A Study of Nesting Wood Ducks in Iowa

This article concerns the nesting habits of the Wood Duck (Aix sponsa), including nest site selection, egg laying, incubation, hatching, departure from the nest, and travel of the brood to water.The material is taken from notes covering over 2.500 nesting box checks plus many hours of watching from a portable blind or other vantage point, in the course of 12 years, beginning in 1939.At that time the Illinois Natural History Survey furnished 50 Wood Duck boxes to the Crystal Lake Club near Burlington, Iowa, on the Mississippi River bottoms.For four years I helped make semiannual inspections of these boxes.Ducks used only a small percentage and few were successful due to predation by raccoons and other animals.In 1943 three boxes were moved to my yard, where a single pair of Wood Ducks had been seen prospecting for a nesting site.To my surprise and delight, each of the three boxes was used by the ducks and successful hatches resulted in each case.Subsequently, the project at my home was expanded by hanging additional boxes.In recent years the nesting colony has grown to include 10 to 12 pairs, as shown in tab!e 1.Table 1 The Growth of the Nesting Colony from 1943 to 1950 Year Number of nests Number of available nest sites