Factors affecting nest success in the Mallard and Tufted Duck.
Factors affecting nest success in the Mallard and Tufted duck were studied at one site in 1980 and two sites in 1981 in North Buckinghamshire. Carrion Crows, Magpies and rats were the main predators of clutches, destroying them mainly during the laying period. The proportion of Mallard nests destroyed by predators increased as the minimum height of vegetation around the nest declined. Nests of both species were more successful on islands than those on the mainland and island nests were located in taller vegetation. Generally the closer a Tufted Duck nest was to another nest the greater was the risk of predation. In 1981 nests of both species at one site suffered heavier clutch predation than those at the other and were located in significantly shorter vegetation and were closer together. Tufted Duck nests were more successful than those of Mallard, they bred approximately five weeks later, taking advantage of taller vegetation which was conducive to high nest success.