124 DISCOVERY REPORTS 



This reaction suggests a change of mind and it has usually happened well in advance of the need to 

 break surface; but sometimes it has happened when emergence was inevitable, as two or three times 

 when the caudal peduncle, and once the neck region, was thrust out of the water in the act of diving 

 (31 January and 7 February, sec p. 128). 



Feeding 

 On 1 1 January, whales in the act of feeding came under direct observation. A heavy concentration 

 estimated to number 100 200 whales was centred over a patch of whale food in an area of about 

 4-5 square miles. 



The krill {Euphausia superba) could be seen in a layer no more than 3 m. below the surface, and in 

 places it affected the colour of the sea. An easterly gale the previous day had left a very heavy swell, 

 but the wind had since moderated and waves were no longer breaking. The sky was grey and the bad 

 visibility was reduced from time to time by patches of mist. The sea was grey too, but in places the krill 

 imparted to it a barely noticeable tinge of ochre. In one place where the krill was unusually thick and 

 might have been closer to the surface, a patch of half an acre or so had a brick-red tinge. The krill was 

 irregularly spread over the whole region with large gaps between the swarms ; some measured a few 

 feet across and had an indefinite contour like that of a gorse bush, and others extended in long wavy 

 bands from one to several feet or even metres in width. The krill did not seem as dense as patches of 

 it often are, and it looked as though it had been broken up by the recent gale and had been depleted 

 by the depradations of the whales. 



The whales were banded together in small schools of from two to five or six or more ; but the schools 

 were probably mixing. The animals were blowing leisurely, and sounding for short periods. In the 

 early part of the day and late in the afternoon they showed a disposition to run away from the ship ; 

 but in the middle of the morning, when they seemed to be feeding most actively, they took little heed 

 of us and marking was comparatively easy. 



The most conspicuous feature of their feeding was the tendency to swim on one side.^ From afar, 

 the white ventral surface shone beneath the water so that its blueness was momentarily thrown up. 

 There would appear to be no need to look for any other explanation of this than that it is a method of 

 turning sharply to one side (see p. 131). Whales sometimes turned out of a normal act of blowing on 

 to their side before submerging and sometimes turned while under water; if close to the surface, 

 flipper or fluke broke surface and waved in the air. 



A point to be emphasized was the supreme indifference with which the whales accepted the marking 

 and the presence of the marking vessel when actively feeding. They blew leisurely, sometimes swimmmg 

 towards us, beneath us and by our side, and they seemed to be preoccupied with the question of 

 their meal. 



The salient facts in these observations, for purposes of future comparison, are as follows: 



(i) The whales were feeding, 

 (ii) They were close to the surface, 

 (iii) They were concentrated together, 

 (iv) The schools were of varying size, 

 (v) They were blowing leisurely and at short intervals, 

 (vi) Their unconcern for the ship gave an appearance of preoccupation. 

 A rather similar state of things was observed north-west of the South Sandwich Islands on 

 22 January. During the morning the ship had been pursuing whales, but marking with only partial 

 success, for the schools were unapproachable and one after another had led the ship a run of 30-40 

 1 I am informed by Mr G. W. Rayncr that Norwegian whalers have the word 'boltering' to describe this habit. 



