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Great Reed Warbler (Acrocephalus arundinaceus)Where and when to see it in the UK

Status not yet classified · reporting peaks May · Reed Warblers and Allies · BOU category A

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

Great Reed Warbler (Acrocephalus arundinaceus)
Олександр Матвійчук, CC BY-SA 4.0, via Wikimedia Commons
Peak months
Great Reed Warbler: 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.

Great Reed Warbler has been recorded in 74 of the 2,971 10 km squares covering UK land (2%) in records to 2026. Its strongest squares are in England and Scotland. Reporting peaks in 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
100% or more of visits
High
4% to 100%
Moderate
<1% to 4%
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 0%<1%Insufficient records
February 0%<1%Insufficient records
March 0%<1%Very high
April 4%<1%Very high
May 100%<1%Moderate
June 83%<1%Very high
July 0%<1%Moderate
August 0%<1%Moderate
September 0%<1%Very high
October 0%<1%Very high
November 0%<1%Very high
December 0%<1%Insufficient records

Squares with the highest reporting rate in May

SquareWhereShare of visitsClass
NZ29Northumberland, England100%Very high
SE21Kirklees, England100%Very high
SK68Nottinghamshire, England100%Very high
SO86Worcestershire, England100%Very high
ST35Somerset, England100%Very high
ST46North Somerset, England100%Very high
ST55Somerset, England100%Very high
SU40Hampshire, England100%Very high
SW61Cornwall, England100%Very high
TA14East Riding of Yorkshire, 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.