Wildlife Damage Management, Internet Center for


Date of this Version



Proceedings Ninth Bird Control Seminar, Bowling Green State University, Bowling Green, Ohio, October 4-6, 1983. Ed. William B. Jackson and Beth Jackson Dodd


Copyright (c) 1983 Hans Blokpoel and Gaston D. Tessier


During the 1983 breeding season experiments were carried out at a large colony of ring·billed gulls (Larus delawarensis) at the Eastern Headland of the Toronto Outer Harbour. At the beginning of the nesting season several 20 x 20 m plots were established in areas where gulls were starting to nest. The plots were covered by parallel monofilament lines with a spacing of 60 cm. The lines were installed at either 60 cm (Low Exclosures) or 120 cm (High Exclosures) above the ground. The lines were highly effective in preventing gulls from nesting in all experimental plots. On average there were 3.0, 3.8, and 224 nests in the High Exclosures, Low Exclosures and Control Plots, respectively. Advantages and disadvantages of the method are discussed.