Wood Duck Production and Management in Central Wisconsin

Abstract

First paper.-During 1982-84 most (63%) nest houses used by wood ducks at: Mead wildlife Area (MWA1 were Iocated in 2 relatively high-use areas. Wood duck nests could be distinguished from hooded merganser nests by measuring eggshell thickness. Natural cavities suitable for nesting wood ducks were present at a rate of 1/1.5 ha of hardwood forest. The observed low portion of nest-marked wood ducks in brood counts and trapping indicated that most of the production was not from nest houses. Low use of houses (9.9%) was not due to over-harvest of local wood ducks, as there was a high return of females to houses, and estimated kill rates were comparable to the statewide estimate. Second paper.-Six wood duck nest house designs at MWA were monitored during 1982-84. Of 759 houses inspected, wood ducks used 9.9%. Starling (Sturnus vulgaris), tree swallow (Iridoprocne bicolor), and hooded merganser (Mergus cucullatus) use was 46%l, 12.0%, and 10%, respectively. Wood ducks appeared to select more natural house designs; wood design had 16.5% use and Tom Tubbs had 14.8%. Hooded mergansers selected houses near open water with clear flight paths to the cavity entrance; wood-over-water design was selected at the highest (P<0.05) rate. Starling use was higher (P<0.05) in houses with deeper cavities and smaller diameters, and highest (P<0.05) in metal houses. Tree swallows selected larger houses with less depth, and use was highest (P<0.05) in bucket-over-water design. No spring use was recorded for 12.4% of the houses, and 3.7% were unusable annually. Winter nesting and roosting was common, with some houses (30-40%)_used by multiple wildlife species the same year. Third paper.-The estimated cost (housing only) to produce a flighted juvenile wood duck from MWA nest houses was $23.53 in 1984. The entire wood duck nest house program maintained by the Wisconsin Department of Natural Resources accommodated about 0.3-1.2% of the state's breeding wood ducks. Although nest house programs can benefit local populations, their importance in Wisconsin is declining and will probably continue to decline.