Mergus serrator   Linnaeus,  1758 (Bird)
Organism information awaits expert curation
Class: Aves

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Size: 55-58 cm.

Voice: Generally silent.

Habits: Sociable, occur in small flocks, diurnal, feeds by diving.

Male: Head greenish-black with scraggy backward-directed crest, neck collar white and broad, upper breast dark chestnut blotched with black, upperparts white, iris red-brown, bill orange-red, edge of culmen and nail black, legs and feet orange-red. Male (eclipse): Like female but with dark mantle and more or less similar wings as in breeding males. Female: Head and neck pale chestnut with scraggy crest, ill-defined white throat, dark greyish-brown upper parts, with pale scalloping, white underparts, and ashy-brown mottled sides and breast. Young (immature) male like adult female, but overall more brown less grey. Crest shorter; bare parts duller colored.

Breeding: Season, breeds from April or May. Nest, large, compact, of moss, etc. lined with dense cover of bushes, or in holes in banks and cliffs. Eggs, 7 to 12 greyish to greenish buff.

Synonym (s)
Mergus serrator serrator (Linnaeus, 1758)

Common Name (s)
• Red-breasted Merganser (English)
• Redbreasted Merganser (English)
Economic Importance and Threats
Importance:  Ecosystem balance
(Red-breasted mergansers are important predators of small fish in their wetland habitats. Several bird species take advantage of the fact that red-breasted mergansers will herd fish prey to the water's surface when they are foraging. Snowy egrets, Bonaparte's, and ring-billed gulls will wait at the surface to grab fish scared by merganser foraging. Red-breasted mergansers are also attracted to areas where gulls are feeding on schooling fish.

Red-breasted mergansers are parasitized by at least 60 kinds of parasitic worms, including Eustrongylides species, which may cause die-offs. They are also parasitized by ectoparasites, such as lice (Anaticola crassicornis, Anatoecus dentatus, Anatoecus icterodes, Holomenopon loomisi, Pseudomenopon species, and Trinoton querquedulae).)
Importance:  Commercial
(Red-breasted mergansers are occasionally hunted, but they are not a common game bird also eggs of species are used.)
Importance:  Dangers
(Red-breasted mergansers are sometimes attracted to fish hatcheries and other commercial fish raising programs, as well as important salmon spawning streams. They are sometimes persecuted because of their predation on salmon parr (young salmon))
Threats:  Anthropogenic
(The species is subject to persecution and may be shot by anglers and fish-farmers who accuse it of depleting fish stocks. It is also threatened by accidental entanglement and drowning in fishing nets. Alterations to its breeding habitats by dam construction and deforestation, and habitat degradation from water pollution are other major threats to the species.)
Threats:  Natural threats
(It is also susceptible to avian influenza so may the threatened by future outbreaks of the virus)

Habitat:  Coastal
Trophic Level:  Consumer
Prey:  Carnivorous, mainly fish, crustaceans, insects, worms, and amphibians
Predator:  common ravens (Corvus corax) great black-backed gulls (Larus marinus) herring gulls (Larus argentatus) parasitic jaegers (Stercorarius parasiticus) mink (Neovison vison) great horned owls (Bubo virginianus) gyrfalcons (Falco rusticolis) red foxes (Vulpes vulpes) snowy owls (Nyctea scandiaca)
IUCN Status:  Least Concern


• West Bengal INDIA

Literature Source(s)
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • Myers, P; Espinosa, R; Parr, CS; Jones, T; Hammond, GS and Dewey, TA (2006) Animal diversity web Available at -
  • (2003) IUCN Red list of threatened species Available at -
  • Kumar, A; Sati, JP; Tak, PC and Alfred, JRB (2005) Handbook on Indian wetland birds and their conservation Zoological Survey of India, Dehra Dun 468 pp Available at - NIO, Goa
  • PBase Available at -
  • Vernacular names of the Birds of the Indian Subcontinent Buceros, Envis newsletter: Avian Ecology & Inland Wetlands 62pp Available at -
  • Manakadan R and Pittie A (2001) Standardized English names of the Birds of the Indian Subcontinent BUCEROS Envis Newsletter: Avian ecology and inland wetland 6(1) 26pp Available at -
  • Kumar A, sati JP and Tak CK (2003) Checklist of Indian Waterbids Buceros Envis Newsletter: Avian ecology and inland wetlands 8(1) 30pp Available at -
  • Ali S and Ripley SD (1968) Handbook of the birds of India and Pakistan Oxford university press 1 1-368pp Available at - NIO

Page last updated on:2012-08-13

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