Black Tern

Chlidonias niger

A black bodied tern that is easily identifiable in South Dakota, especially in its dark breeding plumage.  The bird at the right is an adult, breeding plumaged bird, with a black body and silvery-gray wings.  Non-breeding birds are much lighter in coloration, with white underparts and head, gray wings, and a small amount of black on the back of the head. Black Terns lead a unique life, nesting on freshwater marshes in the interior of North America, while wintering at sea around South America.  They gracefully pluck food items in flight from the surface of the water.  They will also chase flying insects, doing much of their foraging over aquatic habitats, but they will also forage over nearby terrestrial habitats.  As with some other gull and tern species, they will sometimes follow farm equipment to pursue insects that are stirred up.

Habitat: Marshes, ponds, lakes, flooded fields

Diet: Mostly insects and fish, also frogs and tadpoles, earthworms, and crustaceans. 

Behavior: Forages while in flight, dipping down to the water's surface to grab food, or also by catching insects in mid-air.

Nesting: June.  They breed in small colonies, sometimes associated with other species such as the Forster's Tern.  The nest is a mound of wetland vegetation with a slight depression on the top.  The female lays between 2 and 4 eggs, and both parents help to incubate them.  When the eggs hatch, both parents help tend to the yong.  The young fledge as soon as 3 weeks after hatching, but parents typically feed the young for another few weeks after fledging.

Breeding Map: Breeding Bird Survey Map

Song: Harsh kik-kik-kik-kik.

Migration: Summers in much of the northern Great Plains, the Great Lakes, and western U.S., as well as southern Canada.  Winters along northern coasts of South America.

Similar Species: Generally distinctive compared to other tern species in North America.  Very similar to the White-winged Tern, a Eurasian species that is a rare vagrant to North America.

Conservation Status: Populations have declined sharply in the past 40 years, likely due to drainage of wetlands required for nesting.  Farm chemical runoff is another possible reason.  Despite population declines, they are still found over a wide geographic area, and are common in some areas.  The IUCN lists the Black Tern as a species of "Least Concern".

Further Information: 1) USGS Patuxent Bird Identification InfoCenter, Black Tern

2) Cornell University's "All About Birds - Black Tern"

3) eNature.com -- Black Tern

Photo Information: May 14th, 2010 - Lake Whitewood in South Dakota -- Terry Sohl

Additional Photos: Click on the image chips or text links below for additional, higher-resolution Black Tern photos.