CH. XXXI. SENSE OF SMELL IN BIRDS. 173 



seen the eagle do this ; and he has sometimes dis- 

 covered the grouse from a height and distance so 

 great as to make it appear impossible that he 

 should have distinguished so small an object. 



It is certain, however, that birds have a tolerably 

 acute sense of smelling, although I know that it has 

 been positively denied that ducks are guided by 

 their scenting powers in taking alarm, and that it is 

 by their quick sense of hearing only that they are 

 warned of the approach of danger. But this I 

 utterly deny ; for I have constantly seen wild-fowl, 

 when I have been sitting perfectly motionless in an 

 ambuscade, swim quietly towards me without the 

 slightest warning of my vicinity, till coming to that 

 point where my place of concealment was directly 

 to windward of them, they immediately caught the 

 scent, took wing, and flew off in as great alarm as 

 if I had stood up in full view. The same thing- 

 has occurred very frequently when I have been in 

 pursuit of geese, the birds invariably taking alarm 

 as soon as they came in a line with me and the 

 wind, and just as much so when I was motionless 

 and not making the slightest noise, as when I was 

 creeping towards them. The same sense of smell- 

 ing doubtless guides birds, in many cases, to their 

 food, but it is certainly not the sole or even the 

 principal guide of the ravens or the eagles. 



