
Sterna hirundo
Namib-Naukluft, West Coast National Park and Dorob National Park are three atlas places where the Common Tern is recorded. Records concentrate most heavily in the United States, Canada, Finland, the United Kingdom and Norway. The atlas holds about 836,000 records of this bird from 21 countries, and the map reflects where these observations cluster.
Because the species is recorded in both the northern and southern hemispheres, the months it is most active differ by region. Each place page in the atlas shows the recorded timing for that area.
These are open occurrence records, so they show where people looked for and recorded the Common Tern as much as where it lives. The atlas keeps a species' 200 best-recorded grid cells, so the map shows where records concentrate rather than its whole range. Cells are up to 25 km across, and every location is generalised to its cell.
Generalised encounter areas, not exact locations. Each shape is a grid cell coloured by how likely the species is there.
Conservation status not assessed here yet, so every location is generalised to its grid cell.