70 



NORTH AMERICAN FAUNA 68 



as great as 50 fathoms for food may be possible but otters are 

 rarely seen in water as deep as 30 fathoms (180 ft.). No specimen 

 is available to give positive evidence of food gathering at depths 

 greater than 20 fathoms (120 ft.)- 



Our observations tend to confirm the conclusion of Barabash- 

 Nikiforov (1947) that **the greatest depth to v^hich it can go is 

 50 meters [164 ft.]" 



WALKING AND RUNNING 



Progression on land is similar but less agile than in other muste- 

 lids. The long, outer 5th digits of the hind flippers, v^hich par- 

 ticularly aid progression v^hen the otter swims on its back, hinder 

 progress on land. Snow (1910, p. 275), however, exaggerated this 

 hindrance when he wrote : 



The use, however, of the hind limbs is very limited, the toes appear to lack 

 all muscular power, and the otter cannot place its hind-feet flat upon the 

 ground; when it attempts to walk, the toes are doubled back under the soles. 



As figure 32 illustrates. Snow's statement is not true. He 

 probably received his impression from otters that were cornered 



Figure 32. — Because the fifth digits of the hind flippers are long, the sea otter 

 walks with a somewhat clumsy rolling gait. It moves somewhat more slowly 

 than normal human walking speed. (KWK 62-10-29) 



