OCEANIC MAMMALS 493 



general movement of the schools towards the equator during 

 winter" (Matthews, 1938a). The species is polygamous, with 

 many more adult females than males in the mating herds. The 

 main pairing season is from August to December, with its peak 

 in October. The period of gestation is about 16 months, and 

 the young one when born is about 4 meters long. 



The food of the sperm whale is largely squids, especially of 

 the smaller species, but the males may devour larger species 

 and are said even to attack and eat the giant squids. Some- 

 times the marks of the large sucking disks of the squids and the 

 scratches from their claws may be seen on the skin. Fish, too, 

 are sometimes found in their stomachs, and Dr. R. C. Murphy 

 has even recorded the presence of a seal's mustachial bristle in 

 the ambergris recovered from a sperm whale. 



While found in all the oceans, there were nevertheless 

 favored regions, or "grounds," well known to the whalers of a 

 former period, where these whales congregated, doubtless 

 drawn by abundant food. In a recent account, Dr. Charles H. 

 Townsend (1935) has plotted the localities where, in old log- 

 books, sperm whales were recorded as killed. The records show 

 that among these "grounds" those off Charleston, S. C., off the 

 Azores, off Brazil, in the western Indian Ocean, east of Japan, 

 and about the Hawaiian Islands and off Peru were famous 

 resorts for sperm whales. The beginning of the decline of this 

 species in the last century came about 1837, or 20 years or 

 more prior to the use of kerosene ; hence it is believed that the 

 persistent hunting of the previous hundred or more years had 

 by then seriously depleted the numbers. The substitution of 

 kerosene and later of electricity for lighting purposes undoubt- 

 edly saved the species from very serious diminution, yet it was 

 not for a number of years after the introduction of the new 

 illuminants that the numbers recuperated to a visible extent. 



The present situation is summed up by L. H. Matthews 

 (1938a) as follows: The sperm whale is taken in numbers at the 

 present time mainly on the Natal, Chile, and Japan "grounds," 

 whereas elsewhere the whalebone whales are those chiefly 

 sought. Yet the total catch for 1934-35 was 2,238, a rather 

 large number, although as Matthews points out, less than the 

 annual catch in the days of American whaling of the last 

 century. Sperm-whale oil and spermaceti are no longer 

 handled separately in utilizing this whale; furthermore sperm 



