Habitat Use and Movements of American Black Ducks in Winter

Abstract

We determined habitat use and movement patterns of 22 female American black ducks (Anas rubripes) wintering at Chincoteague National Wildlife Refuge (NWR), Virginia, with radio telemetry and aerial survey techniques during 15 December 1985-28 February 1986. Proportional use of saltmarsh, impoundment, and natural pool habitats was greater (P 1. Habitat use was affected by the day-night cycle and a tide-ice interaction. J. WILDL. MANAGE. 53(2):390-400 American black duck populations wintering along the Atlantic Flyway have declined almost 50% since 1954 (Steiner 1984). Excessive harvest (Geis et al. 1971, Blandin 1982, Grandy 1983), acid rain (Hansen 1987), and hybridization with mallards (Anas platyrhynchos) (Heusmann 1974, Ankney et al. 1987) have been suggested as factors responsible for this decline. Others believe that loss and degradation of wintering habitat may be affecting black duck populations, although the evidence is somewhat con-