2 i2 DISCOVERY REPORTS 



analysis of these observations. It does not include those in which blood was seen to be 

 present, for that might mean that the stomach had been damaged by the harpoon with 

 consequent loss of the contents. It is clear that the whales taken at Durban had scarcely 

 been feeding at all. 



Table 7. Amount of food found in the stomach of whales 

 examined at Durban, 1930 



In certain temperate coastal regions some of the whalebone whales find an extra 

 article of diet in the ' lobster krill ' which is the pelagic post-larval (or Grimothea) stage 

 of the crustacean, Munida gregaria. Descriptions of this organism and its habits are 

 given by Matthews (1932) and Rayner (1935). Swarms of Grimothea occur locally in 

 great abundance in the neighbourhood of the Falkland Islands, Patagonia and Tierra 

 del Fuego, and around the coasts of New Zealand. It is not found anywhere in Ant- 

 arctic waters, and does not appear to have been recorded from such places as Kerguelen 

 or so far north as South Africa, so that it must play a minor part in the nutrition of the 

 southern stocks of whales as a whole. Sei, Humpback and Right whales taken off the 

 Falkland Islands are recorded as feeding on it, and it is evidently of some importance to 

 Humpbacks passing through the coastal waters of New Zealand in winter. Ommanney 

 (1933, p. 249) notes that the south-bound Humpbacks here have a certain amount of 

 food in their stomachs, some of which has been identified by Matthews as lobster krill, 

 though the north-bound whales generally have empty stomachs. It is not clear whether 

 it is ever eaten by Blue and Fin whales. The swarming of Grimothea may take place 

 throughout the year though it is most commonly recorded in the summer months, and 

 it may be that it forms a major part of the diet of Sei whales, which seldom come so far 

 south as the zone inhabited by Euphausia superba except at the warmest time of year. 



The principal purpose of these notes is to show that the majority of southern whale- 

 bone whales feed heavily in the Antarctic in summer and find little to eat in warmer 

 waters in winter. The fact that whales arriving on the southern whaling grounds early 

 in the Antarctic summer are known to have thinner blubber than at the end of the 

 season (see p. 250) itself suggests that they have had comparatively little to eat during the 

 winter. On the whole we are justified in concluding that during the summer in the 

 Antarctic, Blue, Fin and Humpback whales consume large quantities of krill, and that in 

 warmer regions in winter they manage to a large extent without food except for a very 

 meagre diet of certain small Euphausiidae, some lobster krill here and there, and per- 

 haps an occasional meal of fish. There is perhaps some doubt as to the extent to which 

 Humpbacks can feed on fish during the winter, but it is not likely that they find feeding 



