Bittern (Botaurus stellaris)Where and when to see it in the UK
Resident · reporting peaks May · Herons, Egrets, and Bitterns · 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.
Bittern has been recorded in 464 of the 2,971 10 km squares covering UK land (16%) in records to 2026. Resident in the UK. Its strongest squares are in England, Wales and Scotland. Reporting peaks in May.
Conservation status: Least Concern (IUCN Red List, LC)
View on the IUCN Red List- 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
Relative to this species' best squares (how classes are calculated)
Seasonality
| Month | Relative to peak | Share of visits | Typical class |
|---|---|---|---|
| January | 24% | <1% | Very high |
| February | 27% | <1% | Very high |
| March | 44% | 1% | Very high |
| April | 77% | 2% | High |
| May | 100% | 3% | High |
| June | 63% | 2% | High |
| July | 32% | <1% | Very high |
| August | 22% | <1% | Very high |
| September | 16% | <1% | Low |
| October | 21% | <1% | Very high |
| November | 20% | <1% | Very high |
| December | 19% | <1% | Very high |
Squares with the highest reporting rate in May
| Square | Where | Share of visits | Class |
|---|---|---|---|
| NY96 | Northumberland, England | 100% | Very high |
| NZ29 | Northumberland, England | 100% | Very high |
| SD41 | Lancashire, England | 100% | Very high |
| SD57 | Lancashire, England | 100% | Very high |
| SK31 | Leicestershire, England | 100% | Very high |
| SK50 | Leicestershire, England | 100% | Very high |
| SK58 | Rotherham, England | 100% | Very high |
| SK59 | Doncaster, England | 100% | Very high |
| SK61 | Leicestershire, England | 100% | Very high |
| SK69 | Doncaster, England | 100% | Very high |