• Skip to Content
  • Skip to Main Navigation
  • Skip to Local Navigation
  • Skip to Search
  • Skip to Sitemap
  • Skip to Footer
Help develop a Bird ID tool!

Forster's Tern

Sterna forsteri ORDER: CHARADRIIFORMES FAMILY: LARIDAE

IUCN Conservation Status: Least Concern

One of several medium-sized terns that are similar in appearance, the Forster's Tern breeds primarily in marshes and winters along the coasts. The comma-shaped black ear patch in winter plumage is distinctive, but some other plumages are very confusing.

Merlin Bird ID app
YardMap Be on the Map

At a GlanceHelp

Measurements
Both Sexes
Length
13–14.2 in
33–36 cm
Weight
4.6–6.7 oz
130–190 g
Other Names
  • Sterne de Forster (French)
  • Gaviote de Forster, Charran de Forster (Spanish)

Cool Facts

  • Forster's Tern is the only tern restricted almost entirely to North America throughout the year.
  • Spawning common carp are so vigorous that they can dislodge Forster's Tern eggs from floating nests.
  • Forster's and Black terns breed near each other in marshes. Wandering semi-precocial young may account for observations of each species feeding the other's young.

Habitat


Marsh

  • Breeds in marshes, generally with lots of open water and large stands of island-like vegetation.
  • Winters in marshes, coastal beaches, lakes, and rivers.

Food


Fish

Small fish and arthropods.

Nesting

Nesting Facts
Clutch Size
1–6 eggs
Egg Description
Olive to buff, marked with numerous small spots and blotches of dark brown, often concentrated around the larger end.
Condition at Hatching
Downy, eyes open, able to walk but stays in nest.
Nest Description

Varies from unlined scrape in mud or sand, to elaborate raft of floating vegetation, or on top of a muskrat lodge. Typically placed in clumps of marsh vegetation close to open water.

Nest Placement

Floating

Behavior


Aerial Dive

Plunges into water from flight; may hover briefly before plunging.

Conservation

status via IUCN

Least Concern

Species of special concern in the Midwestern states because of declines resulting from loss of wetland habitat.

Credits

  • McNicholl, M. K., P. E. Lowther, and J. A. Hall. 2001. Forster's Tern (Sterna forsteri). In The Birds of North America, No. 595 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

Range Map Help

Forster
View dynamic map of eBird sightings