Chlidonias niger
Drawn from open occurrence records in and around Joshua Tree National Park, aggregated onto a 25 km grid. A cell is matched by its centre, which can sit up to 16 km outside the boundary, so this covers the surrounding country too.
Occurrence records measure where people looked and found something, which is not the same as where the animal is. This is a relative likelihood, not a probability.
Records exist for April, May, June, July, August, September and October, with the widest coverage in April, May, June, July, August, September and October. A quiet month can mean the animal was absent, or that nobody was looking.
A grid cell is a square of the map, not a sighting: 1 square of 25 km carry records for Black Tern in and around Joshua Tree National Park, and the 562 records behind them were collected by other people and published openly. Nothing here counts animals, and a place with more records is not always a place with more animals.
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.
Of the 8 species with an atlas page recorded in and around Joshua Tree National Park, the Black Tern is the 7th most recorded.
The full atlas page, and everywhere else it is recorded