Sterna hirundo
Drawn from open occurrence records in and around Acadia 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 May, June, July, August, September and October, with the widest coverage in May, June, July and August. 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: 4 squares of 25 km carry records for Common Tern in and around Acadia National Park, and the 12,290 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, 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.
Of the 16 species with an atlas page recorded in and around Acadia National Park, the Common Tern is the 2nd most recorded.
The full atlas page, and everywhere else it is recorded