Habitat preferences of breeding black ducks (Anas rubripes Brewster) in Nova Scotia

Investigations were conducted at twenty-two fresh water wetlands in western Nova Scotia between April 1969 and August 1970. The objective was to determine major breeding habitat preferences of the black duck (Anas rubripes) by comparing biotic and abiotic features with the behavioral ecology of breeding pairs. Black duck breeding habitat contained concentrations of available food. Territorialism was found to be a component of black duck reproductive nature in which selective advantage appeared to be the monopoly of food. A distinction is made between waiting areas occurring within and beyond the breeding territory. The density of breeding pairs per wetland is attributed to the extent and distribution of food concentrations relative to the presence or absence, distribution and effectiveness of visual barriers in relation to the size and configuration of the wetland. Breeding habitat appeared to be occupied to capacity, and it is suggested that late ice-out may diminish the adequacy of small grouped wetlands where the home ranges of pairs overlap. No correlation was found between the water characteristics measured and black duck breeding habitat.