Effects of Stream Channelization on Terrestrial Wildlife and Their Habitats in the Buena Vista Marsh, Wisconsin

Abstract

Stream channelization affected wildlife in the Buena Vista Marsh in Central Wisconsin by draining wetlands, setting back plant succession and decreasing habitat diversity along stream banks. Plant and animal species composition and abundance were studied in a continuum of plant successional stages from grassland to mature woods on stream banks adjacent to recently dredged (6 years), old dredged (50 years), and natural streams from July 1974 through June 1976. Sheet-water area and longevity, and wildlife use of three sheet-water areas with various degrees of drainage were compared in spring and summer. Bird and mammal species diversity and bird abundance increased as plant succession advanced, until a mature wooded stage was reached. Abundance of small mammals was related to the amount of ground cover and the diversity of habitats along the stream banks. Reptile and amphibian species diversity was greatest along natural and old dredged streams having partially submerged branches and low-lying, moist areas. Sheet-water area and longevity were greater on undrained wetlands than on wetlands adjacent to old dredged channels and were least near recently dredged stream channels. Waterfowl use, bird nesting, and reptile and amphibian abundance also were greatest on the undrained area. Invertebrates and various seeds made up 98.4 and 1.6 percent, respectively, of the diet of breeding blue-winged teal (Anas discors) using sheet-water.