The Hooded Merganser is unique among North American mergansers in that it breeds exclusively on this continent (Dugger et al. 1994). Throughout much of the eastern United States, populations of breeding Hooded Mergansers are widely dispersed in forested habitats consisting primarily of second growth timber. Few natural cavities occur for nesting waterfowl, and therefore, Hooded Mergansers commonly nest in artificial boxes. In areas where Wood Ducks are abundant and nest boxes occur in high densities, nest parasitism occurs at high levels (Semel et al. 1988). Consequently, female Hooded Mergansers have been observed incubating Wood Duck eggs (Zicus 1990), but no information exists relative to hatching success of parasitic eggs.