Least Tern

Sternula antillarum




Gulls, Terns, Skimmers (Laridae)

Code 4


Code 6



Egg Color:

Buff to pale green with black, gray or brown marks.

Number of Eggs:

1 - 3

Incubation Days:

20 - 25

Egg Incubator:

Both sexes

Nest Location:

In sand.

Nest Material:

Lined with shell fragments and grass.





Least Tern: Small tern with slate-gray upperparts and white underparts. Crown and nape are black, forehead is white. Black leading edge of outer wing is clearly visible in flight, rump and tail slightly more gray. Tail is forked. Bill is bright yellow with a black tip; feet are bright yellow. Sexes are similar. Juvenile and winter adult have brown-and-white mottled upperparts. First-summer birds have a dark carpal bar and either a yellow bill and white flecking on a black crown or black bill and white forecrown and black eye stripe and nape.

Range and Habitat

Least Tern: Breeds along California coast, along rivers in Mississippi Valley, and from Maine south to Florida and the Gulf coast. Winters along coasts of Central and northern South America. Prefers broad, level expanses of open sandy or gravelly beach, dredge spoil and other open shoreline areas, and broad river valley sandbars.

Breeding and Nesting

Least Tern: They breed on broad level expanses of open sandy or gravelly beaches, dredge spoil and other open shoreline areas, and more rarely, inland on broad river valley sandbars. One to three buff to pale green eggs marked with black, gray or brown are laid in a scrape in the sand, shells or pebbles. Incubation ranges from 20 to 25 days and is carried out by both parents.

Foraging and Feeding

Least Tern: These terns feed mainly on small fishes, shrimp, and sometimes other invertebrates. They forage in a variety of shallow-water habitats. On marine coasts, they feed in bays, lagoons, estuaries, river and creek mouths, tidal marshes and lakes; occasionally they feed offshore. Inland feeding sites include rivers, streams, sloughs, dike fields, marshes, ponds, sand pits and reservoirs.


Least Tern: Call is a sharp, penetrating "kip-kip-kip" or shrill "zreep."

Similar Species

Least Tern: Black Tern has dark gray upperparts and tail and is entirely black below.


Belly, undertail coverts, chest, flanks, and foreneck.

Back, rump, hindneck, wings, and crown.
The crown is the top part of the birds head.
Also called the hindneck or collar, it is the back of the neck where the head joins the body.
Outer wingX
The alula and the primary feathers.
The area between the uppertail coverts and the back of the bird.
Parts of a Standing bird X
Head Feathers and Markings X
Parts of a Flying bird X