60 



50 



^40 



O 



a 



30 



20 



X X 



X XX 



X— 1937 (^ FETUSES 

 •— 2035 $ FETUSES 



10 - 



1121 1121 



NOV DEC 



1121 

 JAN 



II 21 

 FEB 



II 21 

 MAR 



I I 21 

 APR 



II 21 

 MAY 



II 21 

 JUN 



II 21 

 JUL 



II 21 

 AUG 



Figure 13. --Lengths of 3,972 fur seal femses plotted by 10-day periods for 1958-62. 



Henry (Oceanography Department, University 

 of Washington, Seattle, Wash.). 



Fetal sex ratio and uterine horn of preg- 

 nancy.--ln the samples collected during 5 

 years, pregnancies occur most often in the 

 left horn, as shown below: 



Percent of 

 pregnancies 



Percent of 

 fetus sex 



Year Left horn Right horn Male Female 



The sex ratio has progressively changed 

 towards a greater proportion of female fetuses. 

 The apparent change may be real or a result 

 of sampling variation. 



Food Habits 



Throughout its range, the fur seal feeds 

 upon a wide variety of fish and squids. In the 

 past 4 years, 53 different food organisms 

 from the eastern Pacific and 28 from the 

 western Pacific have been identified. The 

 collection made by the United States in 1962 



^North Pacific Fur Seal Commission, Report of 

 Investigations from 1953 to 1961 (in press). 



35 



