A Tern Fact File

Sterna anaethetus

Bridled tern (Sterna anaethethus)

Black beak and feet. Head, neck, breast and underbelly are mostly white. Black from face to back of head. White stripe runs over eyebrow area; black stripes run backward across eyes. Dark grayish-brown back. During flight: Tops of wing feathers and outer ends of tail feathers are white. White feathers underneath wing. Dark gray primary and secondary flight feathers. Young: Similar to adults, but feathers more lightly pigmented. White face and forehead. Light brown back. Usually appear among rocky cliffs on islands.

Day in and day out, the little tern laboriously incubates her egg, waiting for her baby to come into the world. （photo by Liu Yen-ming）

Sterna albifrons

Little tern (Sterna albifrons) Summer markings: Yellow beak with black tip, orangish-yellow feet. White head, neck, breast and underbelly. Black stripes run from face to back of neck and backward across eyes. Gray back. During flight: Undersides of wings are white, except primary flight feathers, whose outer portions are grayish-black. White feathers underneath tail. White tail feathers. Tail is forked. Winter markings: Similar to summer, but beak is black, feet are dark brown. Black stripe on head diminished, covering only top of head down to nape of neck. Young: Similar to adults' winter markings, but brown spots cover top of head, nape of neck and back. During flight: Black primary flight feathers, white secondary flight feathers. Short, white tail, tip covered with brown spots. Usually appear along seacoasts, river mouths, marshes and fish ponds. A minority are perennial residents of Taiwan.

Sterna dougallii The baby roseate tern huddles in its nest, waiting for Mama to bring back some little fish.

Sterna sumatrana

Black-naped tern (Sterna sumatrana)

Back beak and feet. White head, neck, breast and underbelly. Black stripes run backward across eyes; back of head is black. Light gray back. White feathers underneath and on top of tail, middle layer black. Most often seen along coasts and islands, most common around small offshore islands.

Roseate tern (Sterna dougallii)

Summer markings: Dark red beak with black tip. Red feet. White head, neck, breast and underbelly. Top of head is black, back light gray. When stationary, tail feathers appear longer than wing feathers. During flight: White feathers underneath tail. White tail feathers. Winter markings: Similar to summer, but beak is black, feet dark brown. From forehead to top of head is white. Black stripe runs lengthwise along top of head. Usually seen on land along seacoasts, reefs and islands.

Anous stolidus

It's hard to believe that in five weeks this unimpressive little bird will open its wings and fly.

Brown noddy (Anous stolidus)

Black beak and feet. Dark brown body. White face and forehead. Top to back of head light violet-gray. Thin, semi-circular line under eyes. During flight: Tip of tail parts in two. Appear among rocky cliffs on seacoasts and islands.

[Picture Caption]

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This freshly mature bridled tern has still not lost its naivete. It's extremely curious about its surroundings.

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This adolescent bridled tern has a youthful look about it.

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Day in and day out, the little tern laboriously incubates her egg, waiting for her baby to come into the world. (photo by Liu Yen-ming)

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It's hard to believe that in five weeks this unimpressive little bird will open its wings and fly.

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If you don't look closely, you probably won't notice that a family of three brown noddies is living here.

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The baby roseate tern huddles in its nest, waiting for Mama to bring back some little fish.

If you don't look closely, you probably won't notice that a family of three brown noddies is living here.