Sandwich tern
Thalasseus sandvicensis
José Antonio Linage Espinosa · Progreso
Key facts in one look
- Size
- 36–41 cm, wingspan 95–105 cm; 200–300 g
- Diet
- Marine fish, shrimps, marine worms
- Status in Georgia
- Resident breeder, migrant, winter visitor
- Recorded regions
- Adjara; Abkhazia; Samegrelo-Zemo Svaneti; Guria
- Habitat
- Sea coast, deltas, estuaries, bays
- Family
- Laridae
- Conservation
- Global LC (2019); Georgia LC (2024)
In Georgian the Sandwich tern is named for its bill: it is black with a yellow tip. It is a large tern, 36–41 cm long with a wingspan of 95–105 cm, and weighs 200–300 g. It is silvery grey above and white below, with a black cap and a shaggy crest at the back, and short black legs. In flight it looks very pale. It is harmless to people. If you see a large, almost white tern over the sea, calling loudly and harshly and plunging into the water, it may well be a Sandwich tern. The 2024 Georgian checklist lists it as a resident breeder, a migrant and a winter visitor, although its seasonal pattern in Georgia is not fully understood. Records run from January to October, with most in September and May. Almost all records come from the Black Sea coast: Adjara, Abkhazia, Samegrelo and Guria. Both globally and in Georgia it is rated Least Concern (LC).
Identification
Sandwich tern: how to identify it
It is a large, very pale tern. Its thin black bill with a yellow tip, black legs and shaggy black crest at the back of the head set it apart. In winter the forehead turns white.
It is pale silvery grey above and white below. The bill is thin, sharp and black, with a yellow tip. The legs are short and black. In summer it has a black cap that runs into a shaggy crest at the back.
At the end of summer, in July and August, it moults and the forehead turns white. It regains the black forehead in February and March. Young birds have an all-black bill without the yellow tip, a scaly back and wings, and dark tips to the tail.
The common tern is smaller, 31–35 cm, with a red bill tipped black and orange-red legs. The Sandwich tern is very noisy: its call is a loud, grating "kerr-ick".
Colour
Swatches are illustrative. Do not identify a species by colour alone.
Often confused with
It is a seabird. It breeds on sea coasts and islands, on sandy islands, sand spits, dunes, shingle beaches and large deltas with clear, shallow water rich in fish close by. It breeds inland only exceptionally, on large lakes near the coast. Outside the breeding season it is seen on sandy and rocky beaches, mudflats, estuaries, harbours and bays, and often feeds out at sea. In Georgia most records come from Adjara, from the Chorokhi Delta and Batumi, mainly in September. In Abkhazia it is seen near Sukhumi, Gulripshi, Gudauta, Ochamchire and Gagra, in winter too. In Samegrelo-Zemo Svaneti and Guria the records come from the coast at Poti, Shekvetili and Grigoleti. Away from the sea there are a few records from the Tbilisi Sea, in May and July.
The Sandwich 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. Four regions have enough records: Adjara, Abkhazia, Samegrelo-Zemo Svaneti and Guria.
Data: Reptiles.ge + iNaturalist · Methodology
- Field observation
- Several records in one spot
- Photo record
- Region with records
It catches fish by diving into the water from the air, almost always at sea. It usually plunges straight in, without much hovering. It eats mainly marine fish 9–15 cm long that live near the surface, as well as small shrimps and marine worms.
It is a long-distance migrant. After breeding it first disperses to rich feeding grounds, both north and south, and then flies south. Different populations winter in different places: birds that breed on the Caspian coast go to the Indian subcontinent, as far as Sri Lanka. It is sociable all year and often feeds in flocks where fish are plentiful. It breeds from May to July in very dense colonies, where neighbouring nests are only 20–30 cm apart. It often nests together with other terns and black-headed gulls. The nest is a scrape in the ground. The female lays 1–2, rarely 3 eggs. Both parents incubate for about 24 days. The chicks leave the nest after 2 days and become independent at 4–5 weeks. It lives up to 23 years. In courtship the male offers the female a fish.
Globally the Sandwich tern is rated Least Concern (LC, 2019). A 2015 estimate puts the population at 490,000–640,000 birds, or about 325,000–430,000 mature individuals. The overall number is stable, though it fluctuates. Because there are only a few colonies each year, it is highly vulnerable to human disturbance. In some places egg collecting and hunting reduce its numbers. In 2022 avian influenza caused mass deaths in many colonies in north-western Europe, more often among older, experienced birds. The species is listed in Appendix II of the Bern Convention and is covered by the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA). The 2024 Georgian checklist also rates it Least Concern (LC) in Georgia.
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Yes. The 2024 Georgian checklist lists it as a resident breeder, a migrant and a winter visitor, although its seasonal pattern is not fully understood. Records run from January to October, with most in September and May.
On the Black Sea coast. Most records come from the Chorokhi Delta and Batumi, mainly in September. It is also seen near Poti, Shekvetili and Grigoleti, and near Sukhumi and Gagra. There are a few records from the Tbilisi Sea too.
It is a large, very pale tern with a black bill tipped yellow, black legs and a shaggy black crest at the back of the head. Its call is a loud, grating "kerr-ick". The common tern has a red bill and red legs.
It is 36–41 cm long, with a wingspan of 95–105 cm, and weighs 200–300 g. Males are on average slightly heavier than females.
Mainly marine fish 9–15 cm long that live near the surface, which it catches by diving in from the air. It also eats small shrimps and marine worms.
On sea coasts and islands, in very dense colonies, from May to July. The nest is a scrape in the ground. The female lays 1–2, rarely 3 eggs, and both parents incubate for about 24 days.
It is harmless to people. Both globally and in Georgia it is rated Least Concern (LC). Disturbance at colonies, egg collecting and avian influenza threaten it. 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.
