

Figure 14. --Opened body caviry of IG-year-old female 

 fur seal showing position of uterus and twin fetuses. 



Figure 15. — Reproductive tract partially removed. The 

 nonpregnant horn and its ovary are visible on the 

 knife blade. 



apparent direct effect on the fur seals but 

 presumably influenced the distribution of their 

 prey. 



The area north of the Aleutian Islands 

 between Unimak Pass and Bogoslof Island 

 in the vicinity of the 100-fathom curve, Unimak 

 Pass, and the western Alaska feeding grounds 

 south of Unimak Pass, form what is probably 

 one of the major summer and fall feeding 

 areas for Pribilof seals. Seals travel about 

 180 miles from St. George Island or 220 miles 

 from St. Paul Island to reach the feeding area 

 north of the Aleutians. The western Alaska 

 grounds are about 250 miles from St. George 

 Island or 290 miles from St. Paul Island. The 

 presence of post partum nursing females in 

 these areas is proof that seals travel from 

 the Pribilof Islands to feed. Nursing females 

 can be recognized by the milk in the mammary 

 glands, placental scar in the uterus, and 



corpus albicans in the ovary. They can be 

 expected to return to the islands to nurse 

 their pups. 



Few seals collected near the Pribilof Islands 

 had food in their stomachs. Kenyon (1956) 

 found that the number of seals on St. Paul 

 Island with appreciable stomach contents was 

 less than 0.1 percent of those examined. 

 Figure 19 illustrates a series of zones 30 

 miles wide, concentric at a point midway 

 between St. Paul and St. George Islands and 

 numbered from this point. These make possible 

 a comparison of the volume of stomach con- 

 tents in relation to distance from the islands. 

 The percent of stomachs containing food, a 

 trace of food,* or empty is shown for each 

 zone. Stomachs from zones 1 to 3 were largely 



* Less than 5 cc. of food in a stomach is considered 

 a trace. 



40 



