CERTAIN PHASES OF BIRD-LIFE. 345 



Such observations as the one noted in detail I have so frequently 

 repeated with widely-differing species as to satisfy me that what 

 may be termed " direct instruction " in flight is given to the young 

 birds by their parents. " Indirect instruction " also is noticeable, in 

 the fact that the parent-birds cease to feed their young, and so force 

 the latter to leave the nest and follow them. Once out of the nest, 

 they soon endeavor to walk on air, as it were, and, falling, open their 

 wings, and, as described, thus take the initial step. This ceasing to 

 bring the food to the young while yet in the nest is done in some 

 instances, I judge, only to draw them from the nest ; and then they 

 feed them as before, but not as frequently, which leads the young to 

 voluntarily move from point to point. The important fact must not 

 be lost sight of, too, that the young birds, when once out of the nest, 

 witness nearly every movement of their parents, and learn, un- 

 doubtedly, very much through imitation of their movements. 



For these reasons, I believe the acquisition of full flight-power is 

 gradually acquired ; first there is a mere " flapping " to prevent fall- 

 ing ; then short horizontal stages of aerial progression ; finally, a 

 steady, intelligent use of the wings, enabling the birds to execute the 

 highest type of flight within their capabilities, i.e., upward flight. 



In the case of birds of more complicated flight than those men- 

 tioned above, such as the falcons, where hovering is a necessary ac- 

 quirement, the truth of the assertion that flight is gradually acquired 

 becomes more evident from the fact (which I have very frequently 

 verified by observation) that the young birds for some time after 

 leaving the nest are fed by their parents. They commence procuring 

 food for themselves by chasing sparrows ; checking their moderate 

 flight when above a thicket, they rush upon the fleeing birds, more 

 frequently without success than with. Their first attempts at hover- 

 ing are miserable failures, and it is not until autumn that they are 

 enabled, by the complete control of their wings, to stay themselves in 

 mid-air, and, at the proper moment, dart with unerring aim upon some 

 luckless mouse. 



I have used the term " unerring," because it is customary so to 

 characterize this act of the falcons; but, having watched, with a pow- 

 erful field-glass, the hovering and darting of hawks, I have been forced 

 to consider the term far from correct, and that not more than one- 

 half, if as many, of the " strikes," on the part of the bird, are effectual. 



Following the young birds, of any species, from the nests, and 

 noting their movements, we find that the one prominent aim of their 

 lives, during their first summer, is the acquisition of food. They have 

 really nothing else to do, if we except escaping from the attacks of 

 their enemies, and this is taught them directly by their parents. I 

 judge that the great majority of birds that fall victims to birds of 

 prey and carnivorous mammals are young. To return to the feeding- 

 habits of birds. These appear to be acquired, by every bird, through 



