In the spring and summer, the least tern can be identified by its black crown and nape, which contrast with its white forehead.
Least terns weigh approximately one ounce and measure nine inches in length. Females are slightly smaller than males. The least tern's body is slate gray on top and white below, with pointed wings and forked tail. Its bill and feet are yellow. It can be identified in spring and summer by its black crown and nape, which contrast with its white forehead. The black edge of its outer wing is conspicuous in flight.
Least terns inhabit seacoasts, beaches, bays, estuaries, lagoons, lakes and rivers and nest on sandy or gravelly beaches and riverbanks.
The range of the least tern is distributed nearly worldwide. It breeds on the Pacific coast from central California to Peru and on the Atlantic coast from Maine to Argentina, and also breeds along the Colorado, Red, Rio Grande, Missouri and Mississippi river systems and along the Great Lakes. It winters from the Gulf Coast and Central America south to Peru and Brazil.
Least terns feed on small fish, crustaceans and insects. They hover over the water and dive or skim for prey.
Predators include large birds (including American kestrels, great blue herons, crows and owls) and small mammals (including raccoons, skunks, foxes, coyotes, cats and dogs).
The least tern is known for its delicate, graceful and buoyant flight. Its wingbeats are rapid.
These birds breeds in colonies of up to 200 birds. They nest on sandy or gravelly beaches and riverbanks. Nests are scraped in sand and may be lined with shell, gravel or other debris. Both sexes build nests, incubate and care for young. Eggs are laid in clutches of two from late May through June and hatch in 21 days. Chicks leave the nest a few days after hatching , but adults continue to care for them, leading them to shelter in nearby grasses and bringing them food. Chicks fledge in approximately 20 days, but can stay with adults for up to three months. The average lifespan is 15 years, although studies have found individuals up to 21 years old.