The extensive statistics in the British Museum relating to whaling are also used in 

 conjunction with the data collected by the Discovery staff. 



The sex ratio of the Humpback appears to be nearly even, ahhough some degree of 

 segregation of sexes may occur in certain places or at certain times. 



A series of standard measurements was carried out on the whales and the resulting 

 figures are discussed. The body proportions of the southern Humpback whales are 

 established, and their range of variation is recorded. As far as comparative evidence is 

 available there is no indication of structural difference between the Humpback whales 

 of the northern and southern hemispheres. 



The colour pattern of the species can be divided into groups. Whales of all colour 

 groups occur everywhere, but there are considerable indications of the predominance 

 of one or more colour groups in particular localities. 



Hair appears on several parts of the head, the hairs being placed mostly on tubercles, 

 and varying from eighteen to thirty-four in number on the snout. 



The ventral grooves are fewer in number than in the whales of the genus Balaenoptera, 

 and vary from twenty-one to thirty-six. They appear to be in all respects similar to those 

 of northern Humpbacks. 



The baleen is coarse, and grey to black in colour. A number of white plates com- 

 monly occur at the anterior end of the series and are frequently associated with an 

 adjacent white splash on the darkly pigmented snout. On plotting the baleen length 

 against total length of whale a sharp rise in the rate of growth is found between the body 

 lengths of 7 and 8 m., at which size the calf is weaned. 



The external characters of southern Humpbacks, like the body proportions, do not 

 appear to differ materially from those of northern examples of the species. 



The food of Humpbacks at South Georgia is exclusively krill, Euphausia superba, but 

 off the coast of Africa it commonly consists of small fishes. Nearly all whales at South 

 Georgia are feeding, but off South Africa very few of them are. 



The blubber of the Humpback is comparatively thicker than that of other species. 

 The blubber of immature whales is not only relatively but absolutely thicker than it is 



1 Since this report was written the International Whaling Conference has reached an agreement, which, 

 if ratified by the various governments concerned, will give the Humpback whale much more protection 

 than it has previously enjoyed. 



