The Interior Least Tern is a state and federally protected endangered species. It is the smallest tern in North America. The Interior Least Tern is an energetic, swallow-like bird with a deeply forked tail and slender wings. They are graceful, agile flyers and are often observed hovering over bodies of water and diving to catch small fish.

Interior Least Terns are:

  • slightly smaller than a robin
  • 9 inches long from beak to tail
  • 20 inches from wing tip to wing tip

Appearance

Breeding Adult
white body
black cap with white forehead
light gray wings
yellow bill with black tip
yellow-orange legs

 

Winter Adult
paler than breeding birds
dark grey eye strip
white forehead with dusky brown cap
brownish-black bill
pale yellow legs

 

Juvenile (1 years old)
closely resembles winter adult
mottled gray-white body
white forehead with dusky brown cap
dark bill
orange-black legs
Breeding adult Interior Least Tern
Breeding adult Interior Least Tern

 

Juvenile Interior Least Tern
Juvenile Interior Least Tern

Vocalization

Sound byte Courtesy of The Macaulay Library at the Cornell Lab of Ornithology, Ithaca, New York. Recordist: Charles A. Sutherland.