Overview
The California least tern is the smallest of the tern species. By the 1960s, its habitat availability had been severely reduced due primarily to coastal development and intense human recreational use of beaches. As a result, population numbers for the species have diminished from uncountable thousands to several hundred by 1970, when the species was listed as endangered.
Scientific Name
Identification Numbers
Characteristics
Physical Characteristics
California least terns measure fewer than 10 inches in length, with a total wing length of approximately 4 inches.
California least terns weigh between 45 and 55 grams.
This subspecies has a short, forked tail, and a long, slightly decurved, tapered bill. Males and females are both characterized by a black cap, gray wings with black wingtips, white underbody, orange legs and a black-tipped yellow bill.
Life Cycle
California least terns are present in the United States during the breeding season, which extends from mid-April to mid-September. They nest in colonies of typically 15 to 300 pairs.
Food
California least terns forage in nearshore waters, estuaries and river mouths for slender-bodied fish such as anchovies and topsmelt.
Habitat
California least terns nest on 23 sites, some of which are natural and others are man-made and include beaches close to river mouths, estuaries and coastal embayments. These sites require active management activities, including protection from disturbance and predators, and or, vegetation management to retain habitat suitability.
The land near a shore.
Geography
The least tern breeds along the Pacific coast from San Pablo Bay, California, in the north, to San Jose del Cabo, in the state of Baja California Sur, Mexico, to the south.
Timeline
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