
Chlidonias niger
Namib-Naukluft and Dorob National Park are the two atlas places where the Black Tern is recorded. Its records concentrate in the United States, Canada, Belgium, France and Spain, with about 229,000 records across 17 countries. This map follows where those records gather. Because this bird is recorded in both the northern and southern hemispheres, the seasons for seeing it differ by region. Each place page in the atlas shows the months recorded for that area.
These are open occurrence records, so they show where people looked for and recorded the Black 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.