Ricefields and fulvous wistling ducks in Senegal.

It has long been known that Fulvous Whistling Duck Dendrocygna bicolor has significantly benefited from the extension of rice fields throughout the wo rld. Nevertheless, this Link is not so much with the size of areas growing rice as with the poorly grown plots. The present study shows a fairly good correlation between the estimated size of poorly managed ricefields and the important numerical variations of Fulvous Whistling Duck populations in Se negal. We also discuss the eventual effect on the validity of this conclusi on of bias that may have been introduced by the subjective criterion of est imated poorly managed rife acids and also by mixing censuses done by differ ent observers, nor always on the same areas and using different census tech niques.