Habitat selection by dabbling ducks in the Baie Noire marsh, southwestern Quebec

Abstract

We monitored the waterfowl distribution in a recently flooded 260-ha marsh along the Ottawa River during 1974 and 1975. The birds (the three most important species were the black duck. Anas rubripes; the mallard, A. platyrhynchos; and the blue-winged teal, A. discors) did not distribute randomly among the five major habitats recognized, but clearly preferred a habitat dominated physiognomically by broken cattail (Typha angustifolia) cover but best characterized ecologically by ivy-leaved duckweed (Lemna trisulca), whitish water-milfoil (Myriophyllum exalbescens), and common bladderwort (Utricularia vulgaris). On average, broods (0.3/ha) and adult birds (6.6/ha) were four times more abundant per hectare there than in the next best habitat. This pattern of use was stable throughout the summer and throughout the daylight period as well. Multivariate analysis (correspondence factor analysis) enabled us to extract those ecological variables that played a determinant role in controlling plant distribution throughout the marsh. The observational and analytical techniques developed in this work could be applied to the development of marsh management plans designed to promote the expansion of the preferred waterfowl habitat.