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The UK Bird Atlas

Smew (Mergellus albellus)Where and when to see it in the UK

Winter visitor · reporting peaks January · Ducks, Swans, and Geese · BOU category AF

Records to 2026-08-16 · build 2026-08-31

Smew (Mergellus albellus)
Andreas Trepte, CC BY-SA 2.5, via Wikimedia Commons
Peak months
Smew: relative reporting rate by 10 km square, September

Contains OS data © Crown copyright and database right 2026 (grid squares, place names from OS Open Names). Northern Ireland place names: OSNI Open Data, OGL v3.0. County and country boundaries: Office for National Statistics, Open Government Licence v3.0. Coastline: Natural Earth. Bird records from the data partners listed here.

Smew has been recorded in 409 of the 2,971 10 km squares covering UK land (14%) in records to 2026. Winter visitor in the UK. Its strongest squares are in England, Scotland and Wales. Reporting peaks in January.

Conservation status: Least Concern (IUCN Red List, LC)
View on the IUCN Red List
Relative to this species' best squares (how classes are calculated)
Very high
100% or more of visits
High
6% to 100%
Moderate
<1% to 6%
Low
under <1%
Surveyed, not recorded
at least 20 qualifying visits, no record
Insufficient records
too few visits to say
Lighter fill
Few visits, lower confidence
Small dot
Occasional: a single record, or out of season

Seasonality

Reporting rate by month, relative to the peak month
MonthRelative to peakShare of visitsTypical class
January 100%1%Low
February 85%1%Very high
March 47%<1%Moderate
April 5%<1%Moderate
May 0%<1%Very high
June 1%<1%Very high
July 0%<1%Very high
August 0%<1%Very high
September 0%<1%Very high
October 2%<1%Very high
November 14%<1%Very high
December 56%<1%Moderate

Squares with the highest reporting rate in January

SquareWhereShare of visitsClass
H15Fermanagh and Omagh, Northern Ireland100%Very high
H24Fermanagh and Omagh, Northern Ireland100%Very high
H96Armagh City, Banbridge and Craigavon, Northern Ireland100%Very high
HP60Shetland Islands, Scotland100%Very high
NH87Highland, Scotland100%Very high
NJ90Aberdeen City, Scotland100%Very high
NO31Fife, Scotland100%Very high
NO35Angus, Scotland100%Very high
NO42Fife, Scotland100%Very high
NS41East Ayrshire, Scotland100%Very high

Spotted an error in a square? Report it and it goes into the review queue. Read the methodology for how classes, flags and sensitive-species rules work. Data to 2026.