PORPOISES AND DOLPHINS 297 



and Pacific coasts of North and South America, on the shores 

 of Tasmania, India, Africa and the British Isles, Psendorca 

 has been found, sometimes it is true in inconsiderable numbers, 

 but more often in strandings involving hundreds of animals. 

 The following records give some idea of numbers concerned : 

 " several hundreds " on Chatham Island in 1906 ; about 150 

 in the Dornoch Firth, Scotland, in 1927 ; over 100 near 

 Capetown in 1928 ; 167 on the Island of Velanai in 1933 ; 

 75 along the east coast of England and Scotland in 1935 ; 

 and in the same year and at very nearly the same time a 

 school of between 200 and 300 at Mamie, 50 miles from 

 Capetown. 



From its sporadic occurrence in inshore waters and its widely 

 distributed range it may be concluded that the False Killer is 

 a truly oceanic species, as distinct from a shore-frequenting 

 species. On the rare occasions when it invades shoal water it 

 comes into an environment outside the range of its normal 

 deep-water experience, for to such a creature the conditions 

 found in calm water over a shallow sand or mud flat or in 

 heavy seas breaking on a rocky coast must be quite novel. 

 The want of periodicity in the inshore migrations suggests that 

 it is some cause other than breeding which leads them towards 

 the coast. With reference to the most recent British stranding, 

 when seventy-five animals were found distributed along the 

 east coast from north of the Tay to the Wash, it was suggested 

 by the writer in ' The Scottish Naturalist ' that the phenomenon 

 was probably associated with feeding. Alteration in the usual 

 distribution of water masses in the ocean would cause alteration 

 in the distribution of the animals on which the False Killers 

 feed, and might bring them into areas where they are not 

 usually to be found. From 1930 to 1935 there had been an 

 increasing strength of flow of Atlantic water into the North 

 Sea, and it is possible that the Pseudorca invasion was linked 

 up, either directly or indirectly with that fact. 



The nature of the shore on which British specimens have 

 been found gives a clue to the immediate cause of stranding. 

 Where considerable numbers of animals have been involved 

 the shore in each instance extends into the sea as a wide flat 

 expanse of mud and sand, uncovered at low water, covered a 

 foot or two deep at high tide. At Donna Nook, Lincolnshire, 



