Common tern migration Sterna hirundo
▶ Follow the common tern across the big globe
Press ▶ to play the year. Line: a simplified typical route, joining the main cluster of GBIF records in each month (adjusted for observer effort).
| Scientific name | Sterna hirundo |
|---|---|
| Wingspan | 88 cm |
| IUCN status | Least concern |
| Records mapped | 2,316,875 (GBIF) |
| GPS / geolocator tracks | none with an open licence yet |
Facts from Wikidata Q18875 (CC0).
When does the common tern arrive in the UK?
A summer visitor in the records: sightings rise sharply from mid April, are near their peak by late April, and fall away after mid September.
Bars: this species’ share of all UK bird records in GBIF (CC0/CC BY), by month, scaled to the peak month. Based on 155,813 UK records. Weekly counts from the GBIF occurrence search API (country=GB). Dates are read from records, not from a survey, so treat them as a guide.
When do they arrive in and leave the UK? →
Migration in the data
2,316,875 GBIF records (CC0 and CC BY 4.0 licences only) are mapped here, in 1.41° grid cells, month by month.
In Europe and Africa, the centre of the records (adjusted for observer effort) is furthest north in July (about 50°N) and furthest south in February (about 9°S).
More than half of the effort-adjusted signal there is south of the Equator in: January, February, November, December.
Month by month: centre of records in Europe and Africa
| Month | Centre (latitude) | South of the Equator |
|---|---|---|
| January | 7°N | 50% |
| February | 9°S | 68% |
| March | 6°N | 45% |
| April | 40°N | 7% |
| May | 48°N | 3% |
| June | 49°N | 2% |
| July | 50°N | 2% |
| August | 47°N | 4% |
| September | 37°N | 10% |
| October | 20°N | 30% |
| November | 0°N | 54% |
| December | 9°S | 70% |
Tracked birds
No openly licensed (CC0 / CC BY) tracking data package for this species was found in the Movebank Data Repository yet, so only records are shown.
About the common tern
The common tern is a seabird in the family Laridae. This bird has a circumpolar distribution, its four subspecies breeding in temperate and subarctic regions of Europe, Asia and North America. It is strongly migratory, wintering in coastal tropical and subtropical regions. Breeding adults have light grey upperparts, white to very light grey underparts, a black cap, orange-red legs, and a narrow pointed bill. …
From the Wikipedia article “Common tern” (revision 1380659743), CC BY-SA 4.0.
Sources
GBIF occurrence records, licence CC0 1.0 or CC BY 4.0 only, observations only (no specimens), filtered with: taxonKey=9367409&license=CC0_1_0&license=CC_BY_4_0&occurrenceStatus=PRESENT&hasGeospatialIssue=false&basisOfRecord=HUMAN_OBSERVATION&basisOfRecord=MACHINE_OBSERVATION&basisOfRecord=OBSERVATION. Monthly queries: Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec. GBIF.org (23 October 2026) occurrence data accessed via the GBIF API; a GBIF download DOI is still to be added. Contributing datasets.