Our Beautiful World

Mergansers and Smew, fish-eating ducks  

Common Merganser, Mergus merganser
Red-breasted Merganser, Mergus serrator
Smew, Mergellus albellus
Hooded Merganser, Lophodytes cucullatus
Brazilian Merganser, Mergus octosetaceus
Scaly-sided Merganser, Mergus squamatus
Auckland Islands Merganser, Mergus australis

Common Merganser
© http://www.ecosystema.ru/

Family: Merginae

, Smew
Genus:Lophodytes, Hooded Merganser
Genus:Mergus, mergansers (5 living species, one extinct).

Genus Mergus
Mergus octosetaceus, Brazilian Merganser, No:
Mergus serrator, Red-breasted Merganser
, No: Siland
Mergus merganser, Common Merganser
, No: Laksand
Mergus squamatus, Scaly-sided Merganser, No: Skjellfiskand
Mergus australis Auckland Islands Merganser
, No: Aucklandfiskand
Genus Mergellus
Mergellus albellus, Smew, No: Lappfiskand
Genus Lophodytes
Lophodytes cucullatus, Hooded Merganser, No: Hjelmfiskand

Mergus is the genus of the typical mergansers, fish-eating ducks in the seaduck subfamily, Merginae.
The Hooded Merganser, often termed Mergus cucullatus, is not of this genus but closely related.
The other "aberrant" merganser, the Smew, Mergellus albellus, is phylogenetically closer to goldeneyes, Bucephala, but included here.

Although they are seaducks, most of the mergansers prefer riverine habitats, with only the Red-breasted Merganser being
common at sea. These large fish-eaters typically have black-and-white, brown and/or green hues in their plumage,
and most have shomewhat shaggy crests. All have serrated edges to their long and thin bills that help them grip their prey.
Along with the Smew and Hooded Merganser, they are therefore often known as "sawbills".
The goldeneyes, on the other hand, feed mainly on mollusks, and therefore have a more typical duck-bill.
They are also classified as "divers" because they go completely under-water in looking for food. In other traits, however,
the genera Mergus, Lophodytes, Mergellus, and Bucephala are very similar; uniquely among all Anseriformes, they do not
have notches at the hind margin of their sternum, but holes surrounded by bone.

Common Merganser, Mergus merganser, No: Laksand

The Goosander is distributed across the temperate and sub-arctic zones of the northern hemisphere.
It tends to breed further north and migrate southwards in the winter but some populations,
such as the British one, are largely sedentary.

The female, seenon photo above, has a greyish body and a reddish brown head and upper neck with a white chin.
Note the sharp border between the brown upper neck and the white lower neck which distinguishes the female
Goosander from the female Red-breasted Merganser.
Following the breeding season the male Goosander moults and looks very similar to the female during this process.

The male is mainly white and this can have a pinkish tinge in winter and early spring.
Its head looks black at a distance but is in fact a dark glossy green and it has a mane-like crest.
The bill is long, narrow and red with a black strip along the top.
It is also serrated to grip slippery fish and this gives rise to the designation of "sawbill".

They tend to be found in the upper reaches of rivers and on large inland lakes with plenty of trees in which to nest during the
breeding season but congregate in flocks during the winter and these can be at or near the coast.
However, when moulding in summer, the male can be found in great flocks, as in the picture above, from the mouth of the
River Tana in Finnmark, Northern Norway, where as many as 25.000 can be seen at that time.

© Arthur Grosset
Rather hungry fellow, this one....

It feeds primarily on fish obtained by diving from the surface using its legs for propulsion.
It normally returns to the surface to eat its prey clasping the fish round the middle
using its serrated bill then gradually moves the fish so that it can swallow it head first.

Picture of the week, March 27th, 2008. Photo taken near our home, Ulefoss, Norway

Red-breasted Merganser, Mergus serrator, No: Siland  

© http://www.ecosystema.ru/

© www.ecosystema.ru/

The Red-breasted Merganser male has blackish green head, white ring around its neck and redbrown breast.
The female has brown head and neck, and a white throat.

© www.ecosystema.ru/

The Red-breasted Merganser is good at diving, and has saw-tags on the edges of the bill,
which makes it easy to keep the fish it catches when diving.

© www.ecosystema.ru/

It is not uncommon to se The Red-breasted Merganser with up to 20 chickens or more.
Not because it is extra productive, but rather that the mother has met another couple,
then taken over her chicken, and now takes care of them all.

