- 13–15 in
- 35.8 in
- 5.3–7.2 oz
- Sterne hansel (French)
- Pico de gaviota, Golondrina playera (Spanish)
- Unlike most terns, the Gull-billed Tern has a broad diet and does not depend on fish. Instead it commonly feeds on insects, small crabs, and other prey snatched from the ground, air, or even bushes. It is also known to eat small chicks of other tern species.
- Although mostly restricted to salt water habitats in North America, the Gull-billed Tern is found in a variety of fresh water habitats across Eurasia.
- The oldest recorded Gull-billed Tern lived to be at least 20 years old and was found, and banded, in California.
Breeds on gravelly or sandy beaches. Winters in salt marshes, estuaries, lagoons and plowed fields, less frequently along rivers, around lakes and in fresh-water marshes.
Fish, insects, lizards, aquatic animals, occasionally chicks of other birds.
- Clutch Size
- 1–7 eggs
- Condition at Hatching
- Downy, eyes open, able to walk but stays in nest.
Plucks prey from ground while in flight, catches flying insects. Does not generally plunge-dive for fish.
Populations of Gull-billed Tern appear erratic, but overall were stable between 1966 and 2014—with the exception of California, where numbers declined by 98% during that time—according to the North American Breeding Bird Survey. The North American Waterbird Conservation Plan estimates between 6,000 to 8,000 breeding birds in North America. They rate the species a 14 out of 20 on the Continental Concern Score, and lists it a Species of High Concern. The North American population of Gull-billed Tern is on the 2014 State of the Birds Watch List, which lists bird species that are at risk of becoming threatened or endangered without conservation action. These birds are also listed as "species of special concern" in California.
- Parnell, J. F., R. M. Erwin, and K. C. Molina. 1995. Gull-billed Tern (Sterna nilotica). In The Birds of North America, No. 140 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia and The American Ornithologists' Union, Washington, D.C.
- 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.