BARLOW ET AL.: AERIAL SURVEYS OF HARBOR PORPOISE 



49°N 



48° 



47° 



46° 



43° 



-T — \ 1 ^-y 



40° 



38° 



37° 



36° 



35° 



32^ 



-l_ 



REGION 



REGION 



REGION 



REGION 



REGION 4 



REGION 3 



_i_ 



UNITED STATES 



Bodega Head 



San Francisco 



REGION 2 



REGION 1 



Point Sur 



\ i Point Conception 



\?^pa 



_i_ 



132°W 131° 130° 129° 128° 127° 126° 125° 124° 123° 122° 121° 120° 119° 118° 117°W 



Figure 2.— Geographic regions used as strata in density estimation. 



by adding all appropriate transect segments to a 

 linear array and dividing that array into 10 equal 

 parts. 



When paired tests were not applicable, nonpara- 

 metric ANOVA models were used. For simple com- 

 parisons, the Kruskal-Wallis single-factor analysis 



of variance was used (Kruskal and Wallis 1952). For 

 two-way comparisons, we used a two-factor exten- 

 sion of the Kruskal-Wallis test (Scheirer et al. 1976). 

 For both tests, three replicate measures of density 

 were created for each cell by randomly assigning 

 transect segments as replicate 1, 2, or 3. 



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