Bird use of wetlands subjected to cattail (Typha spp.) control was examined at Horicon marsh in Wisconsin from 1973 to 1976. Birds were counted along a 2-km route during April and May of each year. Nest searches were conducted once a year from mid-May to mid-June. Several different cattail control methods were conducted on different plots; control methods included mechanical crushing, herbicide (Amitrol T, Radapon, or Dowpon) application, scraping, and burning. Control methods were applied after the water in wetlands had been drawn down. Application rates for Amitrol T and Radapon ranged from 3.85 kg/ha to 34 kg/ha. Application rates for Dowpon ranged from 5.6-10 kg/ha. A John Deere 450 crawler-tractor with a bucket was used to scrape away residual cattail and 5-10 cm of the bog mat. Openings created by herbicide application were used by breeding duck pairs, coots, and by feeding herons and egrets. The dead residual cover that remained after spraying contained higher densities of blackbirds, Marsh Wrens, rails, and coots than were found in the surrounding wetland. The burned areas were used by migrating Canada Geese and as feeding sites by herons and egrets. In the scraped area, mounds of dead debris were present in the openings and the authors suggested that Canada Geese had nested on these mounds. –American Coot. 69% of 505 nests were in cattail, 13% were in bur- reed (Sparganium eurycarpum), 8% in sedges (Carex spp.), 7% in shrubs, 1% in softstem bulrush (Schoenoplectus tabernaemontani), and 2% in other; used vegetation types according to availability. Twenty-five coot nests were found in or near crushed plots or plots sprayed with herbicide. Six nests were within the crushed plots, 10 were within 6 m of an opening created by crushing or spraying, and 4 were >6 m from an opening created by crushing or spraying. In July, coots with young were observed in the open water created by scraping. –Sora. 44% of 27 nests were in cattail, 11% in bur-reed, and 44% in sedges. Selected sedge habitat more than expected based on availability. Nested in the dead debris adjacent to the sprayed area. –Least Bittern. 95% of 21 nests were in cattail and 5% were in softstem bulrush. Nest platforms were interwoven and supported by cattail stems. Nests were located >0.3 m above the water’s surface. One Least Bittern pair nested on a crushed plot. –Virginia Rail. 30% of 10 nests were in cattail, 10% in bur-reed, 30% in sedges, 10% in softstem bulrush, and 20% in other. Selected sedge habitat more than expected based on availability. Nested in the dead debris adjacent to the sprayed area. –American Bittern. 100% of three nests were in cattail. –King Rail. Only one nest was found in softstem bulrush. Nested in the dead debris adjacent to the sprayed area. –Black Terns. Nested in groups of 3-5 pairs in open areas where floating debris was abundant. Nests were not associated with green plants. –Pied-billed Grebe. Nested in open areas and were not associated with green plants. –Marsh Wren. Preferred to nest in living, green cattail that were adjacent to sprayed areas. Sixteen nests were found in live cattail stands and one nest was located in dead cattail. Management suggestions: –Recommendations for cattail control were given for three water depth zones: deep water (herbicides, cutting stems below the water’s surface); intermediate water depth (cutting stems below the water or on ice, crushing); and shallow water (crushing, applying herbicides). Cutting stems underwater stops the flow of air to the roots. Ice cutting involved cutting cattail stems on ice and then flooding the wetland in the spring so that the stubble was covered with water.
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