Birds
Black Tern
Chlidonias niger · also called black terns
Hovering low over a freshwater marsh before dipping down to snatch an insect from the surface, a black tern breaks almost every rule of what a typical tern looks like, its breeding plumage a near-total black instead of the usual pale grey and white.
Overview
The black tern, Chlidonias niger, is a freshwater marsh specialist native to wetland habitat across parts of North America, Europe, and Asia. Its striking near-black breeding plumage, unusual inland marsh habitat far from any coast, and hovering-and-dipping hunting style set it apart sharply from the pale, plunge-diving coastal terns that make up most of the wider tern family.
A tern that left the coast behind
While most terns are creatures of open coastlines and ocean, the black tern has carved out a life entirely within freshwater marshes, trading plunge dives into salt water for a gentler hover-and-dip hunting style over still, inland water.
Status
Least Concern globally, though declining in parts of its range due to loss of the freshwater marsh habitat it depends on for breeding.
Black Tern: common questions
Where does the black tern breed, if not on beaches?
This species breeds on freshwater marshes and wetlands far from any coast, unlike most other terns, which nest along beaches and coastal islands, making it one of the more inland-focused members of the entire tern family.
Why is the black tern actually black?
This species develops an almost entirely black body and head during the breeding season, a striking departure from the pale grey and white plumage typical of most other terns, though it turns pale and mottled again outside the breeding season.
How does the black tern catch its food?
This species hunts mainly by hovering low over the water and dipping down to snatch insects and small fish, rather than the high plunge dives used by many coastal tern species.
Why is the black tern declining in parts of its range?
This species has declined due to the loss and degradation of the freshwater marsh habitat it depends on for breeding, a specialised habitat requirement that leaves it more vulnerable to wetland drainage than coastal tern species.