Seventy-five Years of Changes in Mallard - Black Duck Ratios in Eastern North America

Authors

Paul A. Johnsgard
Rose Disilvestro

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Recommended Citation

Johnsgard, Paul A. and Disilvestro, Rose (1976) "Seventy-five Years of Changes in Mallard - Black Duck Ratios in Eastern North America," American Birds: Vol. 30 : Iss. 5 , Article 2.
Available at: https://digitalcommons.usf.edu/american_birds/vol30/iss5/2