© www.ecosystema.ru/

The Red-breasted Merganser is normally wintering along the Norwegian coast,
where you may be lucky to view large flocks counting several thousand birds at once.

Denmark, January 2007
Photo © Jørgen Scheel

Myvatn, Iceland 2004
© www.vulkaner.no
Pictures from www.rusbiophoto.com: © www.ecosystema.ru/
All photos above if nothing else mentioned: © www.vulkaner.no

Smew, Mergellus albellus

© www.arthurgrosset.com

The Smew, Mergellus albellus, is a small duck, which is somewhat intermediate between the typical mergansers, genus Mergus,
and the goldeneyes, Bucephala. It is the only member of the genus Mergellus; sometimes included in Mergus, this genus is distinct
(though closely related) and might actually be a bit closer to the goldeneyes. The Smew has interbred with the Common
Goldeneye, Bucephala clangula.

The drake Smew, with its 'cracked ice' appearance, is unmistakable, and looks very black-and-white in flight. The females and
immature males are grey birds with chestnut foreheads and crowns, and can be confused at a distance with the Ruddy Duck;
they are often known as "redhead" Smew. It has oval white wing-patches in flight. The Smew's bill has a hooked tip and serrated
edges, which help it catch fish when it dives for them.

Male and female Smew.

This species breeds in the northern taiga of Europe and Asia. It needs trees for breeding. The Smew lives on fish-rich lakes and
slow rivers. As a migrant it leaves its breeding areas and winters on sheltered coasts or inland lakes of the Baltic Sea,
the Black Sea, northern Germany and the Low Countries, with small number reaching Great Britain (for example, at Dungeness),
mostly at regular sites. Vagrants have been recorded in North America. On lakes it prefers areas around the edges, often under
small trees.

The Smew breeds in May and lays 6–9 cream-colored eggs. It nests in tree holes, such as old woodpecker nests.
It is a shy bird and flushes easily when disturbed.

Hooded Merganser
, Lophodytes cucullatus

The Hooded Merganser, Lophodytes cucullatus, is a small duck and is the only member of the genus Lophodytes.
left:. http://en.wikipedia.org/wiki/File:Hooded_merganser_-_female.jpg
right:. http://en.wikipedia.org/wiki/File:Kappens%C3%A4ger_m%C3%A4nnlich_seitlich_050501.jpg

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.

Their preferred habitat for breeding is in swamps and wooded ponds of the northern half of the United States and southern Canada.
They prefer to nest in tree cavities near water, but will use Wood Duck nesting boxes if available and unoccupied. They form pairs
in early winter. The male leaves the female soon after she lays her eggs, leaving her responsible for all incubation. After hatching,
chicks leave the nest with their mother within 24 hours; they are already able to dive and feed themselves, although they remain
with their mother for another five weeks.

Hooded Mergansers are short-distance migrants, and winter in the United States wherever winter temperatures allow for ice-free conditions on ponds, lakes and rivers.

Female Hooded Merganser at Walsrode Bird Park, Germany.
The head is golden buff in the breeding season


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.

These ducks feed by diving and swimming under water to collect small fish, crustaceans and aquatic insects. They find their prey
underwater by sight.

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 upperparts (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.
Source: http://en.wikipedia.org/wiki/Hooded_Merganser

Brazilian Merganser, Mergus octosetaceus

Serra da Canastra, Minas Gerais, Brazil - April 2001
© Arthur Grosset

Red List Category & Criteria: CR C2a(i) ver 3.1 (2001)
Year Assessed: 2006. Assessor/s: BirdLife International
Evaluator/s: Butchart, S. & Pilgrim, J. (BirdLife International Red List Authority)
Justification: Recent records from Brazil, and particularly a recent northerly range extension, indicate that this species's status is better than previously thought. The remaining population is still extremely small and severely fragmented, and the perturbation and pollution of rivers continue to cause declines. For these reasons, it is listed as Critically Endangered.
History: 1988 - Threatened (Collar and Andrew 1988)
1994 - Critically Endangered (Collar, Crosby and Stattersfield 1994)
2000 - Critically Endangered (BirdLife International 2000)
2004 - Critically Endangered (BirdLife International 2004)
IUCN 2008. 2008 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 11 April 2008.

The Brazilian Merganser is one of the rarest birds in South America.
There may be less than 200 birds left.

One of the reasons for this scarcity are the strict habitat requirements
and the fact that suitable habitat is disappearing fast.

The Brazilian Merganser requires shallow, fast-flowing rivers with rapids and clear waters
in which it catches fish by diving. These have to flow through areas of forest, often surrounded by
cerrado, where the birds can build nests in tree cavities.


