LEARNED RESPONSE TO THE ENVIRONMENT 



Several farmers on the Portage Plains have told me of their experience 

 in moving duck nests during spring cultivation. When the hen is flushed in 

 front of the tractor, the farmer lifts the nest carefully and moves it to a new 

 location, where straw is often thrown over it for cover. Many times, accord- 

 ing to these accounts, the hen returns to accept the nest in its new location 

 and continue her incubation. Sowls (1951:56) gives an account of one 

 Pintail hen which tolerated the moving of her nest four times. It was moved 

 about seven feet (the width of the cultivator) each of the first three times 

 and twenty feet on the fourth shift, so that when the farmer, Murray Wer- 

 biski, showed Sowls the incubating hen, her nest was at least forty-one 

 feet from its original location. 



Ducklings reared by foster mothers learn to adapt themselves to parents 

 of entirely different species (Lorenz, 1935, 1937). A brood of Gadwall 

 hatched and reared at Delta by a White Leghorn hen accepted her as their 

 mother and learned some of her gallinaceous calls, to which they responded. 

 It is easier to cite examples of the duck's ability to learn than it is to 

 establish the point beyond which learning ceases to function. For example, 

 the female is aware of the location of her nest in the intricate grassy pattern 

 of the meadow, but she does not learn the identity of her eggs. Some nesting 

 females have been known to sit for long periods on stones. A brood mother 

 learns the identity of her youngsters, but she cannot count them. When a 

 brood is disturbed, the hen may return to retrieve only a part of her family. 

 If others are beyond sight and sound, one or two young will satisfy her 

 maternal instincts and she does not seek out the remainder of her family. 

 A duck or goose with one wing permanently pinioned by amputation does 

 not learn that it is unable to fly; when pursued it makes futile attempts to 

 take wing. 



It is not the purpose here to make a thorough analysis of learned be- 

 havior.* I simply wish to show how the bird learns its position in its en- 

 vironment and among its companions and that such behavior is directed 

 by the ruling instinct. We must observe, however, that a duck learns not 

 only by its own experiences, but also from the experienced actions of social 

 companions. A captive duck living in isolation learns the objects to be eaten 

 and those to be avoided quite independently. It learns its position within 

 its environment so that it moves to its feeding tray, water tank, or brooder 

 when hungry, thirsty, or cold. It may reach adulthood, learning which ob- 



• For a discussion of learning in birds and a recent bibliography on the subject, the reader 

 is urged to read Thorpe, 1951b. 



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