Common tern
Sterna hirundo
Daria Semenova · Poti, Samegrelo Georgia field photo
Key facts in one look
- Size
- 31–35 cm, wingspan 77–98 cm; 110–141 g
- Diet
- Small fish, crustaceans, molluscs, insects
- Status in Georgia
- Resident breeder, migrant, winter visitor
- Recorded regions
- Shida Kartli; Adjara; Kvemo Kartli
- Habitat
- Lakes, large rivers, sea coast, islands
- Family
- Laridae
- Conservation
- Global LC (2018); Georgia LC (2024)
The common tern catches fish by diving head-first from the air: it flies over the water with its bill pointed down, sometimes hovers in one spot, and then plunges straight in. It is 31–35 cm long, including a tail fork of 6–9 cm, with a wingspan of 77–98 cm, and weighs 110–141 g. It is pale grey above and almost white below, with a black cap, a red bill with a black tip and orange-red legs. It is harmless to people. If you see a red-billed, black-capped tern dropping into the water over a lake or the sea, it is most likely a common 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 April to September, with most in June and September. It is seen most often in Shida Kartli, at Nadarbazevi Lake, in Adjara, at the Chorokhi Delta, and in Kvemo Kartli. Both globally and in Georgia it is rated Least Concern (LC).
Identification
Common tern: how to identify it
In summer it has a pale grey back, an almost white belly, a black cap, a red bill with a black tip and orange-red legs. The tail is deeply forked, but on a perched bird it does not reach past the folded wingtips. In winter the forehead turns white and the bill turns black.
In breeding plumage it is pale grey above and very pale grey, almost white, below. It has a black cap, a red bill with a black tip and orange-red legs. The rump and tail are white. In the second half of summer a dark wedge appears on the wing as the old feathers wear.
In winter the forehead and underparts turn white, the bill becomes black or black with a red base, and the legs dark red or black. A dark bar shows along the front edge of the wing. Young birds have a ginger forehead and a ginger back with brown and white scaling.
It is easy to tell from the Sandwich tern, which is larger at 36–41 cm, with a black bill tipped yellow, black legs and a shaggy crest. The common tern's best-known call is a "kee-yah" alarm, stressed on the first syllable.
Colour
Swatches are illustrative. Do not identify a species by colour alone.
Often confused with
It breeds in a wider range of places than any of its relatives. For a nest it picks a flat, sparsely vegetated spot close to water: a sand or shingle shore, an island, a lake shore, a gravel bar in a river or a gravel pit. It readily takes to artificial floating rafts. It breeds from sea level to high mountains, up to 2000 m in Armenia. Outside the breeding season it needs only water rich in fish nearby and somewhere to land, such as a shore, a post or a pier. In Georgia most records come from Shida Kartli, from Nadarbazevi Lake and Gori Municipality, from May to July. In Adjara it is seen mainly in the Chorokhi Delta and near Batumi, in September. In Kvemo Kartli the records come from near Rustavi, Gardabani Municipality and Kumisi Lake, from April to July. There are single records from the coast at Poti and Khobi, from Dusheti and Mtskheta municipalities, from Ninotsminda Municipality and from Tbilisi.
The common 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. Three regions have enough records: Shida Kartli, Adjara and Kvemo Kartli.
Data: Reptiles.ge + iNaturalist · Methodology
- Field observation
- Several records in one spot
- Photo record
- Region with records
It eats mainly small fish, which it catches in the sea, in lakes and in large rivers. It drops into the water from the air and goes under for a second, but not deep. In some places invertebrates make up a large part of its diet: worms, leeches, molluscs and crustaceans such as shrimps. Near fresh water it also catches large insects, beetles and moths, sometimes in the air. It often hunts in flocks when fish are plentiful.
It is a strong migrant. Palearctic breeders head south after breeding, between August and October, and return in March or April. European birds winter mostly off the coasts of western and southern Africa. One bird ringed at its nest in Sweden was found five months later in New Zealand, about 25,000 km away. It breeds in colonies, usually of up to 2,000 pairs, sometimes together with other terns and black-headed gulls. The nest is a scrape in sand or shingle, often lined with whatever debris is at hand. Eggs are laid mainly in early May, usually 3. Both parents incubate for 21–22 days, and the chicks start to fly at 22–28 days. It usually forages 5–10 km from the colony, sometimes up to 15 km. It defends its nest fiercely: it dives at people and dogs, though it rarely strikes and usually swerves away at the last moment. In the wild it typically lives 12 years, and the oldest known bird in Europe was 33.
Globally the common tern is rated Least Concern (LC, 2018). A 2015 estimate puts the population at about 1,600,000–3,600,000 birds. The overall trend is unclear: numbers are rising in Europe, while in North America they fell by about 70% over 40 years. When breeding it is threatened by human disturbance at colonies, from vehicles, boats, recreation and dogs, and by rising water that floods the nests. In the past, egg collecting, hunting and the feather trade for hats cut its numbers sharply. In some places, such as parts of West Africa, hunting is still a serious problem. The species 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.
Daria Semenova · Joey Devine · Nathaniel Sharp · tomo_m · Anna Shipilova · Zac Cota · Nikita Tiunov
Related guides
Continue with related pages
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 April to September, with most in June and September.
Most often at Nadarbazevi Lake, from May to July, and in the Chorokhi Delta, in September. In Kvemo Kartli it is seen near Rustavi, in Gardabani Municipality and at Kumisi Lake. Look for it over lakes, large rivers and the sea, where it drops into the water.
In summer it is pale grey, with a black cap, a red bill with a black tip and orange-red legs. The tail is deeply forked. The Sandwich tern is larger, with a black bill tipped yellow and black legs.
It is 31–35 cm long, including the tail fork, with a wingspan of 77–98 cm, and weighs 110–141 g.
Mainly small fish, which it catches by diving into the water from the air. In some places it also eats shrimps, molluscs, worms and large insects.
In colonies, close to water, on a flat, sparsely vegetated spot: a sand or shingle shore, an island or a floating raft. The nest is a scrape in the ground. It usually lays 3 eggs, both parents incubate for 21–22 days, and the chicks start to fly at 22–28 days.
It is harmless to people, though it dives at anyone who comes close to a colony. Both globally and in Georgia it is rated Least Concern (LC). Disturbance at breeding sites and flooded nests 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.
