896 



SCIENCE 



[N. S. Vol. XXXVI. No. 939 



however, lay in its value as a measure of de- 

 cline, and for this purpose the results vcere as 

 satisfactory as a complete count would have 

 been. 



By the treaty of July 7, 1911, the United 

 States secured, through the cooperation of 

 Great Britain, Eussia and Japan, the aboli- 

 tion of pelagic sealing. The herd was thus 

 freed from the drain upon its breeding stock 

 and hope for its restoration was revived. The 

 season of 1912 was the first under the new 

 treaty. It became important therefore to 

 know the exact status of the herd and a full 

 count of the pups was undertaken and suc- 

 cessfully accomplished by the writer. The 

 rookeries of St. Paul Island gave 70,035 ; those 

 of St. George Island, 11,949— a total of 81,- 

 984 pups. As each pup accounts for a mother 

 seal, there was a like number of breeding 

 cows. The harems numbered 1,358, an aver- 

 age of 60 cows to each, giving a total of 165,- 

 325 breeding seals and young, with non-breed- 

 ing seals estimated at 50,412, or 215,738 ani- 

 mals of all classes. 



Omitting the non-breeding seals, which can 

 only be estimated, and dealing only with the 

 breeding seals, we find an excess of 62,685 ani- 

 mals over the estimate of 1909. Approxi- 

 mately 15,000 cows reached the rookeries in 

 1912 and brought forth their young, which 

 under pelagic sealing would have been killed 

 at sea. These with a like number of pups 

 swelled the herd and account for 30,000 of 

 the excess. The remaining 32,685, made up 

 of cows and pups, are accounted for by under- 

 estimates in 1909, from applying to large 

 rookeries averages obtained from smaller 

 rookeries. The average harem for all the rook- 

 eries in 1912 is 60 cows; that used in making 

 the census of 1909 was 36. If we deduct the 

 15,000 cows saved through cessation of 

 pelagic sealing, the average harem for 1912 

 drops to 48. Applying the difference between 

 this and 36 as a correction to the census of 

 1909 would add to it 16,644 cows and an equal 

 number of pups, 33,288 in all, a figure siiifi- 

 ciently near to 32,685 to show that it is fairly 

 accurate. As a matter of fact the herd has 

 not changed much since 1909. The pelagic 



catch has merely taken, in the past three sea- 

 sons, a number equal to the annual increment 

 of gain, that is, the excess of young breeding 

 cows over the natural loss in adults due to old 

 age. By this normal increment of gain, 

 which is about ten per cent, yearly, now pro- 

 tected from loss, will the herd rise to its 

 former populous condition. 



The counting of the fur seal herd is a simple 

 but at the same time laborious process. The 

 animals occupy six to eight miles of shore 

 front, in a belt, varying in width with the 

 character of the ground, but never more than 

 150 to 200 feet, often much less. The work 

 must be done in the first week or ten days of 

 August, between the close of the breeding 

 season and the time when the pups become ac- 

 customed to the water. The adult animals 

 are driven off by native helpers. The person 

 counting and his assistant cut off a pod or 

 group of pups, numbering 50 to 100, at a rook- 

 ery end, forcing it along the beach for a dis- 

 tance of one or two hundred feet. The ani- 

 mals string out in a line, the older and 

 stronger forging ahead, and the counting is 

 done by twos and in groups of threes and 

 fours while they are scattered. It is like 

 counting sheep as they pass through a gate. 

 A second pod is cut off and treated in the 

 same way, and so throughout the length of 

 the rookery. In the end the entire rookery 

 population has merely been shifted along the 

 beach a short distance, the adult animals re- 

 turn and conditions are soon readjusted. At 

 certain places close search must be made for 

 animals asleep or hiding in the crevices of the 

 rocks. Through failure to get all of these at 

 times the counts are slightly under the exact 

 facts. Count must also be made of the dead, 

 of which a number — 1,060 for all the rooker- 

 ies — were found, such deaths being incident 

 to exigencies of rookery life. The counting 

 of the 82,000 pups occupied eight days, the 

 largest single day's work being 20,000. 



The process sounds simpler than it really is. 

 The adult animals are always more or less 

 dangerous. The pups themselves have any- 

 thing but gentle dispositions and their teeth 

 are sharp enough to penetrate rubber boots. 



