THE FOOD OF WHALES 



361 



FOOD 



The food of whales is principally the concern of the ships employed in the investi- 

 gations, for it is only by operations at sea that it can be effectively studied. A certain 

 amount of information, however, is to be had from the examination of the stomach 

 contents of the whales at the whaling stations. The species which constitute the whale's 

 food can be determined, and a rough idea can be formed of the fluctuations in abundance 

 and types of "krill" which occur on the whaling grounds. 



The whales caught at South Georgia (excluding the Sperm whale) feed exclusively 

 on Eiiphaiisia superba (Fig. 100) and have no other food whatever in their stomachs apart 

 from a few specimens of the Amphipod Euthemisto, which is so abundant in the plankton 

 round South Georgia that the whales can hardly help swallowing a certain quantity. 



Fig. 100. Outline sketch of Euphausia superba (:■: i| approx.). 



Off the South African coast the little food in the stomachs was found to include 

 Eiiphausia recurva, E. liicens and Nyctiphanes africamis, species which grow to a 

 length of less than i in. Doubtless all species of Euphausian occurring in the locality 

 are consumed without discrimination. One or two Humpbacks and one of the Fin 

 whales examined at Saldanha Bay had fish in their stomachs. Sperm whales were 

 feeding on cuttlefish, some of which appeared to have been of considerable size. 



The question of the migrations of whales has not yet been referred to, but it may 

 be mentioned here that there is a general movement northwards into warmer waters for 

 breeding during the southern winter and southwards for feeding during the southern 

 summer. Little food is available in the lower latitudes, but in certain parts of the 

 Antarctic and sub-Antarctic waters Euphausia superba flourishes in immense quantities. 

 It is to be found in dense shoals usually in the neighbourhood of land, and thus the 

 great feeding grounds of the southern whales are situated in such places as the vicinity 

 of South Georgia and the other Dependencies. The enormous abundance of the krill 

 round South Georgia is revealed by an examination of the stomach contents of the 

 whales caught there. Normally the stomach was found to be well filled with compara- 

 tively fresh Euphausiids and an empty stomach was at most times an uncommon 

 occurrence. Plate XXXV, fig. i, illustrates a typical case of the appearance of the 

 stomach after a slight opening in it had been made. 



The whales examined at Saldanha Bay showed a marked contrast. Here the stomach 

 was normally found to be empty or to contain a very small quantity of food and the 



K IV ^4 



