Winter movements of American black ducks in relation to natural and impounded wetlands in New Jersey

Radio telemetry was used to follow the movements and habitat use of female American Black ducks (Anas rubripes) trapped at Brigantine Division. Edwin B. Forsythe NWR (BNW) during three field seasons (1983-1896). Use of the BNWR impoundments was strongly associated with open vs. closed hunting seasons and with presence or absence of ice cover. Black ducks primarily used the impoundments for daytime roost sites and fed in saltmarsh areas at night during the hunting season. Following the hunting season use generally dispersed to saltmarsh and inland freshwater habitats. Freeze-up of the impoundments resulted in dispersal of black ducks to saltmarsh, inland freshwater, or areas to the south of New Jersey. We conclude that the BNWR impoundments only partially meet the habitat requirements of wintering black ducks. Access to saltmarsh habitats for feeding, and to inland freshwater habitats during periods of hard freeze, may be critical. The utility of the BNWR impoundments to black ducks, needs to be considered in conjunction with the availability of these other important habitats.