BEHAVIOUR 199 



grown to well over one hundred, in one of which six ribs and five vertebral 

 processes had broken and then healed. That the original injuries were not 

 man-inflicted appears clearly from the fact that they are as frequent in 

 fossil whales and Cetaceans not pursued by man as in those which are 

 hunted by him. As mere bites could not have inflicted such serious 

 fractures, they must be the result of violent strokes of the tail, and since 

 Cetaceans have no enemies apart from Killer Whales, which attack their 

 victims with their teeth and generally kill them in the process, the healed 

 fractures can only have been caused by congeners. 



If such scars and fractures were restricted to male animals, one might 

 have thought of fights arising out of sexual rivalry, but social rivalry seems 

 the better explanation, the more so since violent fights over cows have 

 only been reported of Sperm Whales. The evidence also points to the fact 

 that violent fights over food do not occur, so that the social hypothesis 

 seems to fit all the known facts best. Still, it remains an hypothesis, and 

 every observation which increases our knowledge in this field will earn the 

 gratitude of all marine biologists. 



All herds are sometimes seized by sudden panic. Thus, cattle will race 

 blindly over the plains, drowning in rivers or falling down gorges on the 

 way. The mass strandings of scores and even of hundreds of Cetaceans are 

 said to be caused in the same way. Such strandings have been observed 

 mainly in the case of Killer Whales, False Killers and Pilot Whales, and 

 seem to occur quite frequently. In 1927, 150 False Killers were found 

 stranded in the Dornoch Firth (Scotland), and in 1929, 167 False Killers 

 ran aground at Velenai (Ceylon). Further recorded mass strandings of 

 False Killers occurred at Zanzibar (1933-54 animals); in the Darling- 

 District of South Africa (1935-200 animals); on St Helena (1936-58 

 animals) ; and on the coast of Britain (1936 - 75 animals). On 14th March, 

 1955, 67 Pilot Whales stranded at Westi'ay (Orkneys), and de Kok (1959) 

 reports that the strandings were preceded by a panic during \vhich the 

 animals ^v'ounded one another by their uncontrolled movements. 



Though Killers may possibly be stranded while pursuing seals or sea- 

 lions into shallow waters, the two other species, which feed mainly on slow- 

 swimming cuttlefish, cannot possibly run aground for the same reasons, 

 nor can Sperm Whales of which mass strandings are also reported. On 

 14th IVIarch, 1784, thirty-two of these giants were stranded at Audierne 

 (South Brittany), and on 27th February, 1954, the Associated Press 

 reported that thirty-four Sperm Whales had been found stranded at La 

 Paz (Gulf of California), whose inhabitants were assailed by the unwhole- 

 some stench of decomposing carcasses for a long period, since twenty-four 

 Sperm Whales had run aground here two weeks earlier. 



One of the reasons why these animals become panic-stricken may well 



