Taxonomy/Description

Red-breasted Mergansers are in the order Anseriformes and family Anatidae. By order, they are grouped together with waterfowl and by family they are grouped together with ducks and swans. Red-breasted Mergansers are 23inches (58cm) in size. They are medium-sized with "saw-bills". They are also dichromatic which means that males and females are different in appearance. Male Red-breasted Mergansers have greenish-black heads with white necks. They have a reddish breast with dark streaks that are bordered on both sides by a black-and-white patch. They have a black back and a white belly with white secondary coverts. Female Red-breasted Mergansers have a red-brown head that is paler on the throat, but do not have a well defined chin. Their red-brown head fades to a pale breast. They have a gray and white breast and belly with brown body plumage.

Habitat/Diet

Red-breasted Mergansers prefer habitats of tundra and boreal forests on fresh, brackish and saltwater wetlands. They prefer sheltered bays that are not far from the sea coast. They choose their habitat based on the abundance of small fish. Red-breasted Mergansers are found breeding in Alaska, northern British Columbia, northern Alberta and all eastern provinces of Canada. In the United States, they are found breeding in northern Michigan, Minnesota, Wisconsin and Maine. Red-breasted Mergansers can be founding wintering along the Pacific Coast, Atlantic Coast and in the Great Lakes.

Red-breasted Mergansers eat small fish (10-15cm) and crustaceans. Some times they will eat worms, insects and amphibians. They forage by floating and then diving. They use their feet and/or wings for propulsion. Red-breasted Mergansers are known to forage in cooperative manner which drives fish into shallow manner.

Behavior/Reproduction

Red-breasted Mergansers have a monogamous mating season and one brood per year. They nest close together and can often be considered colonial nesters. They do not breed until after their second year. Females are in charge of building the nest which is sheltered, usually under low vegetation. It is usually within 25feet of water. The female will lay 8-10 olive buff eggs that she will incubate for the 29-35 day incubation period. The male will disappear after incubation begins. The young are precocial which means they are downy, mobile and able to find food. The female will care for the young until they are ready to fledge which occurs 59-64 days after hatching.  Many times several broods will combine and be cared for by one or many females.

Where to see them in WNY  

Red-breasted Mergansers are common on the Niagara River and at the Iroquois National Wildlife Preserve.