time and that knowledge of these patterns 

 contributes to recognition ability during the 

 period when female and pup are associated 

 on a rookery. It is granted that olfactory or 

 other cues may contribute to this recognition. 

 Mother-young mutual calling as the former 

 returned from feeding atsea was also recorded 

 on tape. Preliminary indications show that 

 both male and female fur seals respond 

 positively to play back of certain charac- 

 teristic calls, thus giving hope that a series 

 of carefully planned observations may allow 

 the determination of the relative extent to 

 which olfactory and auditory cues contribute 

 to recognition between individuals living within 

 the elaborate fur seal social structure. The 

 recordings made this summer are to be used 

 in preparing test tapes to be played to isolated 

 seals in a later series of experiments. 



Reeder is also conducting a study to deter- 

 mine age of fur seals from calcium and 

 phosphorous depositions. Skulls, baculae, and 

 flippers were collected and sent to Reeder for 

 this purpose. 



Tongues and larynxes from fur seals of 

 several age classes, from fetuses to age 21 

 years, were collected and sent to Jean A. 

 Pierard, Department of Anatomy, New York 

 State Veterinary College, Cornell University. 

 Pierard is performing a comparative study of 

 tongues and larynxes from animals in the or- 

 der Carnivora. 



An experiment in internal marking of fur 

 seals through fixation of tetracycline antibiotic 

 (terramycin) in the bones and teeth was con- 

 ducted in 1962. This marking method has been 

 successfully used by fishery biologists in 

 studies of age and of growth rates. 



Two female pups were injected peritoneally 

 on 8 July with 145 milligrams of tetracycline 

 per kilogram of body weight, made up by 

 dissolving 45 milligrams of the solid per 

 cubic centimeter of sterile distilled water. 

 The animals were killed on 18 July and 

 frozen. Douglas Weber of the serology section 

 of the Seattle Biological Laboratory will 

 examine the pups for antibiotic fixation. 



SUMMARY 



Males 



1. Beginning on 2 July a total of 53,680 

 male seals were taken on the Pribilof Islands 

 in 1962; 43,203 were taken on St. Paul Island 

 and 10,477 on St. George Island. Except for 

 efforts to take 4-year-old males during the 

 female kill 13-24 August, the male kill was 

 terminated 5 August. Age classification of the 

 kill in percent was: St. Paul Island, 4, 61, 33, 

 and 2, ages 2-5, respectively; St. George Island, 

 6, 56, 36, and 2, ages 2-5, respectively. 



2. The peak of the kill occurred during 

 round 6 (22-26 July) when 8,577 males were 

 taken on St. Paul Island. The 1962 kill pattern 

 followed that of years before 1960 and 1961. 

 Kills which draw on a relatively strong 3- 

 year-old class, as in 1960 and 1961, have a 

 late peak round. 



3. Probably, at least the same proportion 

 of increase in the male kill was possible for 

 the period 1-15 August 1962 as in 1961. If 

 this assumption is correct and the kill had 

 been extended from 5 to 15 August, the total 

 of all ages would have been 60,674, a figure 

 16 percent less than the 72,500 predicted 

 for 1962. 



4. No change has been detected In the 

 return of males that is known to be a result 

 of the removal of females. 



5. The pup population, estimated from tag 

 recoveries from males, for the Pribilof Islands 

 for 1958 and 1959 was 729,000 and 838,000, 

 respectively. Estimates based on tagged males 

 were much higher than those based on tagged 

 females. Results of the fall pup sampling pro- 

 gram showed that additional development of 

 this technique is necessary before it will pro- 

 vide a reliable estimate of the pup population. 

 The tag lost to tagged ratio increased in 1962 

 for the 1957 through 1959 year classes. The 

 ratio for the 1960 year class was the highest 

 ever recorded for recoveries of tags made 

 from 2-year-old males. 



6. The number of bulls counted decreased 

 from 14,006 harem and 14,280 idle in 1961 to 

 12,674 harem and 11,759 idle in 1962. 



53 



