Gull-billed tern
Gelochelidon nilotica
ibhappy · Tijuana Slough National Wildlife Refuge
Key facts in one look
- Size
- 33–42 cm, wingspan 76–91 cm; 150–292 g
- Diet
- Insects, spiders, frogs, small reptiles, small fish
- Status in Georgia
- Migrant, winter visitor
- Recorded regions
- Kvemo Kartli; Shida Kartli
- Habitat
- Lakes, marshes, lagoons, wet fields
- Family
- Laridae
- Conservation
- Global LC (2019); Georgia LC (2024)
Unlike many other terns, the gull-billed tern does not normally plunge into the water for fish: it catches mostly insects in the air and often hunts over wet fields. It is 33–42 cm long, with a wingspan of 76–91 cm, and weighs 150–292 g. In summer it is grey above and white below, with a black cap and a black bill and legs. The short, thick bill, broad wings, long legs and robust body set it apart from other terns. It is harmless to people. The 2024 Georgian checklist lists it as a migrant and a winter visitor. In Georgia it is seen mainly from April to July, most often in April and May. Most records come from Kvemo Kartli, from Kumisi Lake and the Tbilisi Sea, and from Shida Kartli, at Nadarbazevi Lake. Both globally and in Georgia it is rated Least Concern (LC).
Identification
Gull-billed tern: how to identify it
The key feature is the short, thick, gull-like black bill. In summer it has a black cap; in winter the cap disappears and a dark patch remains through the eye. In size and general appearance it resembles the Sandwich tern.
In breeding plumage it is grey above and white below, with a black cap. The bill is short, thick, gull-like and black, and the legs long and black.
It is 33–42 cm long, with a wingspan of 76–91 cm, and weighs 150–292 g. In size and appearance it resembles a Sandwich tern, but differs in its short, thick bill, broad wings, long legs and robust body. The call is a characteristic "ker-wik".
In winter the black cap disappears and a dark patch remains through the eye. Young birds have a fainter patch and otherwise look like winter adults. Young Sandwich terns have short bills and are often mistaken for gull-billed terns.
Colour
Swatches are illustrative. Do not identify a species by colour alone.
Often confused with
It breeds on bare or sparsely vegetated islands, banks and flats of dry mud and sand: coastal sand shoals, dunes, salt marshes, salt pans, freshwater lagoons, estuaries, deltas, inland lakes, rivers and marshes. When breeding it also hunts over lakes, farmland, grassland and semi-desert. On migration it stops at salt lakes, coastal lagoons, mudflats, marshes and wet fields. In Georgia most records come from Kvemo Kartli: from Kumisi Lake, the Tbilisi Sea and Gardabani Municipality. In Shida Kartli it is often seen at Nadarbazevi Lake. There are single records from Bazaleti Lake, Lanchkhuti Municipality, Batumi, Akhalkalaki and Ninotsminda municipalities, Sagarejo and Lagodekhi municipalities, and Gagra.
The gull-billed tern map combines public iNaturalist observations. Regions are taken from the records-by-region table, and the status column separates regions with enough records from regions with too few records. Record counts reflect observation effort rather than population density. Two regions have enough records: Kvemo Kartli and Shida Kartli.
Data: Reptiles.ge + iNaturalist · Methodology
- Field observation
- Several records in one spot
- Photo record
- Region with records
It has a broader diet than most terns and takes whatever it can catch. It eats mainly insects, adults and larvae, from land and water: mayflies, dragonflies, moths and beetles. It also takes spiders, earthworms, small reptiles, frogs, fish 6–9 cm long and aquatic invertebrates, and rarely voles and small birds. It catches insects mainly in the air and also hunts over wet fields and scrub.
Northern populations are migratory: after breeding they disperse widely and then fly south to Africa, southern Asia, the Caribbean and northern South America. It stays in groups outside the breeding season too. It breeds in colonies of its own species of 5–500 pairs, occasionally up to 1,000, or as single pairs in colonies of other species. The nest is a scrape in dry mud, sand or gravel: on beaches, dry mudflats, dykes, sea-wrack on the tideline, sometimes on floating vegetation. The female lays 2–5 eggs. After breeding it leaves the colony early.
Globally the gull-billed tern is rated Least Concern (LC, 2019). Together with the Australian species, Gelochelidon macrotarsa, its numbers were estimated at 150,000–420,000 birds. Since the split it has not been estimated on its own. Europe holds 16,600–21,200 pairs. Worldwide its numbers are probably falling, because of habitat loss and degradation in the core of its range, while in Europe they are increasing. It readily abandons breeding sites when disturbed by people. The Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies to it. The 2024 Georgian checklist also rates it Least Concern (LC) in Georgia.
Related guides
Continue with related pages
Yes. The 2024 Georgian checklist lists it as a migrant and a winter visitor. It is seen mainly from April to July, most often in April and May.
Most records come from Kumisi Lake, the Tbilisi Sea and Nadarbazevi Lake. It has also been seen at Bazaleti Lake, in Lanchkhuti Municipality and near Batumi. Look for it over lakes and wet fields.
By its short, thick, gull-like black bill, black legs, grey back and white belly. In summer it has a black cap, in winter a dark patch through the eye. The call is "ker-wik".
They are similar in size and appearance, but the gull-billed tern has a short, thick bill, broad wings, long legs and a robust body. Young Sandwich terns also have short bills, so the two are often confused.
Mainly insects, which it catches in the air. It also eats spiders, earthworms, small reptiles, frogs and small fish, and rarely voles and small birds. It also hunts over wet fields.
In colonies of 5–500 pairs, or as single pairs in colonies of other species. The nest is a scrape in dry mud, sand or gravel. The female lays 2–5 eggs.
It is harmless to people. Both globally and in Georgia it is rated Least Concern (LC), although its world numbers are probably falling. It readily abandons breeding sites when disturbed. If you find an injured bird, call 112 or the environmental protection service.
References
What this profile is based on
Species profiles are compiled from peer-reviewed literature and established biodiversity databases, and are reviewed as new taxonomic and conservation data become available.
Prepared by the Reptiles.ge editorial team from the sources listed here.
