Red-breasted Merganser (Mergus serrator)Where and when to see it in the UK
Resident · reporting peaks November to February · Ducks, Swans, and Geese · BOU category AF
Peak months
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.
Red-breasted Merganser has been recorded in 1,311 of the 2,971 10 km squares covering UK land (44%) in records to 2026. Resident in the UK. Its strongest squares are in Scotland, England and Wales. Reporting peaks in November to February.
Conservation status: Least Concern (IUCN Red List, LC)
View on the IUCN Red List- Very high
- 32% or more of visits
- High
- 11% to 32%
- Moderate
- 3% to 11%
- Low
- under 3%
- 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
Relative to this species' best squares (how classes are calculated)
Seasonality
| Month | Relative to peak | Share of visits | Typical class |
|---|---|---|---|
| January | 100% | 4% | Very high |
| February | 87% | 4% | Very high |
| March | 67% | 3% | Very high |
| April | 45% | 2% | Very high |
| May | 39% | 2% | Very high |
| June | 37% | 2% | Very high |
| July | 21% | <1% | Very high |
| August | 16% | <1% | Moderate |
| September | 32% | 1% | Moderate |
| October | 67% | 3% | Very high |
| November | 91% | 4% | Very high |
| December | 91% | 4% | Very high |
Squares with the highest reporting rate in January
| Square | Where | Share of visits | Class |
|---|---|---|---|
| C62 | Causeway Coast and Glens, Northern Ireland | 100% | Very high |
| H15 | Fermanagh and Omagh, Northern Ireland | 100% | Very high |
| HY42 | Orkney Islands, Scotland | 100% | Very high |
| HY74 | Orkney Islands, Scotland | 100% | Very high |
| J21 | Newry, Mourne and Down, Northern Ireland | 100% | Very high |
| J33 | Newry, Mourne and Down, Northern Ireland | 100% | Very high |
| J43 | Newry, Mourne and Down, Northern Ireland | 100% | Very high |
| J48 | Ards and North Down, Northern Ireland | 100% | Very high |
| J65 | Ards and North Down, Northern Ireland | 100% | Very high |
| J67 | Ards and North Down, Northern Ireland | 100% | Very high |