Lophodytes cucullatus

A medium-sized (16-19 inches) duck, the male Hooded Merganser is most easily identified by its black head and body, rufous flanks, thin bill, and conspicuous white crest. Females are duller brownish-gray overall with a smaller brown crest. At a distance, the male of this species may be confused with the male Bufflehead (Bucephala albeola), which may be distinguished by its greenish head and white body. Duck hunters often call mergansers “saw-bills” in reference to their long, thin, serrated bills. The Hooded Merganser breeds across a large part of the eastern United States and southern Canada south to the Gulf coast and west to the edge of the Great Plains. Another breeding population exists in the Pacific Northwest. In winter, this species migrates away from northern and higher-altitude areas, and may be found along the Pacific coast from Alaska to California, in the eastern and southeastern U.S., and at scattered locations in the western U.S.Hooded Mergansers breed in lakes and ponds surrounded by woodland. Like a couple other smaller species of ducks, this species nests in tree cavities, often those left over from woodpecker nest sites. In winter, Hooded Mergansers may be found in freshwater or saltwater on rivers, marshes, estuaries, and bays. This species primarily eats small aquatic animals such as crustaceans, fish, and insects. One of several species of “diving ducks” in North America, Hooded Mergansers may be observed submerging themselves to feed in the water or on the bottom. In winter, they may also be observed in small flocks on slow-moving bodies of water. Like other mergansers, the Hooded Merganser undertakes swift, straight flights between bodies of water or on migration. This species is primarily active during the day.

Threat Status: Least concern

Breeds n North America; winters to Mexico and West Indies.

Gulf of Maine, Gulf of Mexico, North West Atlantic, Portuguese Exclusive Economic Zone, Spanish Exclusive Economic Zone, United Kingdom Exclusive Economic Zone

North America; Bay of Fundy to Northern Florida

The Hooded Merganser breeds throughout the Pacific Northwest of the United States, across southern Canada, and east of the Mississippi. It is largely concentrated in forested regions around the Great Lakes. Wintering ranges include an area along the Pacific Coast of California, and a second area of coastal habitats from Delaware through Texas.

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Breeding

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDS: southeastern Alaska, central British Columbia, and southwestern Alberta south to southwestern Oregon, central Idaho, and northwestern Montana; and from central Saskatchewan to Nova Scotia, south to southeastern Kansas, northern Louisiana, northern Georgia, and (rarely) Florida. WINTERS: along Pacific, Atlantic, and Gulf slopes, mainly from southeastern Alaska to northern Baja California, and New England to Florida and west to northern Mexico, irregularly in the interior of southern Canada and the U.S., and in the northern Bahamas and Greater Antilles (AOU 1983); rare in Hawaii.

At 40-49 cm, the Hooded Merganser is the smallest North American merganser. Exact weights have not been documented. Like all mergansers, it has a long, narrow, serrated bill. It has a brownish-black back and wings, with a white underside. The male has a black head with a white, fan-shaped crest, which is bordered in black. The males iris is bright yellow, while the iris of females and immature males is duller brown.

Range mass: 540 to 680 g.

Range length: 40 to 49 cm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: sexes colored or patterned differently; male more colorful

Length: 46 cm

Weight: 680 grams

Differs from other mergansers in being smaller, having white head patches (males), and by lacking a red bill. Differs from the bufflehead in lacking white sides.

forested wetlands, freshwater and brackish bays, estuaries, and tidal creeks and ponds

Systems

• Terrestrial
• Freshwater
• Marine

The Hooded Merganser nests in forested wetlands throughout its range. Some records show nesting in man-made boxes on grasslands and in nonforested wetlands. The kind of forest used for nesting varies from spruce/fur to cottonwood/elder and oak/cypress/tupelo, depending on the geographic location. In the winter they seek out shallow, freshwater and brackish bays, estuaries, and tidal creeks and ponds.

Habitat Regions: temperate ; terrestrial ; freshwater

Terrestrial Biomes: forest

Aquatic Biomes: lakes and ponds; rivers and streams

Wetlands: marsh ; swamp

Other Habitat Features: riparian

Depth range based on 6 specimens in 1 taxon.

Environmental ranges
  Depth range (m): 0 - 0
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Comments: Streams, lakes, swamps, marshes, and estuaries; winters mostly in freshwater but also regularly in estuaries and sheltered bays (AOU 1983).

Nests usually in tree cavities in forested regions near water, often near fast-flowing streams (AOU 1983), also forest ponds and lakes, flooded forest, riverside swamps. See Zicus (1990) for information on successful use of nest boxes in Minnesota.

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

In the east, northward migration occurs mainly in February-May. Returns to breeding areas in west mostly in late March-April. In the east, southward migration occurs mostly in September-December. Most movement to wintering areas occurs in November in the west.

