Listed as endangered. "Endangered" means that a species is in danger of dying out.
We now think the tern should be listed as "threatened." That would mean we are concerned about it but we don't think it is about to go extinct. We have to go through a legal process (44 KB PDF) to make the change. This is to let people give us reasons why they agree or disagree.
The species' population has increased from 600 in 1973 to roughly 7100 pairs in 2005. The number of California least tern sites has nearly doubled since the time of listing.
The CA Least Tern has a distinctive black cap. It has black stripes running from the cap across the eyes to the beak. These contrast with a white forehead. Other upper parts are gray. Underparts are white.
CA Least Terns have short, forked tails. Their bills and legs are orange. When a CA Least Tern is flying, you can see a black wedge on the end of its wings.
As its name implies, the least tern is the smallest of North American terns. It is 21-23 cm (around 8¼ to 9 inches) long. Its wingspan is 48-53 cm (around 19 to 21 inches).
Mostly small fishes. Learn more.
CA Least Terns live along the coast. They nest on open beaches kept free of vegetation by the tide. The typical colony size is 25 pair.
Other least terns live inland. The interior least terns (131 KB PDF) are also endangered.
Males perform elaborate aerial displays. After that, they offer fishes to the female. This is called the fish flight display. Nesting starts shortly after it.
Larger birds. Mammals such as raccoons and foxes. Domestic dogs and cats.
The Pacific Coast from San Francisco to Baja California. CA Least Terns winter in Mexico. When feeding, they follow schools of fish and are sometimes seen as far north as southern Oregon.
Dredging, habitat loss, nesting disturbance, pollution, predation by domestic and wild animals.
National Zoo Birds for Kids. Fact sheets and more.
Ornithologists call least terns Sternula antillarum. Scientific names are in Latin or Greek.
The CA Least Tern is a subspecies. So ornithologists add browni. This makes the full name Sternula antillarum browni.
Terns are in the Laridae family.
The colors and patterns of a bird's feathers are called plumage.
The common names of bird species are capitalized. So we write California Least Tern. But if you are writing about terns in general, you should use lower case. Learn more from this Wikipedia article.