Wildlife Clinic

Species

Black tern

Chlidonias niger

A small, dark marsh tern that passes Georgia's coast in late summer on its way to South America.

A black tern in breeding plumage perched on a weathered stump over blue water, its black head and grey wings in profile.

Photo Craig K (opens in a new tab) / iNaturalist, CC BY 4.0 (opens in a new tab)

At a glance

Size
About 23 to 26 cm long
Weight
About 50 to 70 g
Habitat
Freshwater marshes in summer; coastal waters and lakes on migration
Diet
Insects, small fish and crustaceans
In Georgia
A common migrant offshore and on the coast, July to October
Voice
A sharp "kik"
Rabies vector
No

Identification

Key marks
In summer, black head and body with grey wings; in autumn white below with a dark cap and a dark mark on the side of the breast
Told apart from
Least tern, which is white with a yellow bill
Where to look
Offshore and over coastal waters in August and September

Behaviour

Black terns pick insects and small fish from the surface in buoyant, erratic flight, rarely plunging.

Why they matter

Black terns have declined as the freshwater marshes where they nest have been drained. On migration they gather over the ocean, feeding on small fish pushed to the surface.

Reproduction and lifecycle

Nest — A floating mat of plants in marshes
Eggs — Usually three
Incubation — About 21 to 22 days
Chicks — Fed by both parents
Flight — At about three weeks
Lifespan — Several years

Living around people

  • Black terns are rarely near people in Georgia, but those blown inland by storms may need help.

Misconceptions

  • A tern this dark is a young bird. Adult black terns are dark in summer.

Related species

Seasonal activity

When this species is breeding, and when there are nests on the ground. Mowing during the shaded months is how most nests are found.

Breeding and active nests by month for this species
JanFebMarAprMayJunJulAugSepOctNovDec
BreedingJan: noFeb: noMar: noApr: noMay: noJun: noJul: noAug: noSep: noOct: noNov: noDec: no
Active nestsJan: noFeb: noMar: noApr: noMay: noJun: noJul: noAug: noSep: noOct: noNov: noDec: no
NotesIn South AmericaIn South AmericaIn South AmericaMigrating northMigrants passingNesting on northern marshesMigrants arrivingPeak migrationMigrantsLast migrantsIn South AmericaIn South America

Where it lives

Recorded in 69 states and provinces. Each one links to the other animals there, and to the rehabilitators licensed for them.

If you found one

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