Northern Prairie Wildlife Research Center
Robert D. Hoffman
Duck's Unlimited, Inc.
Bismarck, ND 58501
The size and number of islands constructed is determined based on habitat characteristics and historical waterfowl production records. Islands are constructed in wetlands at a minimum distance of 100 yards from the nearest shoreline and 65 yards apart, and in locations with the greatest erosion protection. Islands created by separating a peninsula from the mainland involves either excavating a 3-foot deep, 100-yard wide canal, or constructing an electric predator-proof fence. Excavated peninsulas provide natural erosion protection and little disturbance to existing upland vegetation. Electric fences, although less expensive, have a higher maintenance requirement. A limited number of electric predator-proof exclosures have been constructed on uplands. Results from current studies by the U.S. Fish and Wildlife Service will determine DU's interest in future construction of exclosures. Artificial nesting structures have been constructed to enhance mallard (Anas platyrhynchos) and Dusky Canada Geese (Branta c. occidentalis) production in Minnesota and Alaska, respectively.