27 g DISCOVERY REPORTS 



These solitary whales were known to the old whalemen as 'lone bulls'. When a solitary sperm 

 whale is encountered anywhere at sea, there are usually other solitary individuals in the same area. 

 Captain D. McKenzie (in Maury, 1852, p. 238) said that ' four or five may be as many miles from each 

 other'. I have a similar impression from what I have seen in the Azores and in the Antarctic, and 

 heard from whale-gunners. In the Antarctic I have never encountered solitary sperm whales which 

 were less than about one mile apart. Except for a single mention, made in general terms without 

 comment, of sperm whales schooling in the Antarctic (Mizue & Murata, 1951, p. 90), the experience 

 of scientists and whalemen is that individuals in high latitudes north and south appear to be always 

 solitary: these have been likened to rogue elephants, to the aged outcasts of herds. But Matthews 

 (1938, p. 158) has pointed out that the bulk of sperm whales from Antarctic catches are not yet 

 physically mature. It was natural enough in the past to suppose that lone bulls were aged, for these 

 whales, whether encountered in high latitudes or elsewhere, are comparatively large animals. But 

 lone bulls, although past sexual maturity* are by no means necessarily aged nor sexually effete, and 

 in this polygamous species a good proportion of them must simply represent those mature animals 

 which have temporarily failed to secure harem schools of females or which have not schooled with 

 other bachelors. 



Table 27. Sperm whales. Schooling. Monthly proportions in schools of whales caught at Fayal, Cais do 

 Pico, and Flores in 1948. The fractions are the actual ratios of that part of the catch recorded as seen in 

 schools to the total catch in each month. Percentages are given for males only, since it is seen that females 

 are invariably in schools 



Jan. Feb. Mar. Apr. May June July Aug. 



dutricT S3 ?? <?<? 99 6S 99 S3 1?? ZS 99 <?(? 99 <S<3 99 <?<? 99 



Proportions in schools 



T-i 4 3 5 3 20 13 5 1_ 



rayal — — * 4 — 73241381 



o-i 1 2 11 o_ 4 _«_ .2 3 s. 



Cais do a - — 3 T2 2 5 1023a 



Pico 



T^t 1 5 2 _§_ 3. 2J> 1_1 



r lores — f — — e 3 1032411 



rr* . 1 1 1 fl 14 5 11 3 3 2 3.0 3_0 12 



1 Otal "2 T 7" T8 8 IS 3 44 39 38 12 



S3 (%) (50) (100) 86 88 63 73 73 79 74 57 9° 



The males in schools may be mixed with a greater number of females, when the males of such 

 mixed schools are known as ' proprietor bulls ' or ' schoolmasters ' : the epitome of this association is 

 the harem school with one schoolmaster. Beale (1839, p. 51) says the harems have between one and 

 three schoolmasters. Other schools may consist solely of males, when they are called 'bachelor 

 schools '. The common porpoise also forms bachelor schools (Mohl-Hansen, 1954). Whales in bachelor 

 schools are not necessarily sexually mature although they may be (Schubert, 1951). A bachelor school 

 well known to the old whalemen is the band of young vigorous males, probably just sexually mature 

 but not yet large enough to secure harems, which used to be called the ' forty barrel bulls '. Bennett 

 (1840, p. 171) has noticed that older, larger whales can also form bachelor schools ; some of the winter 

 schools around the Azores may be such (pp. 279 and 284). The schools of females are nearly always, 

 perhaps always, accompanied by their proprietor bulls, although I have seen nursery schools at sea 

 where schoolmasters seemed to be absent, at least temporarily, from these bands of nursing whales 

 and calves. Just as there are nursery schools, it is evident from the run of the catches at Horta 

 that (as may be expected) there are schools consisting predominantly of pregnant whales. A kind of 

 mixed school not so far mentioned appears to be that of juvenile males and females, weaned but 



* Nishiwaki (1955, p. 148) estimated that 0-5% were sexually immature from a sample of 961 males caught in the 

 Antarctic. 



