Image: Chris van Rooyen
Common names: White-winged Tern, White-winged Black Tern (Eng.); witvlerksterretjie (Afr.); witvleugelstern (Dutch); guifette leucoptère (French); Weißflügel-seeschwalbe (German); gaivina-d’asa-branca (Portuguese)
Description/How to recognise a…
A White-winged Tern is a small gull-like bird around 23–27 cm in length, with a wingspan of 63–67 cm and weighs around 54–66 g. Summer breeding adults are characterised by a black head, neck and belly that is contrasted by a white rump. The upper parts of wings, as the name implies, are mostly white, while the black underwing coverts are diagnostic for breeding adults of the species. The bill/beak is reddish-black and the feet are red. In non-breeding adults and the similar-looking juveniles, most of the black feathers are replaced by white and greyish-brown patches, including ‘earmuff’ patches on the head. The coloration of non-breeding adults is sometimes confused with other terns, with upper parts pale grey and a white head and underparts. They may retain some black underwing coverts in winter.
Getting around
The White-winged Tern flies about with wing beats that can be best be described as shallow and leisurely. When hunting they can be seen flying slowly above the water to catch insects in flight or dipping down to catch prey on the water’s surface. They may also be seen on occasion dipping slightly below the surface.
Communicating
When alarmed, the White-winged Tern makes a short, loud ‘kek-kek’ bird sound.
Distribution
White-winged Terns have an extremely large distribution range encompassing the Afrotropical, Indomalayan, Nearctic, Neotropical, Oceanic and Palearctic realms. Breeding populations can be found from China to central Europe. Non-breeding populations are found in southeast Asia, northern Australia and most of sub-Saharan Africa. The southern African distribution includes southern Mozambique, Zimbabwe, northern and southeastern Botswana, central and northern Namibia and central and southwestern South Africa. They are extant (native, non-breeding) to South Africa, where they occur in the central and southwestern parts of the country.
Habitat
During the breeding season, White-winged Terns can be found near freshwater lakes, ponds and swamps with extensive emergent or fringing vegetation. Winter migrating birds are commonly found in habitats such as open lakes and rocky coasts, estuaries, coastal lagoons and mangrove swamps. Southern African populations frequent wetlands, dams, riverine forests and moist grasslands. Usually found near freshwater marshes.
Food
The bird’s diet mainly consists of invertebrates and small fish, but they also feeds on crabs, shrimp and other aquatic animals. When feeding on flying insects, they forage in flocks and use the wind to carry them upwards to catch their prey. When feeding on aquatic prey, they perform an arial attack, plunging down to the water’s surface to seize its prey. Prey are taken to a secluded area to be killed and eaten. They are also opportunistic and will eat fish discarded by fishing boats.
SEX and LIFE CYCLES
Sex: The breeding season occurs between April and August (spring to summer), but predominantly in June. They usually lay three eggs, which are incubated for 20 days, and the hatchlings fledge after 24 days. The nesting site consists of a shallow cup in a mound of aquatic vegetation placed over water on floating mats of vegetation, or on dry shores or resting on the bottom in shallow water.
Family life: This bird is usually seen in small family groups or in large flocks. They may either nest in single- or mixed-species colonies.
THE BIG PICTURE
Friends and Foes
They have been recorded to be preyed on by Falco peregrinus (Peregrine Falcon).
Smart Strategies
White-winged Terns are able to make extensive use of artificial wetlands such as sewage works and salt pans as a habitat
Poorer world without me
Birds of the Laridae family play an important role in aquatic ecosystems.
People & I
There has been one recorded case by Airports Company of South Africa (ACSA)’s bird strike avoidance service in collaboration with SANBI’s Genetic Services Unit’s DNA barcoding or ‘bird strike service’, of a White-winged Tern being involved in a collision with a Mango aeroplane on landing.
Conservation status and what the future holds
The current population is stable, but they are threatened by habitat destruction and drainage of wetlands in Europe. However, due to large population size and extensive range they are not considered under threat. The IUCN Red List global assessment lists them as Least Concern.
RELATIVES
The White-winged Tern belongs to the genus Chlidonias. The genus contains four species, the White-winged Tern (Chlidonias leucopterus), Black Tern (Chlidonias niger), Whiskered Tern (Chlidonias hybrida) and the Black-fronted Tern (Chlidonias albostriatus). Hybridisation of the White-winged Tern and Black Tern has been recorded in Sweden and the Netherlands. Hybrids show a combination of characters including the dark mantle of the White-winged Tern and the dark patches on the breast side of the Black Tern.
Official Common Name: White-winged tern
Scientific Name and Classification:
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Charadriiformes
Family: Laridae
Genus: Chlidonias
Species: C. leucopterus (Temminck, 1815)
Derivation of scientific name: The genus name, Chlidonias is derived from the Ancient Greek word for ‘swallow-like’.
References and further reading
- BirdLife International, 2021, Species factsheet: Chlidonias leucopterus, http://www.birdlife.org, accessed: 24/03/2021.
- BirdLife International, 2016, Chlidonias leucopterus. The IUCN Red List of Threatened Species 2016: e.T22694782A86772583, https://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22694782A86772583.en.
- Bouglouan, N., undated, White-winged Tern Chlidonias leucopterus, http://www.oiseaux-birds.com/card-white-winged-tern.html, accessed: 24/03/2021.
- Davis, A.H., 1982, ‘Terns showing mixed characters of Black and White-winged BlackTern’, British Birds 75(12): 579–580
- Hockey, P.A.R., Dean, W.R.J., Ryan, P.G. & Maree, S., 2005, Roberts’ Birds of Southern Africa 5th edition, Bird Book Fund, Cape Town.
- Iziko Museums of South Africa, undated, Chlidonias leucopterus (White-winged tern), https://www.biodiversityexplorer.info/birds/laridae/chlidonias_leucopterus.htm, accessed: 24/03/2021.
- Nord University, 2020, White-winged Tern (Chlidonias leucopterus), https://www.birdid.no/bird/eBook.php?specieID=1329, accessed: 24/03/2021.
- Vinicombe, K., 1980, ‘Tern showing mixed characters of Black Tern and White-winged Black Tern’ British Birds 73(5): 223–225
Author: Janine Baxter, Monica Mwale