Measurements
Both Sexes
- Length
- 12.2–15 in
31–38 cm - Wingspan
- 29.5–31.5 in
75–80 cm - Weight
- 3.3–7.1 oz
93–200 g
Other Names
- Sterne pierregarin (French)
- Gaviotin común (Spanish)
Cool Facts
- The Common Tern drinks mainly on the wing, gliding with its wings slightly raised and dipping its bill several times into the water.
- Common Terns living along the coast drink salt water. They do not seek fresh water even when it is available nearby. Like many seabirds, they have nasal glands that excrete the excess salt.
- The incubating adult Common Tern flies off its nest to defecate 5-50 m (16-160 ft) away. It deposits its feces indiscriminately in nearby water or on the territories of other terns.
Habitat
Shore-line
Nests on islands, marshes, and sometimes beaches of lakes and ocean.
Food
Fish
Small fish. Some invertebrates.
Nesting
Nesting Facts
- Clutch Size
- 1–4 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
Pile of dead vegetation on ground. May have no material.
Nest Placement
Ground
Behavior
Aerial Dive
Plunges into water from flight; may hover briefly before plunging.
Conservation
Least Concern
Populations severely depleted in late 19th century for millinery trade; recovered with protection. Declined again by 1970s, probably from pesticide poisoning. Some recovery since then, but still in trouble in some areas. Listed as endangered, threatened, or of special concern in many states.
Credits
- Nisbet, I. C. T. 2002. Common Tern (Sterna hirundo). In The Birds of North Americaa, No. 618 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.