APPENDIX B -- SAMPLE SHORE AND DORY COUNTS EXTENDED TO ALL OF AMCHITKA 
Shore counts were most frequently and carefully made along the 
3-mile coastline of Kirilof Point. The mean of five counts made in 
January, February, and March is 20 (extremes 16 and 26). If the mean 
is applied to the 120 miles of shoreline, the total estimate from 
Amchitka becomes approximately 800 otters. The mean of five shore 
counts made in April and May is 51 (extremes 40 and 62). The mean 
applied to the 120-mile shoreline gives an estimate of 2,040 otters 
for all of Amchitka. 
The purpose of including this information is to demonstrate that 
such sample shore counts must be evaluated with considerable care and 
in the light of many other observations. 
These shore counts demonstrate that movements of otters in re- 
sponse to weather and food availability may introdute considerable 
variability in the results of such counts. 
Since otters tend to concentrate around points, care must be 
taken when generalizing on the basis of sample shore counts. 
The average of individual counts, made on 4 days of counting 
otters from the dory, have been combined (Appendix A). The total ob- 
tained in this way from (and including) East Cape to (and including) 
Crown Reefer Point is 292. When this 13.5-mile stretch is considered 
a sample area and applied to the air survey track distance around 
Amchitka of 82 miles1 , the estimated otter population becomes 1,772. 
This figure is surprisingly close to our total aerial count of 1,560 
otters. 
Excluding East Cape and Crown Reefer Point (areas of otter con- 
centration) from dory counts and using 12.5 miles of coastline for 
the counted sample, then 238 otters are included. Applying this figure 
1/ At our request the U. S. Coast and Geodetic Survey office in 
Seattle measured the highly irregular shoreline of Amchitka and 
gave us the approximate distance of 120 nautical miles. For the 
present purpose, however, distances are measured along the track 
of the surveying aircraft over the water. By using this method 
the distance around Amchitka is 82 nautical miles. For the 
purpose of applying corrections obtained from sample dory surveys 
to aerial counts this method of distance measurement is more satis- 
factory. Inaccuracies in distance measurements of sample coastal 
areas caused by the extremely irregular coastline of Amchitka are 
otherwise difficult to evaluate. 
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