A small tern that visits Japan in warmer months to breed on beaches and river bars.
In Japanese adults in breeding plumage, the crown is black and the forehead white; the yellow bill has a small black tip.
Little Terns nest on beaches with different amounts of vegetation in different regions. A 1992 survey of 18 breeding colonies on coasts and rivers in south Kanto, Japan, found colonies on sandy ground with vegetation cover of 5% or less. Stones and other possible landmarks were often found near nests.
In Norfolk and Suffolk, eastern England, a 2003 survey of 68 one-kilometre beach sections found colonies in 19 sections. A model estimated a 23% chance of colony occurrence where vegetation was absent and 70% where cover was 20%. Colony occurrence fell as the average number of people per kilometre increased; the model estimate reached 0% above 25 people. The two regional studies record different vegetation patterns and link colony locations with local beach conditions and human use.
IUCN Red List · Least Concern (LC) · Global, species-level assessment
The Little Tern was assessed as Least Concern (LC) globally in the 2018 IUCN Red List. BirdLife International’s assessment history explains that its very large range and population, together with a decline not considered rapid enough to meet a threatened-category threshold, support that classification. The same record notes that trends are unknown or increasing in some regional populations. Field studies in south Kanto, Japan, reported loss of sandy coastal and river sites suitable for nesting; in East Anglia, England, colony occurrence was lower on beaches with more people. The regional studies recommend maintaining suitable breeding habitat and managing access to colonies.