Family Gulls, Terns, Skimmers (Laridae)

Least Concern

Least Tern (Sternula antillarum)


Taxonomy

French: Petite Sterne German: Antillen-Zwergseeschwalbe Spanish: Charrancito americano
Taxonomy:

Sternula antillarum

Lesson

, 1847,

Guadeloupe, Lesser Antilles

.

Closely related to S. albifrons, S. saundersi, S. superciliaris and S. lorata. Long considered a race of S. albifrons, but separated mainly on basis of voice; thus, differs in main call being longer and more disyllabic (3); distinctive low-intensity alarm call “zwreep”, “not at all like that of the Little Tern” (verbalized as “wiik”)#R (2); shorter bill and wing (from published data#R effect size for wing −1.076, score 1); rump and tail greyer (1); moreover, each form possesses a call that the other lacks (unscored). Currently accepted polytypic arrangement disputed by findings of morphometric and biochemical analyses. Form athalassos may be genetically undefinable#R; sometimes included in browni. Proposed forms for birds of Pacific coast of Mexico, mexicana (N & C coast) and staebleri (SW Mexico), supported by some authors#R, but both generally considered inseparable from browni#R#R. Three subspecies recognized.

What do (1) and (2) mean? Learn more about the scoring system.
Subspecies and Distribution
  • S. a. browni (Mearns, 1916) – C California (San Francisco Bay) to Baja California and W & S Mexico; winters mostly along W & S Mexican coast.
  • S. a. athalassos (Burleigh & Lowery, 1942) – inland rivers in C North America, from N Great Plains to Texas and N Louisiana; winters to N Brazil.
  • S. a. antillarum Lesson, 1847 – E USA coast from Maine S to Texas (including lower Rio Grande Valley), and on to Honduras and through Caribbean to N Venezuela; formerly Bermuda. Winters to N Brazil.
  • Recorded as breeding (perhaps nominate subspecies) also on Pacific coast of El Salvador (Bahía de Jiquilisco) and, recently, in Nicaragua (Salinas Grandes)#R and in N Brazil, where a breeding colony (60–70 pairs) was found in 2010 at Curupu Island, off the Amazon coast of Maranhão state#R.

    Descriptive notes

    22–24 cm; 39–52 g (New York 44–52 g, average 47·4 g); wingspan 51 cm. Very similar to S. albifrons, with white forehead, black cap, grey... read more

    Voice

    Distinct from that of the Little Tern S. albifrons (See Taxonomy). A well-known 4-... read more

    Habitat

    Lakes, rivers, estuaries and sandy coastlines. The Californian and E populations are generally... read more

    Food and feeding

    Small fish fry are the most frequent prey when nesting. Principal prey generally is small fish and 50+ species have been identified in its... read more

    Breeding

    The season begins in April in Florida and Texas, May in the West Indies and California, May–June in NE USA, May–July in S... read more

    Movements

    Highly migratory. Pacific breeders arrive late April, and return in August to the coasts of W... read more

    Status and conservation

    Not globally threatened (Least Concern). All races are vulnerable. Due to taxonomic split from S. albifrons, status should be re-examined. The global population of... read more

    Recommended citation

    Gochfeld, M., Burger, J. & Garcia, E.F.J. (2017). Least Tern (Sternula antillarum). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/54033 on 24 May 2017).