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Gull-billed Tern (Gelochelidon nilotica) German name(s): "Lachseeschwalbe" Size: 33-42 cm; wing span 85-115 cm Body mass: 150-292 g Wing loading [g/cm2]: 0.30-0.35

Europe: Family Group 10 Family Group 10 Table Great Skua Arctic Skua Pomarine Skua Caspian Gull Great Black-backed Gull Lesser Black-backed Gull American Herring Gull European Herring Gull Yellow-legged Gull Audouin's Gull Slender-billed Gull Iceland Gull Common Gull Ring-billed Gull Black-headed Gull Bonaparte's Gull Mediterranean Gull Little Gull Sabine's Gull Black-legged Kittiwake Caspian Tern Sandwich Tern Gull-billed Tern Common Tern Arctic Tern Little Tern Forster's Tern Whiskered Tern Black Tern White-winged Black Tern Atlantic Puffin Razorbill Common Guillemot Black Guillemot Thumbnails page Family group table Index of bird names European birds home page

Similar species

Description     Classification     Distribution     Sightings     Photos     Breeding     Nest     Eggs     Behaviour     Food     Call/s

Physical description Click here for a physical description Gull-billed Terns are medium-sized terns. During the breeding breeding season they have a black cap, white front (throat, neck, chest, belly and vent) and grey wings. The black eyes are surrounded by the black cap, while the frons (base of the bill) is also black. The stout bill is black, the short legs and feet are also black. In eclipse the cap becomes mostly white, with grey patches remaining behind the eyes and some mottled black-and-white remaining at the back of the head. Juveniles are mottled grey, with a mottled cap and black eye patches. Twitcher's tip Compared to other, similar terns, the Gull-billed Tern has the most massive black bill (hence its name).

Taxonomy, classification See Gull-billed Tern at Wikipedia . Click here for classification information The Gull-billed Tern has been moved from the genus "Sterna" into "Gelochelidon". In addition, the Australian Tern has now been given full species status and is no longer considered to be race "macrotarsa" of the Gull-billed Tern.

Range, habitat, finding this species Click here for information on habitat and range The overall distribution of this species can be assessed, and specific locations where birds have been spotted can be found, based on individual sighting reports submitted by birdwatchers to ebird.org . The global distribution of the Gull-billed Tern is available HERE . Gull-billed Terns are a global species, of which there are 5 extant races. All races are dispersive after the end of the breeding season, and those breeding in the northern hemisphere are the most strongly migratory races. Nominate race "nilotica" have a very extended breeding range, from Europe and North Africa in the West, through the Middle East and southern-central Asia to western China and Thailand in the East. The breeding range of the Asian race "affinis" extends from parts of Indonesia (Borneo, Sulawesi, Sumatra) through the Philippines and south-eastern Asia, South and East China up to Japan in the East. The three other races, "aranea", "vanrossemi" and "gronvoldi" are found in various parts of the Americas (for details see, e.g., Wikipedia). The northern races tend to spend the winters farther South, e.g. in southern America, in Africa, or south-eastern Asia. Gull-billed Terns, nominate race "nilotica", are breeding migrants to Europe from the South. Apart from a few suitable locations inland, such as major rivers (e.g. Danube) or lakes (Lake Superior), they populate mostly coastal regions. They are found during their migration to the breeding grounds all around the Mediterranean Sea, but also along the Iberian and French Atlantic coastline, the coastlines of England and Wales, the North Sea coastline up to southern Scandinavia and parts of the coastline of the Baltic Sea. Gull-billed Terns can be found above coastal waters, but also in tidal flats and inland, in the shallows of freshwater lakes, including ephemeral lakes and ephemeral wetlands.

Sightings Click here for sighting information Race "nilotica" J. Pires reports finding Gull-billed Terns, nominate race "nilotica", regularly in the Tejo estuary, Portugal. In July 2019 a large flock was found at this location. The species was also found in Badajoz, Badajoz province, Spain, in July 2018. A. Sarok spotted a Gull-billed Tern, race "nilotica", in Vojvodina, Serbia, in the timeframe 2010-2024. More photos shown below were taken by M. Eaton in Egypt. Race "affinis" We have spotted Gull-billed Terns, race "affinis", in Australia.

