118 



ALASKA FISHERIES AND PUR INDUSTRIES IN 1917. 



more accurately guessed than an unloiown weight locked up inside 

 of a container. But the length of the live animal can be estimated 

 under any circumstances within 2 or 3 inches. This was demon- 

 strated to the 1914 investigation committee by the writer, and a 

 method of measuring was worked out which has steadily grown in 

 popularity. The superiority of the method as a means of deter- 

 mining the size of skms being obtained over a guess at the age or the 

 weight of the skins has been conclusively proved in three years' 

 experience. By correlating the lengths with the ages of known 

 branded animals an age relation to length has been estal)lished, 

 and when the length of an animal is known it is also known whether 

 it falls within the limits of length of the average seal of one age or 

 the other. 



A comprehensive study of the growth of fur seals is in preparation, 

 but must necessarily proceed for several more years before being 

 finished. The following standards, however, have been adopted 

 from the studies already made as representing the lengths of average 

 animals of each age thus far studied. It should be added that the 

 limits are subject to change, as more data on growth of the animals 

 are accumulated. 



T. ese standards have been used in segregating the classes of the 

 several a^es of seals killed during the year ended August 10, 1917. 

 The yearlings are somewhat indefinite because only three unques- 

 tionable animals of this age have ever been studied; and these were 

 in the fall. They do not reach the islands in the summer in sufficient 

 numbers to become well known. Ti e limits beyond the summer 

 5-year-olds remain to be determined when the branded animals 

 shall have grown older. 



Arranged according to the above standards, the animals killed on 

 both islands fall as follows, and the numbers have been deducted 

 from the numbers of bachelors in each class in the estimates. 



Ages of Seals Killed on the Pribilof Islands During the Year Ended Aug. 



10, 1917. 



Age. 



Fall, 1916. 



St. raul. 



St. 

 George. 



Total. 



Summer, 1917. 



St. Paul 



St. 

 George. 



Total. 



Grand 

 total. 



Yearlings 



2-year-olds 



3-year-olds 



4-year-olds 



5-year-olds 



6-year-olds and over . 



Total , 



23 



447 



103 



2 



1 



113 



339 



48 



1 



1 



136 



786 



151 



3 



502 



1,077 



5 



65 



1,708 



1,509 



445 



3,820 



35 



1,857 



476 



18 



2,392 



5 



100 



3,565 



1,985 



463 



94 



6,212 



236 

 4,351 

 2,136 



466 

 94 



7,289 



