RORQUALS OR FIN WHALES 225 



animals found in the sea, but in the North Atlantic at any rate 

 its food varies more than that of its bigger relative. At one 

 period of the year it feeds on herring or one sort of krill, at 

 another on fishes called Capelin, and again on a smaller sort 

 of krill. In the Antarctic the Finner, like the Blue Whale, 

 feeds only on the one kind of krill already described, but it is 

 interesting to note that even when referring to this one species 

 of shrimp the whalers recognize Blue Whale krill and Fin 

 Whale krill, which are respectively its young and adult forms. 



At birth the Finner Whale is about 22 feet in length, and 

 grows with such speed that it is capable of reproducing at the 

 beginning of the third year of its life, when the males are 

 generally about 64 feet long and the females 66 feet. The 

 pairing season may extend over 7 to 8 months, but as regards 

 Antarctic Finners, May to August is the period of maximum 

 frequency. Mackintosh and Wheeler state that there is no 

 justification for the assumption that pairing can take place at 

 any time of the year. The period of gestation is about 360 days, 

 and the calves are suckled for the same length of time as in 

 the Blue Whale. Referring to the proportions in which males 

 and females are found, they say that it seems difficult to avoid 

 the conclusion that males are in a slight majority ; of all the 

 Fin Whales examined by them 45% were female and 55% 

 male. 



Data obtained from a vast number of whales led Wheeler 

 to conclude in a later work that cessation of the reproductive 

 function does not occur in whales up to 20 years of age, and 

 that there appears to be a sexual prime at 10 years. The 

 Finner is fully grown when 6 to 8 years old. 



This species 'is more gregarious in its habits than the Blue 

 Whale, which does not commonly gather in large schools, but 

 is more often seen singly or in pairs. Solitary Finners are 

 sometimes encountered, but more often they are congregated in 

 schools, which may range from a few individuals — a " stim " — to 

 two or three hundred in number. Millais, in ' Mammals of Great 

 Britain and Ireland ', reports that a whaling captain observed 

 nearly 200 Finbacks in sight at once from the masthead ; 

 they were scattered over an area of some 5 square miles, 

 singly or by twos and threes. Bennett says of them : " One 

 would readily believe that they (the Fin Whales) had a fixed 



