LEARNED RESPONSE TO THE ENVIRONMENT 



feeding actions are directed almost entirely toward the food trays. Hard- 

 boiled egg, let us note, is a new food to Canvasback, unknown to its species 

 in the wild. 



In a few days the diet of the downy Canvasback is changed, egg being 

 replaced by a mash of mixed cereals, dried greens, and powdered animal 

 products — again, a new food in the natural history of Canvasback. This is 

 accepted readily. Here, with mash, the youngsters soon demonstrate learned 

 discrimination. They show a dislike of ground corn, expertly separating this 

 from other ingredients of their meal. I suspect that this same approach to 

 food takes place in the wild; through the experience of trial and error the 

 duckling finds the food most useful to it. True, the youngling follows its 

 mother, being led by her to choice feeding localities. Some foods may be 

 learned by the example of her feeding behavior, but it is clear that much 

 of the nourishment is found independently. Many times I have seen the 

 mother diving, while the young fed at the surface, no doubt on some other 

 food. 



It is the same with flight. The bird flies instinctively, but it must learn 

 to relate this act to its environment. For instance, a duck must learn the 

 fine art of alighting. Young on their first flights are often hesitant and ap- 

 parently bewildered when approaching a landing, often coming down with 

 a hard splash. They must learn to direct the course of their aerial travels. 

 The movements of the tail-rudder are often so awkward in new-flying ju- 

 veniles that these actions clearly distinguish them from adults. In the 

 making of a turn, for example, the tail may be tipped too far to one side; 

 then the bird over-compensates with "reverse rudder" and the tail tips too 

 far in the opposite direction. The use and dangers of the wind must be 

 learned. Down-wind landings are such frequent mishaps in young water- 

 fowl that one must believe that it is only through experience that they learn 

 to alight facing the wind. They learn to relate their speed of flight to ter- 

 restial objects so that they do not overshoot their mark. During these early 

 days of flight there develops the unity of instinct and learning by which the 

 bird masters its aerial environment. 



It is much the same with other basic movements. A duck swims instinc- 

 tively, but it must learn where to swim. On land, when it travels there ( as 

 when a hen walks through the grass to her nest), it walks instinctively, but 

 it learns where to walk. Its courtship and reproductive activities are in- 

 stinctive, but it learns the companions toward which these activities are 

 directed. Thus, while a duck's behavior is ruled by instinct, its place in the 



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