200 WHALES 



be the fact that they suddenly find themselves in shallow waters. How it 

 is possible that this situation occvirs fairly freqviently, will be explained 

 in Chapter 8. On page i8i we have seen how sensitive porpoises are to 

 depth and Townsend, investigating Bottlenose Dolphins in the New York 

 Aquarium, found that the animals became extremely restless whenever 

 the water dropped below a certain level. Other contributory factors may 

 ■well be sudden temperature differences, or sudden thunderstorms. The 

 herd instinct is always very marked during such mass strandings. On 22nd 

 May, 1955, when seventeen young Killer Whales stranded on Parapara- 

 umu Beach (New Zealand), unsuccessful attempts were made to save 

 some of them by chasing them back into the sea. The animals would 

 always return and had finally to be abandoned to their fate. The same 

 behaviour has been repeatedly observed in Pilot Whales. 



Panic also seizes Californian Grey Whales whenever they are attacked 

 by Killer Whales. Sometimes they have the sense to retire into the 

 Californian bays, where the gigantic breakers form an insurmountable 

 obstacle for their enemies, but often they become so completely paralysed 

 with fear, that they simply float upside down, their white bellies and 

 extended flippers invitingly presented to the attackers. Degerbol and 

 Nielsen have described similar behaviour on the part of Belugas, which 

 also await the approaching killer as if petrified, though they do not turn 

 upside down. This attitude seems to be much more sensible, for it has 

 been noticed that, in this way, they often manage to escape the killer's 

 attention, possibly because the enemy cannot hear them. 



Panic is, however, not common to all Cetaceans, and certainly it is not 

 produced by every type of fear. The animals have, for instance, never 

 been known to become panic-stricken during big whale hunts, even when 

 entire schools are dispersed. During mass captures of dolphins, observers 

 have often been struck by the fact that large groups of these animals 

 allowed themselves to be slaughtered in turn without showing any signs 

 of unrest, let alone of real panic. 



No discussion of animal behaviour would be complete without some 

 mention of their sense organs, which, after all, are the animals' main 

 means of contact with the outside world. Animal behaviour is strongly 

 influenced by the nature of the sensory impressions the nervous system 

 receives. Groups of animals may, therefore, be said to inhabit different 

 worlds, human beings, apes and birds living predominantly in a visual 

 world, while dogs, horses, cattle and pigs live primarily in a world of 

 smells. Many of their surprising feats can thus be explained very simply. 



Little need be said about the Cetacean sense of smell, for the simple 

 reason that the olfactory organ is either absent or else so rudimentary 



