SOUTH 
numbers of the humpback is very noticeable, and even allowing for 
the possible increase in size of : ear for the captm-e of the larger and 
more lucrative blue and fin whales, there is sufficient evidence to 
warrant the fears that the humpback stock is threatened with ex- 
tinction. 
In the immediate northern areas — in the region from latitude 
50*^ S. northward to the equator, which is regarded as next in im- 
portance quantitatively to the^^ sub-.Vntarctic, though nothing hke 
being so productive, the captures are useful for a comparative study 
in distribution. At Saldanha Bay, Cape Colony, in 1912, 131 whales 
were captured and the percentages were as follows : 35 per cent, 
humpback, 13 per cent, fin whale, 4 per cent, blue whale, 46 per cent, 
sei-whale ; while nearer the equator, at Port Alexander, the total 
capture was 322 whales, and the percentages gave 98 per cent, 
humpback, and only 2 captures each of tin and sei whales. In 
1914, at South Africa (chiefly Saldanha Bay and Dm^ban), out of 
a total of 839 whales 60 per cent, were humpback, 25 per cent, 
fin whales, and 13 per cent, blue whales. In 1916, out of a total of 
853 whales 10 per cent, were humpback, 13 per cent, fin whales, 
6 per cent, blue whales, 68 per cent, sperm-whales, and 1 per cent, 
sei-whales. In Chihan waters, in 1916, a total of 327 whales 
gave 31 per cent, humpbacks, 24 per cent, fin whales, ^ 26 per 
cent, blue whales,^ 12 per cent, sperm-whales, and 5 right whales. 
There seems then to be a definite interrelation between the two 
areas. The same species of wiiales are captured, and the periods 
of capture alternate with perfect regularity, the fishing season oc- 
curring from the end of November to April in the sub-Antarctic 
and from May to November in the sub-tropics. A few of the com- 
panies, however, carry on operations to a limited extent at South 
Georgia and at the Falkland Islands dming the southern winter, 
but the fishing is by no means a profitable undertaking, though 
proving the presence of whales in this area during the winter 
months. 
The migrations of whales are influenced by two causes : 
(1) The distribution of their food-supply ; 
(2) The position of their breeding-grounds. 
In the Antarctic, dming the summer months, there is present in the 
sea an abundance of plant and animal life, and whales which feed on 
the small plankto7i organisms are correspondingly numerous, but 
in winter this state of things is reversed, and whales are poorly 
represented or absent, at least in the higher latitudes. During the 
drift of the Endurame samples of plankton were taken almost daily 
360 
