Fear m Birds. 93 



people passing in and out at all times; and when 

 the weather grew warm he would swell out his 

 breast and coo mournfully by the hour for our 

 pleasure. 



We can, no doubt, learn best by observing the 

 behaviour of nestlings and young birds ; neverthe- 

 less, I find much even in the confirmed habits of 

 adults to strengthen me in the belief that fear of 

 particular enemies is in nearly all cases — for I will 

 not say all — the result of experience and tradition. 



Hawks are the most open, violent, and persistent 

 enemies birds have ; and it is really wonderful to 

 see how well the persecuted kinds appear to know 

 the power for mischief possessed by different rap- 

 torial species, and how exactly the amount of alarm 

 exhibited is in proportion to the extent of the danger 

 to be apprehended. Some raptors never attack 

 birds, others only occasionally ; still others prey only 

 on the young and feeble ; and, speaking of La Plata 

 district, where I have observed hawks, from the 

 milvago chimango — chiefly a carrion-eater — to the 

 destructive peregrine falcon, there is a very great 

 variety of predatory habits, and all degrees of cou- 

 rage to be found ; yet all these raptors are treated 

 differently by species liable to be preyed on, and 

 have just as much respect paid them as their 

 strength and daring entitles them to, and no more. 

 So much discrimination must seem almost incredible 

 to those who are not very familiar with the manners 

 of wild birds ; I do not think it could exist if 

 the fear shown resulted from instinct or inherited 

 habit. There would be no end to the blunders of 



