Logic applying to an individual frequently has 

 little relationship to the thrift and survival of 

 a life community." 



On the Pribilof Islands, biologists and bi- 

 ometricians have the opportunity to guide the 

 management of fur seals according to popula- 

 tion principles. Despite occasional hesitation 

 and uncertainty, the female population is being 

 reduced to test the theory that the seal herd 

 was no longer growing and that it would reach 

 its maximum yield at a lower level. 



The survival of year classes has been both 

 high and low since the reduction of females 

 began in 1956. The area occupied by rookeries 

 is apparently decreased but, until recently, 

 population estimates did not indicate that the 

 population was reduced. Sources of error, 



mostly inflationary, in the information used 

 to make population estimates are now being 

 tested. The annual mortality in the sea and, 

 therefore, the survival to age 3, when the year 

 class first enters the harvest, cannot yet be 

 predicted. 



The problems of predicting survival and of 

 estimating accurately the number of adult 

 females and the number of pups produced are 

 the most important ones that research on fur 

 seals must solve. The following pages record 

 the progress made on these problems and on 

 related studies in 1963. 



The 1963 field season on the Pribilof Islands 

 extended from June to October. Arrivals, de- 

 partures, and affiliations of research workers 

 follows: 



Name 



Richard S. Peterson 1 



Peter A. Dzikiewicz 1 



Robert L. DeLong 1 

 Kenneth E. Thompson 1 



Alton Y. Roppel 

 Richard K. Stroud 1 



Frank B. Reberger' 



John C. Haxton 1 



Ancel M. Johnson 



Arrival Departure 



10 June 



24 June 



1 July 



if r t 



22 " 



7 Oct. 



9 Sept. 



26 Aug. 



3 Sept. 



9 " 



16 " 



29 Aug. 



Affiliation 



Bureau of Commer- 

 cial Fisheries and 

 Johns Hopkins 

 University 



Bureau of Commer- 

 cial Fisheries 



Work 



Behavior of fur 

 seals 



Fur seal re- 

 search, gen- 

 eral 



Population dy- 

 namics of fur 

 seals 



Mark C. Keyes 



8 July 19 Aug. 



Mortality of fur 

 seals 



Charles A. Rohrmann 

 Ford Wilke 



24 Sept. 

 9 Sept. 30 Sept. 



Fur seal re- 

 search, gen- 

 eral 



George Schaller 

 Paul A. Colinvaux 



17 June 27 June 



26 July 



Independent 

 Duke University 



Fox census 



Evolution of 

 Bering Sea 

 land bridge 



Edwin Horn 

 William Horn 

 Alex Peden 



it n 



5 Aug. 



12 Aug. University of Brit- 



ish Columbia 



Collect tide pool 

 fishes 