Photos

Race "nilotica"

ADULT

Sex unknown

BREEDING

Lateral view of one of four Gull-billed Terns in breeding plumage (photo courtesy of J. Pires)
[Lagunas de Villafafila, Laguna de San Pedro, Zamora, Spain, April 2023]

Near-frontal view of a Gull-billed Tern in breeding plumage in flight (photo courtesy of J. Pires)
[Tejo estuary, Portugal, July 2019]

Near-frontal view of a Gull-billed Tern in breeding plumage in flight (photo courtesy of J. Pires)
[Tejo estuary, Portugal, July 2019]

Near-frontal/ventral view of a Gull-billed Tern in breeding plumage in flight (photo courtesy of J. Pires)
[Tejo estuary, Portugal, July 2019]

Lateral view of a Gull-billed Tern in breeding plumage in flight (photo courtesy of J. Pires)
[Tejo estuary, Portugal, July 2019]

Lateral view of a Gull-billed Tern in breeding plumage in flight (photo courtesy of J. Pires)
[Tejo estuary, Portugal, July 2019]

Lateral view of a Gull-billed Tern in breeding plumage in flight, wings up (photo courtesy of J. Pires)
[Tejo estuary, Portugal, July 2019]

Lateral/ventral view of a Gull-billed Tern in breeding plumage in flight issuing its call (photo courtesy of J. Pires)
[Tejo estuary, Portugal, August 2019]

Lateral/ventral view of a Gull-billed Tern in breeding plumage in flight (photo courtesy of A. Sarok)
[Vojvodina, Serbia, date unknown]

Near-dorsal/ventral view of a Gull-billed Tern in breeding plumage in flight (photo courtesy of J. Pires)
[Tejo estuary, Portugal, July 2019]

Gull-billed Terns in both breeding plumage (black caps) and non-breeding plumage (strong black bills, but white cap), on a roost together with other seabirds, primarily a flock of Black-headed Gulls (photo courtesy of M. Eaton)
[November 2017]

NON-BREEDING

Lateral view of a Gull-billed Tern in non-breeding plumage (photo courtesy of M. Eaton)
[November 2017]

Lateral view of a Gull-billed Tern in non-breeding plumage scooping something up from the water in flight (photo courtesy of J. Pires)
[Vila Franca de Xira, Tejo estuary, Portugal, August 2022]

Near-dorsal view of a Gull-billed Tern in non-breeding plumage in flight (photo courtesy of J. Pires)
[Tejo estuary, Portugal, August 2019]

IMMATURE/JUVENILE

Juveniles (the bird sitting highest and the one on the far right) as part of a small group of Gull-billed Terns
(photo courtesy of J. Pires)
[Badajoz, Badajoz province, Spain, July 2018]

Near-frontal view of two juvenile Gull-billed Terns issuing their calls (photo courtesy of J. Pires)
[Vila Franca de Xira, Tejo estuary, Portugal, August 2022]

Race "affinis"

Gull-billed Terns, race "affinis", were photographed by us in Australia.

Behaviour

Social behaviour: Communal

Mobility: Migratory

Elementary unit: Solitary/mob

Food, Diet

Like all terns, Gull-billed Terns feed on fish and other aquatic animals, which they catch with their bills just under the surface of water in a steep high-speed dive from considerable height.

Lateral view of one a Gull-billed Tern in breeding plumage with its prey, which looks like a cicada (photo courtesy of J. Pires)
[Vila Franca de Xira, Tejo estuary, Portugal, July 2024]

Gull-billed Tern in breeding plumage pouncing on its prey in a submerged rice paddy (photo courtesy of J. Pires)
[Tejo estuary, Portugal, July 2019]

Gull-billed Tern in breeding plumage about to take off with its prey, which looks like a grasshopper - in which case the bird is the farmer's "best friend" (photo courtesy of J. Pires)
[Tejo estuary, Portugal, July 2019]

Gull-billed Tern in breeding plumage defending its catch against a Black-headed Gull (photo courtesy of J. Pires)
[Tejo estuary, Portugal, August 2019]

Near-dorsal view of a Gull-billed Tern in breeding plumage taking off with its prey, possibly a prawn (photo courtesy of J. Pires)
[Tejo estuary, Portugal, July 2019]

Flock of about 100 Gull-billed Terns in breeding plumage hunting above a submerged rice paddy (photo courtesy of J. Pires)
[Tejo estuary, Portugal, July 2019]

Flock of about Gull-billed Terns in breeding plumage in a submerged rice paddy (photo courtesy of J. Pires)
[Tejo estuary, Portugal, July 2019]

Call(s)/Song

For this species we have recorded the following call(s)/song. The interpretation of their meaning is our own; comments and suggestions for improvement are welcome.

gbtern_jp_20240710.m4a

nilotica (Portugal)

Small mob hunting in a pack

© JP

More Gull-billed Tern sound recordings are available at xeno-canto.org .

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