Red-breasted MerganserMergus serrator

adult male, breeding
Glenn Bartley/VIREO
adult female
Rob Curtis/VIREO
adult male, breeding
Marvin R. Hyett, M.D./VIREO
adult male, breeding
Arthur Morris/VIREO

Description

A slim, crested, fish-eating duck, commonly seen around jetties and piers along the coast. Superficially this species is quite similar to the Common Merganser. However, the Red-breasted Merganser nests farther north, winters mostly on salt water, and nests mainly on the ground, while the Common winters mostly on fresh water and nests in cavities.

Habitat

Lakes, open water; in winter, coastal bays. During nesting season around lakes and rivers, within the northern forest and northward into tundra regions. In winter mostly on coastal waters, including bays, estuaries, and open ocean; a few winter on ice-free reservoirs and large rivers.

Feeding Diet

Mostly fish. Feeds mainly on small fish, also crustaceans, aquatic insects, and sometimes frogs, tadpoles, or worms. Young ducklings eat mostly insects.

Feeding Behavior

Forages by diving and swimming underwater. Sometimes a group appears to hunt cooperatively, several birds lining up and driving schools of small fish into very shallow water, where the mergansers scoop them up without diving.

Nesting

In courtship display, male stretches neck forward and upward, then suddenly dips neck and forepart of body underwater, with head angled up out of water and bill open wide. Nest: female selects site on ground, usually near water, in a spot sheltered by dense plant growth or debris. Sometimes nests inside hollow stump, under rock, or in shallow burrow. Nest is a simple depression, lined with down. Eggs: usually 7-10, sometimes 5-13. Olive-buff. Females sometimes lay eggs in each others' nests, occasionally in nests of other ducks. Incubation is by female only, 29-35 days. Young: Within a day after eggs hatch, female leads young to water, where they feed themselves. 2 or more broods may join, tended by 1 or more adult females, but young are left on their own within a few weeks. Young are capable of flight about 2 months after hatching.

Eggs

usually 7-10, sometimes 5-13. Olive-buff. Females sometimes lay eggs in each others' nests, occasionally in nests of other ducks. Incubation is by female only, 29-35 days. Young: Within a day after eggs hatch, female leads young to water, where they feed themselves. 2 or more broods may join, tended by 1 or more adult females, but young are left on their own within a few weeks. Young are capable of flight about 2 months after hatching.

Young

Within a day after eggs hatch, female leads young to water, where they feed themselves. 2 or more broods may join, tended by 1 or more adult females, but young are left on their own within a few weeks. Young are capable of flight about 2 months after hatching.

Conservation

Numbers are thought to be stable, but the species could be vulnerable because it forms such dense concentrations at certain times and places during migration, such as late fall on Lake Erie.

Range

May migrate later in spring and earlier in fall than the Common Merganser. Migrating flocks fly in V-formation or lines.

Listen

female flight
female quacks and male calls
soft croaks
male coursthip calls

Similar Species

adult male, breeding

Hooded Merganser

Mergansers are our only ducks that specialize in eating fish. The Hooded is the smallest of our three native merganser species, and often seems to be the least numerous, as it tends to live around swamps and wooded ponds where it may be overlooked. A cavity nester along wooded waterways in the temperate parts of North America, it has probably benefitted by taking advantage of nest boxes put out for Wood Ducks.

adult male, breeding

Common Merganser

This fish-eating duck is the typical merganser of freshwater lakes. Its flocks are usually small, but these may combine into big concentrations sometimes at large reservoirs. Common Mergansers living along rivers may spend hours resting on rocks or on shore. The British call this bird the "Goosander." In some parts of Europe, with artificial nesting sites provided, the species has become a common nesting bird along city waterfronts; this has not yet happened in North America.

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