Nesting of the Ruddy Duck in Iowa

THE Ruddy Duck (Erismatura jamaicensis rubida), though often elusive and secretive to the hunter and of late years relatively scarce in hunting bags, affords a great deal of pleasure to the Nature lover who seeks the bird in its native haunts. Aside from its esthetic value, a knowledge of the Ruddy Duck's habits during the critical period of reproduction is essential to the conservationist who would wisely perpetuate and increase this game bird. The nesting habits and habitat requirements of the Ruddy Duck were investigated as part of the waterfowl-research program of the Iowa Cooperative Wildlife Research Unit. The results of the research conducted in northwestern Iowa during the 1938, 1939 and 1940 seasons are here presented. Acknowledgments are made to Dr. George 0. Hendrickson, Zoology Department, Iowa State College, and to Mr. Thomas G. Scott, U. S. Fish and Wildlife Service, for suggestions and supervision of this work. An area with an abundance of natural lakes and marshes extending from two to three miles on either side of the Clay and Palo Alto County line was chosen for intensive observations. Within a radius of five miles of the city of Ruthven lie six lakes and numerous marshes constituting the largest single remnant of duck-breeding habitat in Iowa. The lakes, in common with other lakes scattered throughout northern Iowa, are the result of the relatively late Wisconsin glaciation which extended from the north-central part of the State as far south as Des Moines. Glacial debris in the form of morainic hills surrounds the lakes in the southern part but gives way to a high rolling plain in the northern part of the area. Approximately 53 square miles were included although only the 6000 acres of lakes, marshes and sloughs were of particular interest. Lost Island Lake, the largest lake of the group, has a surface area of 1260 acres, while marshy spots as small as a quarter acre are numerous.