Photo:  © Carly Vynne

The Cerrado region of Brazil, comprising 21 percent of the country, is the most extensive
woodland-savanna in South America. With a pronounced dry season, it supports a unique
array of drought- and fire- adapted plant species and surprising numbers of endemic bird species. Large mammals such as the giant anteater, giant armadillo, jaguar and maned wolf also still
survive here but are competing with the rapid expansion of Brazil's agricultural frontier,
which focuses primarily on soy and corn. Ranching is another major threat to the region,
as it produces almost 40 million cattle a year.


The Brazilian Merganser is one of the duller members of its genus
(compare, for example, the Red-breasted Merganser, Mergus serrator).
It has a shiny dark green hood with a long crest, dark grey upperparts, a white wing speculum,
a pale grey breast and bright orange-red legs. In flight the white on the wings is very noticeable.

Serra da Canastra, Minas Gerais, Brazil - April 2001
© Arthur Grosset

These three birds are presumably a pair with a juvenile whose territory was on the Rio São Francisco just downstream from the Casca d'Anta waterfall.

Mirante com vista da Cachoeira Casca D'Anta e Rio São Francisco
Parque Nacional da Serra da Canastra

Each pair seems to require several kilometres of river as territory so one wonders
how the offspring manage to find new territories given the scarcity of habitat.

Serra da Canastra, Minas Gerais, Brazil - April 2001
© Arthur Grosset

Chapadão da Zagaia/Parque Nacional
2001/2002 - 81 individuals estimated in a survey around Parque Nacional da Serra da Canastra, Minas Gerais, Brazil
2002          - The first record for ten years is made in Argentina in the Uruzú river. Interviews with locals in Paraguay
                    indicate that the species may still exist there.
2007          - A new breeding site is found in Goiás state, Brazil.                                                                               
From the 'Rare Birds 2008' http://www.rarebirdsyearbook.com/

Scaly-sided Merganser, Mergus squamatus

Scaly-sided Merganser, male and female

The Scaly-sided Merganser or Chinese Merganser, Mergus squamatus, is an endangered typical merganser, genus Mergus.
It lives in temperate East Asia, breeding in the north and wintering in the south.

This striking sea duck has a thin red bill and a scaled dark pattern on the flanks and rump. Both sexes have a crest of wispy
elongated feathers, reaching almost to the shoulders in adult males and being fairly short in females and immatures. The adult male
has a black head and neck, white breast and underparts, and blackish mantle and wings, except for the white innerwings.
The scaling is also black, while the tail is medium grey. The female has a buffish head and otherwise replaces the male's black
with grey colour. The legs are orange-red and the irides dark brown in both sexes.

Their breeding habitat is rivers in primary forest in the southeastern Russian Far East, perhaps in North Korea, and in northeastern
China. The bulk of the species' population seems to breed in the Xiao Xingangling Mountains (Heilongjiang Province) and
Changbai Mountains of China. Mergus squamatus are migratory, wintering in central and southern China, with small numbers in
Japan, South Korea, Taiwan, northern Vietnam, Myanmar and Thailand. They arrive on the breeding grounds as soon as winter
is over, in March, and leave when the first cold nights come in late October.

This shy and easily startled bird favors mid-sized rivers which meander through wide expanses of mixed forest in the lowlands,
up to 1,000 meters ASL or less. Birds tend to move upriver during the day, both when startled and when foraging; the latter is
probably because stirred-up sediments will alert and hide prey downstream. Food is caught with the serrated beak from among
the riverbed gravel. Often the birds dive for prey, repeatedly submerging for a quarter-to half-minute with only a few seconds
pause between dives. In shallow water, the birds submerge only the head; they do not upend. The birds are not very social,
and only rarely encountered in groups larger than pairs or families. Even on the wintering grounds, groups of more than a dozen
are very rare.

ARKive video - Various stages of scaly-sided merganser chick development

Various stages of scaly-sided merganser chick development
Video: Peiqi Liu, peiqil@126.com
Audio: Granada Wild and BBC Natural History Unit

They spend most of the daylight time foraging, except around noon when they take some time to rest, preen and socialize at
the river banks, where they also sleep. The food of Mergus squamatus consists of aquatic arthropods and small or young fish.
Stonefly, Plecoptera, and Phryganeidae giant caddisfly larvae may constitute the bulk of its diet when available. Beetles and
crustaceans are eaten less regularly, though the latter may be more important in autumn. As aquatic insect larvae hatch in the course of the summer, fish become more prominent in the diet. Favorite fish species include the Dojo Loach, Misgurnus anguillicaudatus,
and the lenok Brachymystax lenok. More rarely eaten are such species as the lamprey Eudontomyzon morii, the sculpin
Mesocottus haitej, or the Arctic Grayling, Thymallus arcticus. Thus, they are opportunistic feeders; regarding fish, they will probably eat any species that has the correct elongated shape and small size.

