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
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.