Waterfowl Nesting Island Development

An ecological study of nesting waterfowl was conducted on two islands and a peninsula in Miquelon Lake, Alberta. In addition to observations of population parameters, aided through a study of nesting waterfowl, experimentation through habitat manipulation was conducted to test hypotheses concerning the roles of predation on, and habitat selection by, waterfowl. The species studied included lesser scaup (Aythya affinis), gadwall (Anas strepera), mallard (Anas platyrhynchos), pintail (Anas acuta), white-winged scoter (Melanitta deglandi), and American widgeon (Mareca americana). Evidence indicates that waterfowl concentrate on islands to nest in response to their insular position which excludes many mammalian predators. Distribution of vegetation on the islands affected the distribution and density of waterfowl nests. The presence of gulls neither attracted nor repelled waterfowl from nesting on the islands. The numbers of gulls, which influenced the development of vegetation, indirectl.

The ure of artificially constructed islands for nesting waterfowl has recently gained attention as a management technique for increasing local populations on the northern prairies which are otherwise declining.However, little quantitative information is available indicating which design features of these islands might best enable them to achieve their full potential. Waterfowl nesting on one natural and 21 artificial islands located in Pool 326 of the J. Clark Salyer National Wildlife Refuge (NWR) in North Dakota were studied from 1982-1983. A total of 286 duck nests of seven species were located, with gadwall (Anas strepara),mallard (A. platyrhynchos), and blue-winged teal (A. discors)representing over 90% of all nests discovered. Mean annual waterfowl densities were 8.7 nests/ha with an average Mayfield corrected hatching success of 24%, resulting in an annual duckling production of 27 birds/ha. Several physical and vegetative characteristics of these islands were quantified in o.