TRAVELS OF WATERFOWL 



child) are much more sharply defined than responses to the environment, it 

 is quite reasonable that Lorenz should first have described this process in 

 the parent-child tie. But surely, as Thorpe declares, this process of rapid 

 learning relates the infant to its environment in the same manner that it 

 conditions it to its mother. 



I suggest further that this recording of visual perceptions is not limited 

 to early life but is a constant and life-lasting process relating the bird to its 

 world. The retention of visual experiences is the key to life's continuity, by 

 which the past is ever related to the present. Each hour and day of life the 

 visual experiences of the present create the past upon which the future de- 

 pends. Through the traces it has left on the memory, a landscape seen only 

 briefly is familiar after an absence, whether it be the natal slough or a stop- 

 ping place on the wayside of migration. The function of memory might be 

 likened to a reel of movie film. The memory, like the film, records images in 

 individual segments to make up the continuous whole. New records are 

 made as the bird pioneers into new regions. Then, as a duck flies over a 

 countryside it has visited before, the pattern of the landscape, as seen each 

 instant, is familiar. Once out of sight, the scene is stored away to be recalled 

 only by the next trip over the same place. As in the movie, the landscape 

 meeting the eye at the present instant has meaning only in the context of 

 the familiar scenes that have just been viewed. The present becomes the 

 past the moment it is seen. 



Here in my hand is a Baldpate hen, trapped on our Decoy where she was 

 banded last fall. She is a spring migrant lingering briefly at a familiar stop- 

 ping place on the way to her home. And what of her mate? She distinguishes 

 him from all males of the kind, and the two join on the pond after she is 

 free from my hand. This process of retention must go on through all the 

 days of life, ending only when life itself comes to a close. We measure its 

 strength when we watch the response of the duckling to its mother or when 

 we record the return of a bird to the nesting place ; but it must hold that in 

 all periods of the life history, each individual lives efficiently in the present 

 because of its link with the past. 



So far I have spoken of the visual world, but we must not forget physical 

 experiences that are perceived not only by the eye, but by other senses as 

 well. For example, the catching of a duck is felt as well as seen. The two 

 objects related to catching are man and hand-net. When I walk about the 

 pen, my simple presence evokes no response from the ducks and geese. Nor 

 do they react to the net which hangs on the wall. Even when I stand close 



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