BREEDING BIOLOGY OF THE LEAST BITTERN

THE Least Bittern (Ixobrychus exilis) is one of the most inconspicuous of all marsh birds. It is neither shy nor rare within its range but is merely a quiet bird which lives out of sight among marsh emergents. Observations on the species have been numerous but brief, and no detailed study of any phase of its breeding biology has been published. However, considerable data have been reported on the closely related Little Bittern (I. minutus) of Eurasia. The data presented here were obtained during 1958-1960 at Goose and Little Wall lakes near Jewell, Iowa, and at Trumbull and Rush lakes near Ruthven, Iowa. Information was collected during marsh investigations sponsored by the Iowa State University Alumni Research Foundation and the National Science Foundation Teacher Research Participation Program. I am indebted to Cecil E. Spatcher and Robert A. Buckley for field assistance, to Drs. Andrew J. Meyerriecks and Ralph S. Palmer for assistance with literature, and to Dr. Meyerriecks for comments on the manuscript. Dr. Thomas Kent and Fred Kent of Iowa City, Iowa, permitted use of unpublished data.