Interior Least Tern (Sterna antillarum)
(Federally listed as Endangered)
Description: The Least Tern is the smallest North American
member of the gull and tern family. The Least Tern it is a
slender, streamlined bird with a white breast and belly, a gray
back and long, narrow, pointed wings. It has a forked tail and a
straight, pointed beak that is usually a deep yellow color.
Least Terns feed on small fish that they catch near the surface
of the water.
Habitat: Terns live along large rivers and may sometimes be
found hunting fish in shallow wetlands and the margins of ponds
and lakes. Least Terns require bare sand and gravel for nesting
and typically nest in small colonies consisting of two to 20
pairs along large rivers on sand bars and scoured bends.
Colonies also occur on salt flats such as the large one at Salt
Plains National Wildlife Refuge.
Current and Historic Distribution: The Least Tern is a rare
species and is found in Oklahoma during the late spring and
summer breeding season (mid-May through late August). In
Oklahoma, Least Terns may be found on portions of the Arkansas,
Cimarron, Canadian and Red rivers. Outside of Oklahoma, Least
Terns occur along the Atlantic and Gulf coasts of the U.S., as
well as on several wide, sandy rivers in Great Plains such as
the Missouri, Platte and Yellowstone. In the fall, all Least
Terns migrate south to spend the winter in the Caribbean and the
northern coast of South America.
Reasons for Decline: Widespread loss and alteration of its
riverine nesting habitat has eliminated the Least Tern from many
locations within its former breeding range in the interior U.S.
The construction of large reservoirs has permanently submerged
some nesting areas and has altered the season flooding dynamics
that are required to build and sustain the sandbars that the
terns need for nesting. Additionally, recreational vehicle use
and other disturbances around nesting colonies has reduced
nesting success and reproduction.
County by County List of Endangered and Threatened Species
US Fish and Wildlife Endangered Species Lists