BRITISH MAMMALS 



parts about the Orkneys and Shetlands, and less frequently the English 

 and Irish shores. 



It has been known on several occasions to ascend rivers in England 

 for some considerable distance, even as far up as Chelsea on the Thames, 

 where three were seen in 1890. In character the Killer is fierce and 

 rapacious, and has been likened to the wolf of the seas. They usually 

 roam through the ocean in packs, travelling with great speed, and do 

 not hesitate to attack large animals such as the Greenland Whale and 

 Finner. Mr. E. W. Nelson, writing in the Rational Geographical 

 Magazine^ Washington, Nov. 1916, p. 468, says : " Unlike most whales, 

 the members of these schools do not travel in a straggling party, but 

 swim side by side, their movements as regularly timed as those of soldiers. 

 A regularly spaced row of advancing long black fins swiftly cutting the 

 undulating surface of the sea produces a singularly sinister effect. 



" The evil impression is well justified, since Killers are the most savage 

 and remorseless of whales." 



In attacking their quarry, if it be one of the larger Whales, the Killers 

 approach it on both sides, and generally endeavour to tear out the tongue 

 when the animal opens its mouth through exhaustion. 



Not only are whales and their young preyed upon by these fierce 

 marauders, but other warm-blooded creatures, such as Seals and the young 

 of the Walrus, also suffer. 



In the Northern Pacific great harm is done to the herds of the valuable 

 fur seal when Killers get among them during migration. " 



The Sperm Whale is safe from their attacks, as he is well able to defend 

 himself with his powerful jaws. 



Some authorities have considered that there are several species of the 

 genus Orca^ but whether this is correct is at present uncertain. 



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