72 "U-S. BUREAU OF FISHERIES 



FUR-SEALS AND BIRDS FOR EXHIBITION 



Three live fur seals, 2 male and 1 female, from St. Paul Island 

 and 19 rosy finches from St. George Island were forwarded on the 

 Penguin in September for the National Zoological Park, Washing- 

 ton, D.C. One of the fur seals and 3 of the birds died en route. The 

 remainder arrived at the Zoo in Washington on September 27, hav- 

 ing been sent by express from Seattle. 



Of the 3 fur seals delivered to the National Zoological Park in 

 December 1928, 1 died a few weeks after arrival and another in Sep- 

 tember 1931. The surviving fur seal of that group on July 31, 1932, 

 gave birth to a pup, which was stillborn. So far as known, this is the 

 first fur seal born in captivity. 



COMPUTATION OF FUR SEALS, PRIBILOF ISLANDS, 1932 



Bj' HaeKY J. ClIRISTOFFEES 



The main purpose of a yearly computation of fur seals at the 

 Pribilof Islands is to determine as accurately as possible the number 

 of 3-year-old males, the killable seals, returning to the islands and 

 whether sufficient numbers of this age class are being reserved for 

 breeding purposes. 



Through investigations during a series of years it has been deter- 

 mined that the average J^early rate of growth of the herd is approxi- 

 mately 8 percent. For the last several years there have been abnor- 

 mal increases in the number of 3-year-old male seals at the islands; 

 from 1928 to 1931, inclusive, it was possible to kill, consecutively, 

 numbers representing increases of 26 percent, 33 percent, 9 percent, 

 and 15 percent over the take of the previous year, without endanger- 

 ing the steady development of the herd. In 1932, however, there was 

 no increase over the preceding year in the number killed. 



The above-mentioned increases in killings are much greater than 

 would normally have been expected. They may be attributed partly 

 to the birth of a larger number of pups because more males were 

 left for breeding purposes, and partly, no doubt, to unusually good 

 conditions at sea, which reduced the mortality rate for the first 3 

 years of the life cycle. If the number of 3-year-old males continues 

 to increase as it has in recent years, the 8 percent increase for the 

 entire herd, as previously determined over a period of years, will no 

 longer be applicable. 



During the first half of the 1932 sealing season it appeared that 

 there would be a large increase in the take. Through July 9 there 

 had been taken 24,229 seals, as compared with 21.812 on the same 

 date in 1931. From that date on, however, the killings were less 

 than in the previous season, with the result that the total take of seals 

 for 1932 was 49,336, of which 47,625 were classed as 3-year-old 

 males, as against a total of 49,524, including 47,767 3-year-old males, 

 in 1931. 



The latter part of the season was marked by rather stormy 

 weather, very unfavorable for the hauling out of seals. The}' seem 

 to j^refer to liaul out in calm, warm weather, and they usually return 

 to the water wlien there is a driving rain. This may account for the 

 short take of skins. It is very likely that weather conditions affect 



