THE FUNCTION OF MEMORY 



to the net, there is no response. But when I grasp the net in my hands, the 

 birds scurry away and shortly are safe in the center of the pond. Nearby is a 

 bucket I have forgotten while I work at the Decoy. Neither I nor the bucket 

 draws any response from the ducks ; but the instant I step over to pick it up, 

 the birds walk toward me or to the corner of the pond where they usually 

 are fed. Here are sharp associations. Man plus net equals catching experi- 

 ence; man plus bucket equals food. The two objects must be acting together 

 to draw responses, being neutral features of the landscape when isolated 

 from each other. 



I have considered only the relation between the past and the present 

 in the continuity of a waterfowl's life. There is evidence of deliberate ac- 

 tions which, although hinged to the past, are aimed at the future. An ex- 

 ample is the behavior of our Whistling Swans, old "pensioners" that live at 

 Delta because shot wounds will not permit them to take wing. Their hearts 

 are wild, and when spring or autumn winds blow, they become restless. 

 Again and again, sometimes for more than an hour, they race across the 

 pond in frantic, futile attempts to reach the freedom that calls. In this ac- 

 tion, a swan walks deliberately to the downwind end of the pond, faces into 

 the wind, utters the pre-flight call of all Whistling Swans, then starts his 

 race across the water. The destination is the far shore. This attained, he 

 flaps his wings, preens for a moment, then walks back to the south end of 

 the pond. It seems to me that when he goes toward the downwind edge of 

 the pond, all his past experiences press him to the place where he will start 

 his flight run. Moreover, he not only selects the downwind position, but 

 many times I have watched these great birds choose the exact point on the 

 shore that will give them the longest run across the water, just as the pilot 

 of an aircraft measures Cadham Bay for his take-off. A difference of a few 

 feet at the start means several more yards for the run, and the birds invari- 

 ably stand where they face the widest stretch of water. Thus, so it seems, 

 past take-off experiences direct the swan to the point opposite the longest 

 span of water where the flight run will take place. 



To carry this point further, let us examine the behavior of a nesting 

 duck. She sits on her loafing spot, from which one of several inner stimuli 

 may bend her to move to a special destination. She may fly to her source 

 of grit on the lakeshore, to a choice feeding place in a neighboring slough, 

 or to her nest in the meadow. The impending movement will be in response 

 to the stimuli from a gritless gizzard, an empty crop, or a full-formed egg 

 in the oviduct. She has no control over these stimuli; she can only respond 



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