Midway Atoll National Wildlife Refuge
Pacific Region
 

Birds of Midway Atoll

Least Tern / Sternula antillarum

Photo of Least Tern

Description

A small tern, 22–24 cm long, with a wingspan of 50 cm, and weighing 39–52 g. The upper parts are a fairly uniform pale gray, and the underparts white. The head is white, with a black cap and line through the eye to the base of the bill, and a small white forehead patch above the bill; in winter, the white forehead is more extensive, with a smaller and less sharply defined black cap. The bill is yellow with a small black tip in summer, all blackish in winter. The legs are yellowish. The wings are mostly pale gray, but with conspicuous black markings on their outermost primaries.

Least Tern
Photo credit: Pete Leary/USFWS

 

Midway Population

Although not common at Midway, a small number have been seen nesting on Sand Island.

Feeding Habits

The least tern hunts primarily in shallow lagoons, where smaller fishes are abundant. It hovers until spotting prey, and then plunges into the water without full submersion to extract dinner. Sometimes the terns feed near shore in the open ocean, especially in proximity to lagoons.

Breeding

Each mating pair produce a single brood. The sexes share nest-building, incubation and care of young. Nests are scraped in sand, shell or gravel, and may be sparingly lined with small shells or other debris. Eggs are commonly laid in clutches of 2 from late May through June, and are incubated by both sexes for 21 days. The young fledge in 19-20 days.
Last updated: February 3, 2011