APPENDIX F 
Calculations for the size of the pup 
class in 1947 from tag recoveries 
From actual tag recoveries on 5 areas 
The method used to estimate the number of pups is based on the 
fact that if 
t, were tagged on area i and 
nm; were sampled from area j which originally had a 
population a and 
tags were recovered on area j that had Been applied 
5 
AJ in area i; then on the average 
5 s,. N 
> a tj i at, Sal eeiass 
= ny 
The values nj, ‘> oF are known and hence there are 5 equations in 
ni 
5 unkmowns to solve for the N Summing the five N, yields the total 
i° 
population estimate. 
The five equations based on A-tags and composite returns of 
1950 and 1951 are as follows: 
420 Ni +_34, Not3. N+ 1G. N +_18 N= 5,557 
Ton 1 8373 2 723 3 307 4 Tog 5)? 

88 N, + 280 N,+_6_N,+ 5° N + _10 N_ = 5,040 
17941 8373 < 423 3 6307 4 31315 »5 
67 N, + _33 N, + 127_N, + 36 N, +92 N = 3,214 

17941. 8373. = 7423 32 6307 11315. 5 
18 N+ 6 No+ 5 Ni +_33 N +_ 30 N.= 876 
17941 7 38373 723 7 6307 * 21315 9 

