L. Reichenbach, 1853
The hooded merganser (Lophodytes cucullatus) is a small duck and is the only member of the genus Lophodytes.
Hooded mergansers have a crest at the back of the head which can be expanded or contracted. In adult males, this crest has a large white patch, the head is black and the sides of the duck are reddish-brown. The adult female has a reddish crest, with much of the rest of the head and body a greyish-brown. The hooded merganser has a sawbill but is not classified as a typical merganser.
Hooded mergansers are the second smallest species of merganser, with only the smew of Europe and Asia being smaller, and is also the only merganser whose native habitat is restricted to North America.
A few of these ducks have occurred as vagrants to Europe; however, this attractive species is quite common in captivity, and most birds seen in the wild in Europe are presumed to be escapees.
A species of fossil duck from the Late Pleistocene of Vero Beach, Florida, was described as Querquedula floridana (a genus now included in Anas), but upon reexamination turned out to be a species closely related to the hooded merganser; it is now named Lophodytes floridanus, but the exact relationship between this bird and the modern species is unknown.
The hooded merganser is a sexually dimorphic species. The female has a brown body, with a white underside and a light brown crest extending from the back of the head. The male has a similar appearance during nonbreeding season (although his eyes are yellow while the female's are brown). During breeding season, however, the male's plumage changes color: The head, back and neck become black, with white stripes near the chest and tail, and the bird develops a white crest on the back of the head that can be extended to attract mates.
First-winter birds differ from adult females, in having a grey-brown neck and upper parts (black on adult females), and narrower white tertial-edges than adults; all females are dark-eyed whereas in first-winter males, a pale eye is acquired during the winter.
The hooded merganser is most often found in areas with ample amounts of emergent vegetation. The hooded merganser is known to occupy smaller bodies of water such as ponds and small estuarine environments. The hooded merganser is also found in larger wetlands, impoundments, flooded timber, and rivers. Hooded mergansers prefer fresh water but will inhabit brackish water sites.
The diet of this small diving duck is typically aquatic insects, fish and aquatic invertebrates. Most studies conducted on their diet show that 44-81% is fish, 22-50% crayfish (aquatic invertebrates), and 13-20% aquatic insects. Prey is typically found by sight while diving underwater. 
Males and females of this species form monogamous pairs and remain together until the female successfully lays her eggs. Breeding occurs anytime between the end of February through June but is dependent upon region. At this time the male leaves the female to incubate and care for their brood. Females will actively seek out cavities in dead trees or artificial nest boxes like those frequently occupied by wood ducks. Cavity selection is generally a site that is 4-15 feet off the ground.
Females will lay a clutch size of 7-15 eggs and begin incubation when the last egg has been laid, indicating a synchronous hatching event. During incubation, the female may lose anywhere from 8% to 16% if her body weight. This will result in all hatchlings being the same size and easier parental care for the female.
Hooded merganser hatchlings are precocial like most waterfowl and will usually leave the nest within 24 hours after they hatch. Once they leave, the young will be fully capable of diving and foraging on their own.
Hooded mergansers have two year-round ranges. One is located in the Eastern United States. It goes from the Gulf Coast to the around the Canadian border and from the Atlantic Coast to around the Mississippi. A smaller year-round range is located in Washington, southern British Columbia, and northern Idaho. The species also breeds from Missouri to southern Canada and from Nova Scotia to eastern North Dakota and Saskatchewan.
Vagrancy to Europe
Although hooded merganser is a common species in captivity in Europe and most recorded in the wild are regarded as escapes, a small number of birds have been regarded as genuine wild vagrants. Britain's current first accepted record is a bird which was seen on North Uist in October 2000. Small numbers are seen regularly in Dublin, but these are presumed to be escapees.
Management and conservation
Population declines in the past have been linked with large scale deforestation. Because these waterfowl are cavity nesters, they require more mature trees in which suitable nests are likely to be found. Proper timber management today is thought to be increasing available habitat. When managing wooded habitat for cavity nesting ducks, sufficient mature trees should a priority consideration.
These ducks do benefit from artificial nest boxes. Nest boxes should be implemented if natural habitat is lacking.
Acid rain and other types of pollution such as run off maybe affecting hooded mergansers as well due their high reliance on aquatic forage.
- BirdLife International (2012). "Lophodytes cucullatus". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
- "Hooded Merganser Fact Sheet, Lincoln Park Zoo"
- Vinicombe, Keith (2002) Time for a rethink Birdwatch 119:16-7
- Dugger, B. D., K. M. Dugger and L. H. Fredrickson. 2009. Hooded Merganser (Lophodytes cucullatus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu.prox.lib.ncsu.edu/bna/species/098
- Rabbitss, Brian (2009) Hooded Merganser on North Uist: a return to the British List British Birds 102(3): 122-9
- Heusmann, H. W. and T. Early. 1988. A comparison of wooden boxes and plastic buckets as waterfowl nest structures. Wildl. Soc. Bull. 16:45-48.
|Wikimedia Commons has media related to Hooded Merganser.|
|Wikispecies has information related to: Lophodytes cucullatus|
- Hooded Merganser Species Account – Cornell Lab of Ornithology
- Hooded Merganser - Lophodytes cucullatus - USGS Patuxent Bird Identification InfoCenter
- eNature.com: Hooded Merganser
- Massachusetts Breeding Bird Atlas - Hooded Merganser
- Hooded Merganser videos, photos, and sounds at the Internet Bird Collection
- Hooded Merganser photo gallery at VIREO (Drexel University)