62 



U. S. BUREAU OF FISHERIES. 



The annual census of the fur-seal herd was taken in the summer of 

 1921. The report, by Edward C. Johnston, is printed in full on 

 pages 78 to 85. The increase in the size of the areas covered by 

 breeding seals has made it more and more difficult to secure an accu- 

 rate census. 



On Reef rookery, St. Paul Island, two counting towers were erected 

 before the seals arrived in the spring. These counting towers were 

 built in the form of a tripod witli the apex about 24 feet above the 

 ground. A runway, 6 feet in height, extended from the tripod to 

 the rear of the rookery, providing a safe means of reaching the tripod. 

 The counting towers were placed just above the high-water mark on 

 the beach and within the area occupied by the breeding seals. From 

 the top of the towers the observer was able to get an unobstructed 

 view of all the breeding seals and was not forced to divide his atten- 

 tion between the movements of dangerous bulls and the work in 

 hand. The experiment has proved successful, and additional count- 

 ing towers will be erected in 1922. 



The following is a comparative statement of the numerical strength 

 of the various elements of the herd in the years 1912 to 1921, 

 inclusive : 



General comparison of recent censuses of the seal herd on Pribilof Islands. 



Classes. 



Harem bulls 



Breeding cows 



Surplus bulls 



Idle bulls 



Young bulls (chiefly 



5-year-olds) 



6-year-old males 



6-year-old males 



4-year-old males 



3-year-old males 



2-year-old males 



Yearling males , 



2-year-old cows , 



Yearling cows , 



Pups 



Total. 



1,358 

 81,984 



113 

 199 



100 

 2,000 

 11,000 

 13,000 

 11,000 

 13,000 

 81,984 



215.738 268,305 



1,403 

 92,269 



105 

 259 



2,000 

 10,000 

 15,000 

 20,000 

 15,000 

 20,000 

 92,269 



1,559 

 93,250 



172 

 1,658 



9,939 



13,880 

 17,422 

 23,068 

 17,422 

 23,067 

 93,250 



294,687 



2,151 

 103,527 



673 



11,271 

 15,848 

 18,282 

 23,990 

 30,307 

 23,990 

 30,306 

 103,527 



363, 872 



3,500 

 116,977 



2,632 



11,167 

 15,494 

 15,427 

 19,402 

 24,169 

 33,645 

 24,245 

 33,046 

 116,977 



1917 



4,850 



128,024 



8,977 



2,706 



15, 397 

 14,813 

 16,631 

 19,507 

 26,815 

 38,013 

 26,917 

 38,018 

 128,024 



1918 



5,344 



142,915 



17,110 



2,444 



13,755 



11,941 



7,114 



9,117 



30, 159 



41,595 



30, 415 



41,608 



142,915 



417,281 468,692 496,432 524,235 552,718 



1919 



5, 158 



157, 172 



9,619 



2,239 



8,991 



5,282 



5,747 



13, 596 



33,081 



46,444 



33,287 



46,447 



157,172 



4,066 



167,527 



6,115 



1,161 



4,153 



5,007 



5,667 



10, 749 



39,111 



51,074 



39, 480 



51,081 



167,527 



3,909 



176,655 



3,301 



747 



3,991 

 4,729 

 6,780 

 14,668 

 41,893 

 50,249 

 43, 419 

 54,447 

 176,655 



581,443 



SPECIMENS FOR SCIENTIFIC PURPOSES. 



Upon request of the Colorado Museum of Natural History, Denver, 

 Colo., skins from one adult bull, two cows, and three pups were 

 shipped to the museum. Two of the pups were found dead on St. 

 Paul Island, and the remainder were found dead on St. George 

 Island. The collection was appraised at $39, which was paid by the 

 museum, and the amount in full was deposited in the United States 

 Treasury. 



FOXES. 



Although the fur seals are the most important feature of the 

 bureau's activities on the Pribilof Islands, the blue-fox herd is rap- 

 idly increasing in size and value. When commercial sealing was 

 resumed in 1918 fox food, which had been insufficient during 



