Brood Sizes of Sympatric American Black Ducks and Mallards in Maine

摘要: The long-term decline of the American black duck (Anas rubripes) population has been attributed to lower productivity ducks that might have excluded from fertile agricultural wetlands by mallards platyrhynchos). We monitored broods on 53 in 1993 and 58 1994 determine mean brood sizes forested landscapes. Study were moderately highly fertile. 94 each year 46 (1993) 52 (1994) mallard until they reached Class IIC-III (near fledging). No differences existed (P = 0.71) size between (1993: 3.95 ± 0.23; 1994: 4.59 0.24) 3.96 0.35; 5.00 0.43) either year. Brood for species, however, was different years 0.014) among wetland sites 0.001). Mean larger < 0.05) 2 large impoundment complexes (Lake Josephine Lake Christina) compared with other or ≥ 0.41) IIc-III mallards, whether species alone together wetlands. Our data document is similar where breed sympatrically Maine.