Little Tern (Sterna antillarum)

Little Tern

[order] Charadriiformes | [family] Sternidae | [latin] Sterna antillarum | [UK] Little Tern | [FR] Petite Sterne | [DE] Amerikanische Zwergseeschwalbe | [ES] Charrancito Americano | [IT] Fraticello americano | [NL] Amerikaanse Dwergstern

Subspecies

Genus Species subspecies Breeding Range Breeding Range 2 Non Breeding Range
Sternula albifrons AF, EU, OR, AU widespread
Sternula albifrons albifrons Europe and n Africa to c Asia, Africa
Sternula albifrons guineae Mauritania to Gabon
Sternula albifrons sinensis India and the Indian Ocean through e and se Asia to Australia

Physical charateristics

The least tern is the smallest North American tern, with a body length of approximately 23 cm and a wingspread of 51 cm. The sexes are similar in appearance. The breeding adult has a black crown and nape, white forehead, black-tipped bill, grey back and dorsal wing surfaces, and snowy white underwing surfaces. In flight, the black wedge on the outer primaries and the
short, deeply forked tail are conspicuous. Immature birds have darker plumage than adults, black eye stripes, white foreheads, and dark bills.
The juvenile is pinkish-buff above with brownish U-shaped markings on the feathers; it has a dusky crown, black eye stripe, and dark shoulder bar on the wings. The first-summer bird is similar to the adult but retains the eye stripe and shoulder bar and has a dark bill and legs and dusky primaries.

Listen to the sound of Little Tern

[audio:http://www.aviflevoland.nl/sounddb/L/Little Tern.mp3]

Copyright remark: Most sounds derived from xeno-canto

wingspan min.: 47 cm wingspan max.: 51 cm
size min.: 21 cm size max.: 25 cm
incubation min.: 18 days incubation max.: 22 days
fledging min.: 19 days fledging max.: 20 days
broods: 1   eggs min.: 1  
      eggs max.: 3  

Range

The eastern least tern (S. a. antillarum) breeds along the eastern coast of the U.S., the Gulf coast, and the Caribbean.

Habitat

Subtropical to temperate regions. Continental populations mainly coastal, but also inland along rivers and on oceanic islands.
Breeds on barren or sparsely vegetated sandy, shell, rocky and coral islands, shingle beaches, spits in estuaries and lakes, salt-marshes and rivers.
Outside breeding season, frequents tidal creeks, coastal lagoons and salt-pans.

Reproduction

Breeds May-June in Europe and India, April in West Africa, in small to medium sized colonies. Forms synchronous subcolonies, usually monospecific. Nest usually bare, but in marshes builds on platorms of shell or vegetation. 2-3 eggs are laid, incubation 21-24 days. Chicks are creamy-grey or white with sparse or dense black spots. First breeding 3 years.

Feeding habits

Least terns (Sterna antillarum) feed almost entirely on small fish that swim near the surface, primarily minnows, throughout their entire life.
Terns, in general, dive into standing or flowing water to secure their prey and have a maximum diving depth of less than 1 meter. Least terns are categorized as surface plungers because they search for prey while flying 5 to 10 m above the water?s surface and plunge into the water to capture detected prey. Least terns catch their prey just below the surface of the water and either eat the fish while flying or carry it to the nest to feed their mate
and chicks. Although fish is the basic dietary item, invertebrates are occasionally consumed by least tern adults and chicks.

Conservation

This species has a large range, with an estimated global extent of occurrence of 470,000 km2. It has a large global population estimated to be 65,000-70,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e., declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern.
Little Tern status Least Concern

Migration

Migratory. West European populations winter in West Africa, probably also South Africa. East European and west FSU populations winter in Red Sea and southern Arabia (and may occur in East Africa). Autumn passage mainly August to early October, most following coasts but some crossing central Europe via river valleys. Spring passage mainly April-May; more rapid and more strictly coastal than in autumn.

Distribution map

Little Tern range map

]]>

Leave a Reply

Your email address will not be published. Required fields are marked *