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Forster's Tern


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.

At a GlanceHelp

Both Sexes
13–14.2 in
33–36 cm
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.
  • The oldest known Forster's Tern was at least 15 years, 10 months old when it was killed by contaminants in California in 1989. It had been banded in the same state in 1973.



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



Small fish and arthropods.


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



Aerial Dive

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


status via IUCN

Least Concern

Forster's Tern appear to have experienced declines between 1966 and 2015 according to the North American Breeding Bird Survey, but there is not enough data to estimate numbers with certainty. The North American Waterbird Conservation Plan estimates between 47,000-51,500 continental breeding birds, and lists it as a Species of Moderate Concern. Forster's Tern ranks an 11 out of 20 on the Continental Concern Score. The species is not on the 2016 State of North America's Birds Watch List, but is of special concern in some states due to declines resulting from the loss of wetland habitat.


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