256 DISCOVERY REPORTS 



might be thought, like the abundance of cephalopod scars and oval scars, to give a clue to relative age, 



but it did not appear in 1949 to be correlated with the length of the whale. 



One male exhibited slight notching of the flipper, an injury I have also occasionally seen in sperm 

 whales and whalebone whales in the Antarctic. 



Whale F20, a male of 14-6 m., bore on the front of the head nine shallow dents, quite healed, and 

 each measuring about 5 cm. in diameter and 2 cm. in depth. I have seen three sperm whales in the 

 Antarctic with such wounds, some of them deeper and wider than those described here. Sperm whales 

 are generally believed not to see very well under water, and it seems likelv that the dents in the fore- 

 head are caused by accidental collision with a hard and broken sea bottom. During the cruise of the 

 Discovery II among the Azores in 1952, the ship operated an underwater television camera which 

 revealed, in the channel between Pico and San Jorge, a pinnacled bottom at 100 m. with rock faces 

 scoured of the cushion of sand or sediment, so it may be that in the Azores whales sometimes collide 

 with rocks on the rare occasions when they venture upon soundings, either when searching for food 

 (p. 261) or when chased inshore during a whale hunt. 



The occurrence of broken teeth in a few whales has already been noticed. 



FOOD 



Between 1949 and 1954 notes were made on the abundance of food in the first and second stomachs 

 of 294 sperm whales at Horta. In 1949 I also examined qualitatively the stomach contents of thirty- 

 nine whales, and in July 1955 examined a giant squid, Architeuthis sp., recovered from a stomach. 

 Most of the animals examined in 1949 had been dead for at least 18 to 19 hr., and, since digestion 

 continues after death, the food was usually decomposed to some extent. The first compartment of the 

 stomach has a non-digestive lining but even here some digestion takes place in the dead whale because 

 juices leak over from the second or true stomach. 



The staple food was squid, with large fish as a subsidiary, but not negligible, item of diet (Plate II, 



% 3)- 



Sqiad 



From each stomach examined in 1949 the squids were carefully pulled out, counted, and assigned by 

 eye to one of four arbitrary size-groupings. It was only occasionally that conditions on the flensing 

 platform allowed a specimen to be accurately measured. All lengths and size-groups in this series 

 refer to the standard length, that is, the distance from the tip of the body to the tip of the longest 

 wow-tentacular arm: the standard length is appreciably shorter than the total length which includes 

 the tentacles. Sometimes the head-and-arms of these squids were found separated from the bodies, 

 either severed at the ' neck ' when swallowed by the whale or digested away afterwards : the count in 

 such cases was made on the head-and-arms, for these could be more numerous than the bodies which, 

 lacking clinging members, may not always have been swallowed. There was no difficulty in assigning 

 trunkless squid to size-groups once a few complete specimens had been examined. 



The results of size grouping are shown in Table 1 1 . The lengths of the squids ranged from o-6 to 

 2-4 m. (2 to 8 ft.). One might suppose that male sperm whales, being larger than females, would take 

 rather larger squids, but actually males and females take food of much the same size : the average lengths 

 of squids eaten by males and females were 0-95 m. (3 ft. 2 in.) and 0-92 m. (3 ft.) respectively. For 

 squids from all whales the average size was 0-94 m. (3 ft. 1 in.). On board Fl. F. Southern Harvester in 

 the Antarctic season 1947-8 I made a similar analysis (unpublished) of the lengths of sixty squids from 

 the stomachs of male sperm whales. Here the diet was Moroteuthis ingens (Smith) and although the 

 length range was also 2 to 8 ft., the average length was 1-3 m. (4 ft. 3 in.). This comparison seems to 

 be a striking illustration of the greater size reached by marine animals in high latitudes. 





