Red-Breasted Merganser Overview
The red-breasted merganser is a diving duck that can live around rivers, lakes and ocean waters, though it prefers saltwater. In Hawaii, it is best treated as a rare visitor rather than an everyday duck. Its long, thin bill helps separate it from many familiar pond ducks, giving the bird a sharper, more streamlined look.
Adult males have a dark head with a green shimmer, a white neck, a rusty-colored breast, a black back and white underparts. Adult females look softer, with a rusty-colored head and a gray body. These markings can help birdwatchers tell them apart from similar diving ducks.
Diving, Food and Flight
Red-breasted mergansers dive underwater to find food. Their diet includes small fish, crustaceans, frogs and aquatic insects. Because they hunt by diving, they are more likely to be associated with open water than shallow wetland birds that feed along mudflats or pond edges.
This species is also often mentioned for its fast flight. Some accounts have claimed the red-breasted merganser can reach about 100 mph in level flight, though that claim is disputed because the white-throated needletail may be faster. For similar uncommon waterfowl in the Hawaii bird guide, compare the common merganser, hooded merganser, common goldeneye and long-tailed duck.
