The forecast of returns from the 1959 year 

 class is very similar using either relationship. 

 Substituting E = 672 (the present estimate of 

 the 1959 year class on St. Paul Island) in 

 equation (1), it is seen that Nm = 45.4. Using 

 equation (2), the estimated Nm is 46.0. 



FORECAST OF THE KILL OF 4-YEAR-OLD 

 MALES IN 1963 



Three forecasts of the kill of 4-year-old 

 males in 1963 are available. They are de- 

 rived from the estimated escapement of 

 3-year-old males in 1962, from the pup popu- 

 lation-return relationship, and from the dead- 

 pup count- return relationship. Allowing for 

 a 10 percent overwinter mortality and a 5 

 percent escapement in 1963, the resulting 

 estimates are: 



(1) 1962 escapement = 85 percent 



of 8,726 7,400 



(2) Pup population-return relationship 



Estimated total return 46,700 (average 

 of two methods) 



1961 and 1962 kill 29,300 



85 percent of balance 14,800 



(3) Dead-pup count-return relationship 

 Estimated total return 67,300 

 1961 and 1962 kill 29,300 



85 percent of balance 



32,300 



Since (1) and (3) appear less reliable, the 

 median estimate of 14,800 is probably the best 

 available. 



FORECAST OF THE KILL OF 3- YEAR-OLD 

 MALES IN 1963 



The forecast can be based on (1) the dead- 

 pup count-return relationship and (2) the pup 

 population-return relationship (in this case 

 the estimate has to be based on the recover- 

 ies of tagged 2-year-olds). 



The returns of the 1960 year class based on 

 (1) were estimated above as 52,100. The esti- 

 mate of the 1960 pup population on St. Paul 

 Island based on tag recoveries in 1962 is 

 415,000. However, the estimates based on re- 

 coveries of tags from 2-year-old males have 

 been unsatisfactory. The estimates, the corre- 

 sponding estimated returns from equation (2) 

 above, and the actual returns are shown in 

 appendix table 5. The correlation between the 

 estimate and the actual return is -0.4 2. 

 This is inadequate as a basis for predic- 

 tion. 



An alternative approach has been based on 

 the pup population estimate of the 1959 year 

 class which, for St. Paul Island, is 672,000. 

 In 1959, the kill of females on St. Paul Island 

 totaled 24,000. This should be accompanied 

 by a decline in the number of pups born of 

 about 15,000 (.6 x 24,000). If the 1960 pup 

 population is approximately 657,000, the es- 

 timated return is 48,100. 



The average of this estimate and the estimate 

 from the dead-pup count is 50,100. As done 

 previously, the actual kill of 3-year-old males 

 may be estimated as 60 percent of 50,100 for 

 31 July termination, and 80 percent for 15 

 August termination. The resulting estimates 

 are 30,000 and 40,000, respectively. The total 

 kill will also include some 2- and 5-year-old 

 males. In the past 5 years, the kill has 

 included an average of 2,400 males of these 

 ages. 



Hence, the total male kill for St. Paul Island 

 is forcasted as follows: 



Age 



2+5 



Total 



31 July termination 2,000 30,000 15,000 47,000 



15 August termination 3,000 40,000 15,000 58,000 



If this is 80 percent of the total kill for the 

 Pribilof Islands, the corresponding forecast 

 for both islands is: 



31 July termination 59,000 



15 August termination 72,000 



59 



