FUR-SEAL CENSUS, PRIBILOF ISLANDS, 192L 



By Edward C. Johnston. 



In taking the census of the fur-seal herd on the Pribilof Islands in 

 1921 it was necessary for the writer to make two trips to vSt. Paul 

 Island. It was intended to spend a few days on St. Paul Island in 

 a preliminary examination of the rookeries, but adverse weather 

 conditions prevented arrival there until the evening of July 14. 

 The bull count began on July 16. Thanks are due to the commanding 

 officers of the Coast Guard cutter Unalga, the U. S. S. Saturn, and 

 the Bureau of Fisheries vessel Eider for their courtesies in providing 

 transportation at the proper times. 



The superintendent of the Pribilof Islands, A. H. Proctor, and 

 the a^ent and caretaker of St. Paul Island provided necessary assist- 

 ance in census work and also in erecting tripods before the arrival 

 of the seal herd in the spring. Henry Mygatt, assistant to the 

 agent of St. Paul Island, and J. M. Orchard, school-teacher, rendered 

 valuable assistance at various times. 



Conditions on the islands made it possible to spend but 13 days 

 in all upon St. Paul Island. The rookeries could not be visited more 

 than twice — once for the bull count and once for the pup count. 

 Consequently field observations and preliminary counts of seals 

 were not made on St. Paul Island as they were on St. George Island 



TRIPODS AND MARKERS. 



In the spring of 1921, before a great number of bulls had arrived, 

 two tripods or counting towers were erected on Reef rookery, St. Paul 

 Island. The tripods were 24 feet in height, made by joining three 

 uprights at the apex and properly bracing them. Runways 1 foot 

 wide and 6 feet above the ground extended back beyond the harem 

 areas. The tripods were placed at the crest of the beach line, so that 

 all parts of the harem area in the immediate vicinity were visible. 

 The seals were not disturbed in the least by the presence of the 

 tripods. In fact, the piles of rock at the bases of the tripods were 



Elaygrounds for large numbers of pups. A harem was located 

 etween the legs of one tripod. 



An increase in the height and width of all runways should be made 

 on sections extending over any harems; that is, the sections adjoining 

 the tripods. The height should be 9 feet and the width 2 feet. 

 An old narem bull can reach nearly 6 feet without effort. A handrail 

 or rope along the high section of the runways would be a convenience 

 but not a necessity. 



There is no doubt that these two tripods made the harem count 

 much more accurate in the areas visible from them. The erection 

 of similar counting towers at points on other rookeries at the earliest 

 possible date is strongly recommended. It would eliminate the 

 necessity of counting from a boat, a method very uncertain on account 



78 



