THE STOCK OF WHALES 453 



The small proportion of the total stock which appears to exceed six years is significant, 

 for it suggests that the maximum age which a whale attains is a good deal lower than 

 might have been anticipated. 



THE STOCK OF WHALES 



THE CONSTITUTION OF WHALE POPULATIONS 



In the preceding sections the external characters, nourishment, reproduction and 

 growth of the southern Blue and Fin whales have been separately dealt with and it 

 remains now to consider the whole subject from a more general point of view. To 

 begin with, in order to imderstand the effect which hunting is likely to have on the 

 stock of whales, one needs to know, among other things, the composition of the com- 

 munities or populations of whales which have become the object of the whalers' 

 activities in difterent localities, and the fluctuations which take place in their occurrence 

 and distribution. This involves an examination of the relative abundance of the species 

 of whales; the proportions of males and females, of immature and adult whales, of 

 pregnant, nursing and resting females; and a study of the fluctuations of these classes 

 of whales and the degree to which they are mixed or segregated. 



It need hardly be pointed out that whales are not scattered evenly throughout the 

 southern ocean but are more or less concentrated in certain areas, although at the same 

 time they are generally on the move. This implies that they tend to move in close aggrega- 

 tions through some comparatively limited regions and in a more dispersed form through 

 other less limited areas, or that they travel perhaps in herds which spend part of their 

 time in recurring visits to the same regions and part in travelling over various routes 

 in the open ocean. For example, there must be great numbers of whales which regularly 

 visit the coastal waters of South Georgia and other parts of the Dependencies where 

 supplies of food are concentrated, and spend much of the rest of their time in migrations 

 which take them far from land. It would appear in fact that the limitation of the areas 

 in which Euphaiisia siiperba lives in such abundance is mainly responsible for the 

 concentration of the whales in those areas, and therefore renders the catching of whales 

 in large quantities comparatively easy. The vast majority of whales caught, for instance, 

 oft' South Georgia are found within about forty miles of the coast, and if they happen 

 at any time to become scarce within this range the whalers do not usually expect to 

 find more by going much further from land. 



The whaling industry does not, of course, need to rely on the great feeding grounds 

 for its catches. Off the African coasts a moderate number of whales are caught, but 

 here each station uses a comparatively large number of boats and the climatic conditions 

 are much more favourable. The actual number of accessible whales is not to be compared 

 with that at South Georgia or the South Shetlands. 



The best known and most extensively exploited feeding grounds and areas of 

 concentration are South Georgia and the South Shetlands. There are, of course, other 

 such places as, for instance, in the Ross Sea where whales are known to exist in great 



