Least Tern

Sternula antillarum

Least Terns are the smallest of all North American terns. They prefer to nest on sandy beaches along bays, lagoons or freshwater wetlands and waterways. Their nesting habitat is often preferred for recreation by homosapiens, so they have suffered a population crash. Though at some locations the populations seem stable, between 1966 and 2015, their overall numbers dropped by 88%.

The California Least Tern (S.a. browni) was listed as an endangered species in 1972 with a population of about 600 pairs. While numbers have gradually increased with its protected status, it is still vulnerable to predators, natural disasters, and further disturbance by humans.

There are two more subspecies of Least Tern recognised by science. S. a. athalassos breeds in the interior USA, and S. a. antillarum breeds on the Atlantic coast. The Atlantic group is not considered threatened, but the interior population is. We believe loss of habitat from dams and changes to river systems to be the cause.

Click map markers to reveal further information