Table 29. — Data for regression of the kill of i-year-old 

 male seals based on the kill of 3-year-old male seals 

 and mean round of the kill of 3-year-old male seals, 

 year classes 1953-6^, St. Paul Island 



Year 

 class 



Kill of 



3-year-old 



males before 



5 August 



Mean round 



of the kill of 



3-year-old 



males 



Adjusted kill 



of 4-year-old 



males before 



5 August 



(Y) 



males and 342 4-year-old males from 29 July 

 to 3 August 1968. The reduction was of 2 kill- 

 ing days because Svinday (4 August) was not a 

 working day. Table 29 shows the basic data 

 for this regression, as extended with new data 

 from the 1964 year class. 



The method of adjustment has been discussed 

 in previous reports and is summarized in the 

 footnote to table 19 in the 1967 report (Marine 

 Mammal Biological Laboratory, 1970). The 

 resulting regression equation is: 



Y ^ -47,42+0.39X1+13.95X2 



where: Y, Xx, and X2 are as indicated in 

 table 29. 



For the 1965 year class, Xi (kill of 3-year- 

 old males before 5 August) as adjusted is 

 20.7 thousand and X2 (mean round of kill of 

 3-year-old males) is 4,07, As in the basic 

 data, the mean round (X2) of 4,07 was con- 

 verted from the mean date of the kill (21.36* 

 July), The unadjusted estimate of the kill of 

 4-year-old males in 1969 is 17.4 thousand. 

 This estimate has a standard error of 2,0 

 thousand. The actual forecast must consider 

 the 3-year-olds spared from 3 to 5 August 

 and those taken in the postseason kill. Maxi- 

 mum and minimum numbers of seals that 

 might be added to the kill of 4-year-old males 

 in 1969 because of these factors are 1,300 

 and 400, respectively. Adding the average of 

 these figures to the unadjusted forecast yields 

 a final forecast by this method of 18.2 thousand. 



Table 30.— The observed kill of 3- and <4-year-old male seals, mean air 

 temperature, mean weight of living seal pups, and count of dead 

 pups, year classes 1950-64, St. Paul Island 



1/ Adjustments were made for year when the kill did not end 5 August. 

 2/ Estimated. 



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