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The UK Bird Atlas

Marsh Harrier (Circus aeruginosus)Where and when to see it in the UK

Resident · reporting peaks April to May · Kites, Old World Vultures, Eagles, and Hawks · BOU category AF

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

Marsh Harrier (Circus aeruginosus)
Subramanya CK, CC BY-SA 3.0, via Wikimedia Commons
Peak months
Marsh Harrier: 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.

Marsh Harrier has been recorded in 1,173 of the 2,971 10 km squares covering UK land (39%) in records to 2026. Resident in the UK. Its strongest squares are in England, Scotland and Wales. Reporting peaks in April to May.

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
50% or more of visits
High
12% to 50%
Moderate
3% to 12%
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

Seasonality

Reporting rate by month, relative to the peak month
MonthRelative to peakShare of visitsTypical class
January 97%9%High
February 86%8%High
March 76%7%Very high
April 88%8%Low
May 91%8%Low
June 77%7%Very high
July 77%7%Very high
August 81%7%Very high
September 86%8%Very high
October 100%9%Low
November 99%9%High
December 92%8%High

Squares with the highest reporting rate in January

SquareWhereShare of visitsClass
NH80Highland, Scotland100%Very high
NO34Angus, Scotland100%Very high
NO42Fife, Scotland100%Very high
NU14Northumberland, England100%Very high
NU20Northumberland, England100%Very high
NU21Northumberland, England100%Very high
NX76Dumfries and Galloway, Scotland100%Very high
NX95Dumfries and Galloway, Scotland100%Very high
NZ28Northumberland, England100%Very high
NZ45Sunderland, England100%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.