Family Gulls, Terns, Skimmers (Laridae)

Least Concern

Sandwich Tern (Thalasseus sandvicensis)

figure, drawing, illustration of Sandwich Tern (Thalasseus sandvicensis)

Taxonomy

French: Sterne caugek German: Brandseeschwalbe Spanish: Charrán patinegro
Other common names: Cayenne Tern (“eurygnathus”)
Taxonomy:

Sterna Sandvicensis

Latham

, 1787,

Sandwich, Kent, England

.

Genetic data suggest may be sister to T. elegans#R. Previously also linked with T. bengalensis and T. bernsteini. Recent genetic study#R suggests race acuflavidus may be closer to T. elegans than to nominate sandvicensis; juveniles of the two are highly divergent, birds becoming increasingly alike with age. Form eurygnathus (“Cayenne Tern”; often misspelt eurygnatha#R) previously considered a separate species, but S Caribbean data indicate it is a race or perhaps morph of T. sandvicensis, and that all New World populations (except those of extreme N) have at least small percentage of “Cayenne”-type birds; based on recent genetic study#R, eurygnathus here treated as a synonym of acuflavidus; the two interbreed freely in S Caribbean, and mixed pairs occur in Patagonia and Puerto Rico; in Curaçao typical acuflavidus make up 20% of population, while in French Guiana they comprise less than 1%. Two subspecies recognized.

Subspecies and Distribution
  • T. s. sandvicensis (Latham, 1787) – Sandwich Tern – Europe E to Caspian Sea; winters from Caspian, Black and Mediterranean Seas to coasts of W & S Africa (small but increasing numbers also in NW Europe), and from S Red Sea to NW India and Sri Lanka.
  • T. s. acuflavidus (S. Cabot, 1847) – Cabot's Tern – coast of E North America (Virginia locally to Campeche Bank and Belize), and through Antilles to S Caribbean, wintering from Caribbean S to S Peru and Uruguay; birds formerly assigned to “eurygnathus” breed locally in Caribbean, off Venezuela and French Guiana (Cayenne), and from E Brazil to S Argentina (Buenos Aires, and Patagonia from Chubut to Santa Cruz).
    • What do coloured bullet points mean?

    Descriptive notes

    36–46 cm; 130–311 g (sandvicensis 130–285 g; acuflavidus mostly 175–202 g; “eurygnathus” 170–210 g... read more

    Voice

    Very vocal at breeding colonies and also gives contact calls in flight. The contact call is... read more

    Habitat

    Strictly coastal and mainly a warm-water species. Favoured breeding sites are low-lying, and... read more

    Food and feeding

    Almost entirely fish, mostly 9–15 cm long, particularly menhaden (Brevoortia) and anchovies (Anchoviella) in USA,... read more

    Breeding

    Lays May–Jun in Europe, mid May on Curaçao, Jun in C Brazil, Dec in Argentina. Colonies rarely monospecific; usually nests... read more

    Movements

    Migratory, most populations wintering S of breeding range. Both northbound and southbound post-... read more

    Status and conservation

    Not globally threatened (Least Concern). Global population estimated at 490,000–640,000 individuals including an estimated European population of 79,900–148,... read more

    Recommended citation

    Gochfeld, M., Burger, J. & Garcia, E.F.J. (2019). Sandwich Tern (Thalasseus sandvicensis). 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 https://www.hbw.com/node/54016 on 10 December 2019).