Breeding habitat selection and home range of radio-marked black ducks (Anas rubripes) in Maine

Abstract

Telemetry techniques were used to monitor the movements and habitat use of 13 female and 7 male black ducks ( Anas rubripes ) in an inland breeding region of south central Maine in 1977–1980. Black ducks preferred persistent emergent, broad-leaved deciduous forested, and broad-leaved deciduous scrub–shrub wetlands over unconsolidated organic bottom, needle-leaved evergreen forested, and broad-leaved evergreen scrub–shrub ponds. Birds also made frequent use of small ephemeral pools and streams throughout the breeding period. Nests were located in several habitats ranging from wetland sites to upland areas 1.5 km from the most frequently used pond. Home range size averaged 119 ha for females and 231 ha for males and did not differ by reproductive stage. Three pairs used only a single pond during the incubation period. Home ranges were linear (linearity index = 2.8), averaging 1956 m long for females and 2755 m for males. Wetlands used most by hens during incubation recesses were not always those located closest to the nest. Radio-marked ducks that returned in subsequent breeding seasons demonstrated fidelity to the previously used home range. Pair bonds of marked birds lasted until day 19 or 20 of incubation for initial nesting attempts.