The north and south sides of zone 9 should perhaps be 
considered together, as they are separated only by a road. Killing 
began on the north side 12 days before proceeding on the south side. 
Therefore, many of the unemployed birds which frequented both sides 
of the road were eliminated while killing was being conducted on the 
north side only. This doubtless explains the difference in calcu- 
lated proportions of unemployed birds on the two sides of the road. 
If the data for the north and south sides are combined, the ratio of 
unemployed birds to breeding birds in zone 9 is 148:100. 
As explained above, the kill figures for unemployed birds 
(and thus also the ratios of unemployed birds to breeding birds) are 
minimal. In order to determine the size of the unemployed popula- 
tion, we must add to these figures the following: (1) The number of 
breeding birds which escaped the kill (since it was arbitrarily 
assumed that all breeding birds were killed, the total of unemployed 
birds must be increased by this number); (2) the number of unemployed 
birds which escaped the kill; and (3) the number of unemployed birds 
at sea which will utilize the area later in the season. None of 
these figures are known, and it is not possible, with the information 
now available, to make reasonable estimates for them. 
Table 9.--Breeding Population, Total Kill, and Calculated Kill 
of Unemployed Birds in Albatross Elimination Area. 

Ratio of 
Calculated unemployed 
Number Breeding Number unemployed to breeding 
Area of nests population killed birds killed birds 
Zone 8 89 178 277 99 56:100 
(blackfoots) 
Zone 8 632 1,264 3,160 1,896 150: 100 
(Laysans) 
Zone 9 3,331 6,662 18, 106 11,444 172; 100 
(north) 
Zone 9 1,076 2,152 3,759 1,607 75: 100 
(south) 
Zone 7 326 652 4,739 4,087 627: 100 
Total 
(Laysans only) 5,365 10, 730 29,764 19,034 177: 100 
One factor which might tend to increase the apparent propor- 
tion of unemployed birds is the killing of birds which have settled 
temporarily on the kill area, but which normally utilize other territory. 
This is believed to be negligible for the following reasons: (1) There 
was no neticeable decrease of unemployed birds in other parts of the 
island, even in areas contiguous to the kill area (in zone 7, for 
example); (2) the number of banded birds killed, which had been banded 
in other areas, was very small (unfortunately, sufficient data are not 
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