Hooded Mergansers feed in clear aquatic habitats, such as forested ponds, rivers, streams, and flooded forests. Their primary foods include aquatic insects, fish, and crustaceans.

Animal Foods: fish; insects; aquatic crustaceans

Primary Diet: carnivore (Piscivore , Insectivore , Eats non-insect arthropods)

Comments: Eats mostly small fishes, crayfishes and other crustaceans, and aquatic insects obtained by diving underwater (Palmer 1976).

Lophodytes cucullatus (Fish and crustacean eating birds) preys on:
Pagurus
Pagurus maclaughlinae
Pinixia floridana
Neopanope texana
Processa bermudiensis
Penaeus duoarum
Palaemonetes floridanus
Urophycis floridana
Prionotus scitulus
Prionotus tribulus
Anchoa mitchilli
Menidia beryllina
Gobiosoma robustum
Microgobius gulosus
Lagodon rhomboides
Leiostomus xanthurus
Laridae
Cyprinodon variegatus
Anatidae
Fundulus confluentus
Fundulus similis
Adinia xenica

Based on studies in:
USA: Florida (Estuarine)

This list may not be complete but is based on published studies.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

100,000 to >1,000,000 individuals

Average lifespan
Status: wild: 138 months.

Maximum longevity: 11.5 years (wild)

Pair formation has been observed from November through January. Only monogamous pairs have been documented.

Mating System: monogamous

Females select the nest site, which is usually a cavity in a dead or live tree. Nest boxes, along with already built and abandoned nest sites, are preferred. Cavities are usually 4-15 feet off the ground. Between 7 and 15 eggs are laid shortly after the nest is completed, from late February through early June, depending on latitude, although most breeding occurs in March and April. Incubation begins after all the eggs have been laid. The male abandons the female shortly after this point. The female incubates for nearly one month, during which time she loses 8-16% of her body weight. After the ducklings hatch they usually leave the nest within about 24 hours.

Breeding interval: Hooded mergansers have one brood each year.

Breeding season: Hooded mergansers breed from late February into June, depending on latitude. Although most breeding occurs in March and April.

Range eggs per season: 7 to 15.

Range time to hatching: 26 to 41 days.

Average time to independence: 5 weeks.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate)

Average eggs per season: 11.

Females brood eggs in the nest and care for young after hatching. Males leave the female soon after egg incubation begins. Young hooded mergansers leave their nest within 24 hours of hatching and are able to feed and dive immediately upon emergence from the nest. There is little information on parental care after hatching. One female abandoned her brood 5 weeks after hatching.

Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female)

Clutch size is 6-18 (some nests may include eggs of wood duck or goldeneye in some areas). Incubation lasts 29-37 days, by female. Young first fly at estimated age of 10 weeks. First breeds at about 2 years (Terres 1980, Palmer 1976). Nesting is dispersed; in Minnesota, installation of nest boxes produced a nesting density of about 0.4 nests per sq km (Zicus 1990).

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 9
Specimens with Barcodes: 14
Species With Barcodes: 1

The following is a representative barcode sequence, the centroid of all available sequences for this species.

There are 9 barcode sequences available from BOLD and GenBank.  Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

Download FASTA File

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Justification

History

• 2008
  Least Concern
• 2004
  Least Concern

At the turn of the century, Hooded Mergansers were largely overhunted. Today, however, they are not a prized sport species. Habitat degradation is now a more pressing concern for their conservation. River channalization, deforestation, and agricultural practices have caused an increase in loose sediment and turbidity, reducing the available habitat for the Hooded Merganser. Also, acid rain has the potential to harm the species, because a low pH can cause a significant reduction in aquatic invertebrates. A diminished food supply would reduce the growth of young ducklings. There is no informaton on the exact population size, and the Hooded Merganser has no special conservation status. In the future, care must be taken to preserve the cavity producing trees and forests which these birds depend on.

US Migratory Bird Act: protected

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

Canada

Rounded National Status Rank: N5B - Secure

United States

Rounded National Status Rank: N5B,N5N : N5B: Secure - Breeding, N5N: Secure - Nonbreeding

Rounded Global Status Rank: G5 - Secure

Reasons: Secure due primarily to large range; uncommon.

Comments: Vulnerable to forestry practices that limit or eliminate potential nesting sites.

There are no known adverse effects of hooded mergansers on humans.

Hooded Mergansers are still hunted occasionally for sport. Aprooximately 18, 000 are harvested annually in the U.S. and Canada combined. They are also used for various scientific studies in the wild, because they will nest in artifical nestboxes.

Positive Impacts: body parts are source of valuable material; research and education