Scaly-sided Mergansers nest in trees, as typical for the merganser and goldeneye lineage of sea ducks. Preferred nesting trees are
such species as Daimyo Oak, Quercus dentata, and Ussuri Poplar, Populus ussuriensis, a balsam poplar.

They are sympatric with Mandarin Ducks, Aix galericulata; though both relish the same insect larvae, they do not seem to
compete for food, but perhaps for nesting holes (which neither can excavate themselves). In its winter quarters, the Scaly-sided
Merganser might compete with other Merginae with which it shares its habitat then, e.g. Common Mergansers, Mergus merganser, and Common Goldeneyes, Bucephala clangula.

Red List Category & Criteria: Endangered C2a(ii) ver 3.1
Year Assessed: 2009. Assessor/s BirdLife International

This species has a very small population which is suspected to be undergoing a continuing and rapid decline as a result of habitat loss, illegal hunting and disturbance.
It is therefore listed as Endangered.

History: 2008 – Endangered
2007 – 2002 Endangered
2000 – Vulnerable
1994 – Vulnerable
1988 – Threatened

In the 1960s and 1970s, its decline in Russia coincided with economic development of the taiga. Primary forests in the valleys
of all large rivers were greatly altered, but large-scale deforestation in river valleys is now prohibited, however the new Russian
Forest Codex (2007) requires a water protection zone (no deforestation) of only 100 m for large rivers (50 m on each side),
and 50 m (25 m each side) for rivers shorter that 100 km, which is likely to significantly reduce suitable breeding habitat for the
merganser, which nests up to 150 m from the river. Logging of river sources and adjacent slopes has led to reduced spring water
levels and changes in fish abundance; since logging began on the Avvakumovka River in 2004 spring water levels and merganser
populations have undergone continuous declines.

Other major threats within the breeding range include illegal hunting, drowning in fishers' nets (a major cause of mortality at
Russian breeding sites in 2003-2007), disturbance from motor boats during the breeding season, river pollution and natural
predators. Increased hunting of waterfowl for sport together with poor regulation of the spring hunting season (which is intended
to coincide with passage migration and avoid targeting locally breeding birds) is a significant and increasing threat; large numbers
were reportedly shot in the Kievka River basin, southern Primorye, in spring 2008.

Threats in its Chinese breeding range include dam construction, deforestation, illegal hunting, human disturbance and the use of
poisons and/or explosives for fishing4. Fine meshed nets were a significant threat to the post-breeding congregations at Song
Jiang He in Jilin Province, China, but illegal fishing at the site has been reduced and only large meshed nets are used in legal fish-
farming. The site remains threatened by industrial pollution. The proposed Korean Grand Canal project, which aims to canalise
3,134 km of the Korean peninsula's river and would radically alter the Han and Nakdong rivers (which currently support an
estimated 30-50 birds in winter), was suspended in June 2008 but has not yet been cancelled.
BirdLife International 2009. Mergus squamatus. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2.
<www.iucnredlist.org>. Downloaded on 20 April 2012.

Auckland Islands Merganser
, Mergus australis

The Auckland Islands Merganser, Mergus australis,
was a typical merganser which is now extinct.

© http://www.bbfish.net/pet/pet_6054.html

The Auckland Merganser or Auckland Islands Merganser, Mergus australis, was a typical merganser which is now extinct.

This duck was similar in size to the Red-breasted Merganser. The adult male had a dark reddish-brown head, crest and neck,
with bluish black mantle and tail and slate grey wings. The female was slightly smaller with a shorter crest.

This bird was first collected when a French expedition led by the explorer Jules Dumont d'Urville on the ships L'Astrolabe and
La Zelee visited the Auckland Islands in 1840. Its decline was caused by a combination of hunting and predation by introduced
mammals. The bird was not flightless, but rather hard to flush; it preferred to hide between rocks when pursued. The last sighting
was of a pair shot on January 9, 1902. It was not found in a 1909 search, and a thorough 1972/1973 exploration of possible habitat concluded that it was long extinct.


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