Gull-billed Tern

Gelochelidon nilotica




Gulls, Terns, Skimmers (Laridae)

Code 4


Code 6



Egg Color:

Pink buff to yellow with sparse dark brown spots

Number of Eggs:

1 - 4

Incubation Days:

22 - 23

Egg Incubator:

Both sexes

Nest Location:

salt marches and beaches, on open ground, often concealed in debris among shells.

Nest Material:

Lined with plant material and debris; rimmed with sand, shells, sticks, and grass.





Gull-billed Tern: The lightest North American tern. Black cap that extends below the eyes and down the nape, and pale gray upperparts that are darker at the wingtips; short, stout black bill and long black legs; long wings with very long outer primaries.

Range and Habitat

Gull-billed Tern: During breeding season, they occur in the eastern and southern coastal United States. Also seen during the winter along the southern coastal United States. Its winter range extends to central coastal areas of South America. Breeding habitat includes sand, gravel, or shell beaches, or some grassy areas of coastal islands.

Breeding and Nesting

Gull-billed Tern: Monogamous; colonial or solitary. Often nest at periphery of other tern species' colonies. Nest on open ground, often concealed in debris among shells, built by both sexes; one to four pink buff to yellow eggs lightly spotted with dark brown. Incubation ranges from 22 to 23 days and is carried out by both sexes. Young fledge in 28-35 days. One brood per year.

Foraging and Feeding

Gull-billed Tern: Flies over farm fields or marshes to catch insects, its main diet. Over water, swoops to catch small prey; also eats frogs, crustaceans, and earthworms.


Gull-billed Tern: Call is "kay-WEK." Also raspy "ge-rek," or "kay-tih-DID." Alarm is rasping "aach."

Similar Species

Gull-billed Tern: Sandwich Tern has thinner wing, a black bill with a yellow tip, and a shorter crest.

Back, rump, hindneck, wings, and crown.
The area on top of the head of the bird.
Also called the hindneck or collar, it is the back of the neck where the head joins the body.
Outer primariesX
The outer primaries are the primary feathers on the wing farthest from the body. They often appear to be the longest feathers on the wing.
The primaries are the flight feathers specialized for flight. They are attached to the "hand" equivalent part of the wing.
Parts of a Standing bird X
Head Feathers and Markings X
Parts of a Flying bird X