Chlidonias niger

Physical characteristics: Black terns have black heads, necks, and breasts. Their backs and bellies are dark gray in color. Juveniles and nonbreeding adults are pale gray on the back and white on the belly and head, with a dark patch on the side of the breast.

Geographic range: Black terns are found in temperate North America, Europe, and Eastern Asia during the breeding season. They spend the winter in Central and South America and in Africa.

Habitat: Black terns breed in inland habitats such as ponds, lakes, and marshes. In the winter, they occupy seashore and coastal wetland habitats.

Diet: Black terns eat aquatic insects, snails, small fish, tadpoles, and frogs.

Behavior and reproduction: Black terns breed in small colonies, generally fewer than twenty individuals, although colonies of as many as a hundred birds have been seen. A single male mates with a single female, and both parents help incubate, sit on, the eggs as well as take care of young. The black tern nest is usually built on top of

The black tern nest is usually built on top of floating vegetation. Both parents help incubate, sit on, the eggs as well as take care of young. (© John Mitchell/Photo Researchers, Inc. Reproduced by permission.)

floating vegetation. The female lays two to three eggs at a time, and these hatch after twenty to twenty-three days. Chicks leave the nest after twenty-five days.

Black terns and people: The preferred nesting areas of black terns include the small lakes or marshes that are often drained by humans.

Conservation status: Black terns are not considered threatened. However, some populations have declined due to destruction of wetland habitats, pesticides, and competition with human-introduced fish for food.

FOR MORE INFORMATION Books:

del Hoyo, J., A. Elliott, and J. Sargatal, eds. Handbook of the Birds of the World. Vol. 3, Hoatzin to Auks. Barcelona: Lynx Edicions, 1996.

Perrins, Christopher, ed. Firefly Encyclopedia of Birds. Buffalo, NY: Firefly Books, 2003.

Web sites:

"Family Laridae (Gulls and Terns)." Animal Diversity Web, The University of Michigan Museum of Zoology. http://animaldiversity.ummz.umich. edu/site/accounts/classification/Laridae.html#Laridae (accessed on June 1, 2004).

"Family Rynchopidae (Skimmers)." Animal Diversity Web, The University of Michigan Museum of Zoology. http://animaldiversity.ummz.umich. edu/site/accounts/classification/Rynchopidae.html#Rynchopidae (accessed on June 1, 2004).

"Laridae (Gulls)." The Internet Bird Collection. http://www.hbw.com/ibc/ phtml/familia.phtml?idFamilia=66 (accessed on June 1, 2004).

"Rynchopidae (Skimmers)." The Internet Bird Collection. http://www.hbw.com/ibc/phtml/familia.phtml?idFamilia=68 (accessed on June 1, 2004).

"Sternidae (Terns)." The Internet Bird Collection. http://www.hbw.com/ ibc/phtml/familia.phtml?idFamilia=67 (accessed on June 1, 2004).

AUKS, PUFFINS, AND MURRES Alcidae

Class: Aves

Order: Charadriiformes

Family: Alcidae

Number of species: 23 species

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