Smew
Mergellus albellus
Visual Identification
Appearance
The Smew is a small, distinctive diving duck. Males are primarily white with intricate black markings, including a black eye patch and fine lines on the sides. They have a crested head and a thin, serrated grey bill.
Females are predominantly grey with a chestnut-brown head and white cheek patch. Both sexes have grey legs and feet and a vague crest on the back of their head.
Non-breeding males moult into an eclipse plumage that is fairly similar to the colouring of a female but retains their black backs and white wing patches. Juveniles resemble females but with duller plumage.
Size
Length
38cm to 44cm
Wingspan
55cm to 69cm
Weight
450g to 650g
Habitat and Distribution
Habitats
Woodland
Garden
Wetland
Coastal
Urban
Farmland
Grassland
Desert
Tundra
Rainforest
Mountain
Savanna
Distribution
Smews breed in northern taiga forests across Scandinavia and Russia, nesting near freshwater lakes and rivers. During winter, they migrate to coastal areas and inland waters of central and southern Europe, including the UK, as well as parts of Asia.
In the UK, Smews are winter visitors found in reservoirs, lakes, and estuaries. They are more common in eastern and southern England, with smaller numbers reaching Scotland and Wales. The most common sightings are usually from Lincolnshire to the Severn estuary.
Elevation Range
Up to 2,000 meters
Climate zones
Temperate, Subarctic
Distribution Map
This map gives you a rough idea of where you might spot a Smew. The coloured areas show countries where these birds have been seen.
A few things to keep in mind:
- Birds might not be everywhere in the coloured areas, for example, they may be present around the coast of that country
- Where birds live can change with seasons and available food
- This map is quite simple - it doesn't show exact locations
We're working on making our maps even better! Soon, we hope to show you:
- More detailed maps for bigger countries, including state and region
- How birds move around during different seasons
Distribution by Region
Behaviour and Ecology
Bird Attributes
This feature is in beta. We'd love your feedback to improve it!
Share your thoughtsBird Attributes Explained
Our bird attributes system rates various aspects of a bird's capabilities on a scale of 0-100, based on data from field observations, scientific studies, and expert knowledge.
Attribute Categories:
- Agility: Manoeuvrability, speed, and grace in flight or movement.
- Strength: Physical power, often correlating with size and hunting abilities.
- Adaptability: Ability to thrive in various environments or changing conditions.
- Aggressiveness: Territorial behaviour and assertiveness, particularly during breeding seasons.
- Endurance: Stamina, often seen in migration patterns or foraging behaviours.
Understanding the Ratings:
- 0-20: Very Low
- 21-40: Low
- 41-60: Average
- 61-80: High
- 81-100: Very High
Remember, these attributes are relative to other bird species and don't necessarily indicate superiority.
Hover over the icon next to each attribute for more information.
Tap the icon next to each attribute for more information.
Agility
Reflects the bird's manoeuvrability, speed, and grace in flight or movement.
The Smew demonstrates remarkable agility, particularly in aquatic environments. As skilled divers, they can submerge for 15-30 seconds whilst foraging, showcasing their nimble underwater manoeuvrability. Their ability to perform elaborate courtship displays, including head-throws and backward kicks on the water surface, further attests to their agility.
Strength
Indicates the bird's physical power, often correlating with size and hunting abilities.
Whilst not exceptionally strong for their size, Smews possess adequate strength for their lifestyle. Their ability to dive and hunt underwater, grasping slippery prey with their serrated bills, indicates a moderate level of strength. However, as small diving ducks, they are not built for feats of great power.
Adaptability
Represents the bird's ability to thrive in various environments or changing conditions.
Smews exhibit good adaptability, thriving in various aquatic habitats from breeding grounds in taiga forests to wintering sites in coastal areas and inland waters. Their ability to nest in tree cavities or artificial nest boxes demonstrates flexibility. Their diverse diet, including fish, aquatic insects, and some plant material, also suggests adaptability to different food sources.
Aggressiveness
Measures the bird's territorial behaviour and assertiveness, particularly during breeding seasons.
Smews are not particularly aggressive birds. They are typically seen in small flocks and can mix with other diving ducks, indicating a relatively peaceful nature. However, like most birds, they likely display some territorial behaviour during breeding season, hence the moderate score.
Endurance
Reflects the bird's stamina, often seen in migration patterns or foraging behaviours.
The Smew's endurance is noteworthy, particularly considering their long-distance migrations between breeding and wintering grounds. Their ability to dive repeatedly for food and withstand cold temperatures in their northern habitats also indicates good endurance. However, as small birds, they may not have the extreme endurance of larger migratory species.
Diet
Smews primarily feed on small fish, aquatic insects, amphibians, and crustaceans. They are skilled underwater hunters, using their serrated bills to grasp slippery prey. During the breeding season, they may also consume some plant material, including seeds and aquatic vegetation.
In winter, more fish, including salmon, trout, gudgeon, herring, eels, and carp, are caught, depending on location, with both freshwater and saltwater species eaten.
Despite their small size, they are able to catch relatively large fish, with eels up to 29 cm not posing much of a problem!
Behaviour
Smews are agile swimmers and excellent divers, often submerging for 15-30 seconds while foraging. They are typically seen in small flocks during winter, sometimes mixing with other diving ducks.
During the breeding season, males perform elaborate courtship displays, including head-throws and backward kicks on the water surface.
Vocalisation
Smews are generally quiet birds. Males produce a soft, rattling 'krrr' during courtship displays. Females have a harsh, croaking call, described as a repeated 'kek-kek-kek'. When alarmed, both sexes may emit a sharp, grating sound.
Nesting & Breeding
Smews form monogamous pairs during the breeding season, which typically begins in May. Males court females with elaborate displays, including head-bobbing and water-splashing.
Females lay 6-9 cream-coloured eggs in tree cavities or nest boxes, often near water. The nest is lined with down feathers plucked from the female's breast.
Incubation lasts about 28 days, carried out solely by the female. Ducklings leave the nest within 24 hours of hatching and are capable of diving and feeding themselves, though they remain with the female for protection.
The male initially stands guard nearby, but as the incubation period progresses, leaves the breeding grounds and plays no active part in raising the ducklings once they hatch.
Conservation and Status
Global Conservation Status
While currently listed as Least Concern, Smews face threats from habitat loss and degradation of breeding areas. Climate change may also impact their distribution and migration patterns.
Conservation efforts focus on protecting wetland habitats and monitoring population trends across their range.
Birdwatching Tips
- Look for Smews on lakes, reservoirs, and coastal bays during winter months
- Scan for the striking white plumage of males, which stands out among other waterfowl
- Observe their diving behaviour, as they frequently submerge in search of food
- In the UK, check well-known wintering sites like Dungeness in Kent or Rutland Water
Additional Information
Quick Facts
Predators
Did You Know?
- The Smew is the only member of its genus, Mergellus.
- Their serrated bill is specially adapted for catching and holding slippery fish.
- The name 'Smew' is thought to derive from an old English word meaning 'smooth'.
FAQs
Is a Smew a sea duck?
The Smew is a sea duck. It is a small diving duck belonging to the family Anatidae.
How do you pronounce Smew?
Smew is pronounced as it is written ‘S-mew’, to rhyme with ‘new’.
References
- 1
website: BirdLife International. 2016. Mergellus albellus. The IUCN Red List of Threatened Species 2016: e.T22680465A85991357.
View source - 2 3
report, 2015: Wetlands International
- 4
website, 2010: Fransson et al., EURING list of longevity records for European birds
View source
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