Nesting of waterfowl on islands in Lake Audubon, North Dakota

Nesting waterfowl were studied in 1978 and 1980 on 15 newly established islands with an area of 19 ha in 7,430-ha Lake Audubon in the Audubon National Wildlife Refuge (NWR), North Dakota. Islands ranged in size from 0.2 to 5.0 ha and were 60-1,600 m from the mainland. Cover available for nesting waterfowl was composed of grasses, legumes, and forbs with abundant residual plant material. In 1978 and 1980, 207 and 251 nests were found, respectively, of 10 waterfowl species primarily mallard (Anas platyrhynchos) and gadwall (A. strepera). Densities of waterfowl nests were 10.9/ha in 1978 and 13.2/ha in 1980. Nest success averaged 86% for the 2 years. Increased emphasis on construction of new islands and manipulation of plant communities on existing islands should be considered for waterfowl management programs in the prairie and parkland regions of North America.