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The UK Bird Atlas

Black Tern (Chlidonias niger)Where and when to see it in the UK

Status not yet classified · reporting peaks August to September · Skimmers, Noddies, Terns, and Gulls · BOU category A

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

Black Tern (Chlidonias niger)
USGov, Public domain, via Wikimedia Commons
Peak months
Black Tern: 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.

Black Tern has been recorded in 505 of the 2,971 10 km squares covering UK land (17%) in records to 2026. Its strongest squares are in England, Wales and Scotland. Reporting peaks in August to September.

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
14% or more of visits
High
2% to 14%
Moderate
<1% to 2%
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 26%<1%Low
May 47%<1%Moderate
June 26%<1%Low
July 19%<1%Low
August 100%1%High
September 95%1%High
October 12%<1%Low
November 2%<1%High
December 0%<1%Very high

Squares with the highest reporting rate in August

SquareWhereShare of visitsClass
HU31Shetland Islands, Scotland100%Very high
NK02Aberdeenshire, Scotland100%Very high
NK05Aberdeenshire, Scotland100%Very high
NO53Angus, Scotland100%Very high
NO75Angus, Scotland100%Very high
NU21Northumberland, England100%Very high
SD34Lancashire, England100%Very high
SE36North Yorkshire, England100%Very high
SE83East Riding of Yorkshire, England100%Very high
SH39Isle of Anglesey, Wales100%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.