Nepedia
Back to Discover
Fluent Reader
🧬

Tern

life science Maturity 7-9 Next article →

Terns are graceful seabirds found in almost every part of the world.

Birds of Sweden 2016 07
Birds of Sweden 2016 07

You can find them near the ocean, along rivers, or in wetlands. These birds belong to a group called Sterninae. This group is part of a larger family called Laridae.

Birds of Sweden 2016 08
Birds of Sweden 2016 08

This same family also includes many types of gulls and skimmers. Terns are very important because they are skilled hunters of fish. Most species are currently facing hard jobs to survive. They deal with lost homes, pollution, and new predators. Some, like the Chinese crested tern, are critically endangered.

Terns have a very specific way of looking and moving. They are slender and lightly built with long, narrow wings. Their tails are often deeply forked, which helps them look elegant in flight.

Sterna hirundo -Nantucket National Wildlife Refuge, Massachusetts, USA -adult and juvenile-8
Sterna hirundo -Nantucket National Wildlife Refuge, Massachusetts, USA -adult and juvenile-8

Most adults have pale grey feathers on top and white feathers below. They often wear a black cap on their heads. This white belly helps them hide from fish when they look up from below. This is a way to stay hidden while they hunt. Some species, like the Inca tern, have much darker feathers instead.

Larosterna inca4
Larosterna inca4

People have known about these birds for a very long time. The word "stearn" was used in Old English as early as the eighth century.

White tern with fish
White tern with fish

Scientists have worked for years to understand how they are related to other birds. A famous scientist named Linnaeus helped name them in 1758. He used the name Sterna for them. He called them "rostrum subulatum," which means they have an awl-shaped bill. This refers to their long, pointed bills that look like a sharp tool. This helps them tell them apart from gulls with thicker bills.

Terns come in many different sizes and shapes. The least tern is very small, weighing only about 33 grams.

Yellow-billed tern Sternula superciliaris
Yellow-billed tern Sternula superciliaris

On the other end, the Caspian tern can reach 1.5 kilograms.

Sterna-caspia-010
Sterna-caspia-010

They use many different sounds to talk to each other. A common tern makes a "kee-yah" sound to warn others of danger.

Gull-billed Tern in Koonthalulam, India, by Dr. Tejinder Singh Rawal
Gull-billed Tern in Koonthalulam, India, by Dr. Tejinder Singh Rawal

They also use a "kip" sound when they are being social. Parents and chicks use these calls to find one another. Even siblings can recognize each other's voices after twelve days.

You can think of a tern's life as a series of changes. When they are young, their feathers look scaly with dark edges.

Sterna hirundo -Nantucket National Wildlife Refuge, Massachusetts, USA -adult and juvenile-8
Sterna hirundo -Nantucket National Wildlife Refuge, Massachusetts, USA -adult and juvenile-8

They do not look like adults until they are about three years old. Terns also change their clothes, or plumage, after the breeding season. They grow a white forehead for the winter.

Chlidonias niger
Chlidonias niger

This is a bit like how we change our clothes for different weather. Their life in the air and sea is a constant cycle of growing and moving.

443 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (20)
File:Birds of Sweden 2016 07.jpg
Birds of Sweden 2016 07.jpg
File:Birds of Sweden 2016 08.jpg
Birds of Sweden 2016 08.jpg
File:Larosterna inca4.jpg
Larosterna inca4.jpg
File:White tern with fish.jpg
White tern with fish.jpg
File:Anous minutus by Gregg Yan 02.jpg
Anous minutus by Gregg Yan 02.jpg
File:Sterna fuscata.JPG
Sterna fuscata.JPG
File:Yellow-billed tern Sternula superciliaris.jpg
Yellow-billed tern Sternula superciliaris.jpg
File:Large-billed Tern (Phaetusa simplex), Pantanal, Brazil.jpg
Large-billed Tern (Phaetusa simplex),...
File:Sterna-caspia-010.jpg
Sterna-caspia-010.jpg
File:Gull-billed Tern in Koonthalulam, India, by Dr. Tejinder Singh Rawal.jpg
Gull-billed Tern in Koonthalulam, India,...
File:Larosterna inca3.jpg
Larosterna inca3.jpg
File:White-winged Tern, Mścichy, Biebrzański Park Narodowy, Polska.jpg
White-winged Tern, Mścichy, Biebrzański...

+ 8 more

More to explore

✨ What else?

Related topics you might enjoy

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.