- 12.2–15 in
- 29.5–31.5 in
- 3.3–7.1 oz
- Sterne pierregarin (French)
- Gaviotin común (Spanish)
- 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.
- The oldest recorded Common Tern was at least 25 years, 1 month old, when it was recaptured and rereleased during banding operations in New York.
Nests on islands, marshes, and sometimes beaches of lakes and ocean.
Small fish. Some invertebrates.
- 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.
Pile of dead vegetation on ground. May have no material.
Plunges into water from flight; may hover briefly before plunging.
Common Tern is the most widespread tern in North American, however, populations declined between 1966 and 2014, according to the North American Breeding Bird Survey. The North American Waterbird Conservation Plan estimates a population of 300,000 breeding birds on the continent and rates them an 11 out of 20 on the Continental Concern Score, and lists them as a Species of Low Concern. They are not on the 2014 State of the Birds Watch List. Common Tern populations severely depleted in late 19th century for millinery trade, but recovered with protection. However, populations had declined again by the 1970s, probably from pesticide poisoning. There has been some recovery since then, but the species is still in trouble in some areas. Common Tern are listed as endangered, threatened, or of special concern in many states.
- Nisbet, I. C. T. 2002. Common Tern (Sterna hirundo). In The Birds of North America, No. 618 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
- Kushlan, J.A., et al. 2002. Waterbird conservation for the Americas: the North American Waterbird Conservation Plan, version 1. Waterbird Conservation for the Americas. Washington, DC.
- North American Bird Conservation Initiative, U.S. Committee. 2014. State of the Birds 2014 Report. U.S. Department of Interior, Washington, DC.
- USGS Patuxent Wildlife Research Center. 2015. Longevity records of North American Birds.
- USGS Patuxent Wildlife Research Center. 2014. North American Breeding Bird Survey 1966–2014 Analysis.