The Duck Factory 



Water, vegetation, and sky are only part of the autumn marsh. It is the birds tliat give it life. 

 Prairie potholes of the North Central United States and South Central Canada raise slightly more 

 tlian half of tlie continent's ducks. Both shallow and deei)er water areas are needed on the In-eeding 

 grounds. Adults use the small temporary water areas for resting spots, courtship, and nesting sites. 

 When these areas go dry the deeper ponds raise the l)roods. A shortage of one tyjie reduces tlie \alue 

 of the otliers. 



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f..9. Koil Coti!<erLation Ifrrvier 



Other duck breeding grounds tluougliout the rnited States are widespread and varied. Indi- 

 vidualh-, few are impressive. Together, they raise tlie lliglits of waterfowl that give tiie autunui marsh 

 life — and value. 



