Gaviotín Elegante/Elegant Tern/Thalasseus elegans

Nombre en español: Gaviotín Elegante

Nombre en inglés: Elegant Tern

Nombre científico: Thalasseus elegans

Familia: Laridae

Canto: Frank Lambert

El charrán elegante (Thalasseus elegans) también denominado gaviotín o pagaza elegante, es una especie de ave charadriiforme de la familia Sternidae.

Descripción

El charrán elegante mide unos 41 cm. Tiene las partes inferiores del cuerpo y la parte inferior de las alas de color blanco con las puntas de color oscuro y la parte superior de color gris pálido. Tiene el pico más largo que la cabeza y con la punta orientada hacia abajo, de color amarillo anaranjado aclarándose hacia la punta. Es de ojos negros y patas negras. Su obispillo es blanco como su cola, que es muy ahorquillada.

En la época de reproducción los adultos presentan un capirote negro crestado hacia atrás que va desde el pico hasta la nuca. En invierno la frente y la parte anterior del píleo se vuelven blancos, quedando de color negro la zona alrededor del ojo y la parte posterior de la cabeza.

Distribución y hábitat

Se reproduce en colonias numerosas en playas arenosas de las costas desde México hasta California para después migrar a las costas de Ecuador, Perú y Chile a pasar el verano, regresando a Norteamérica en marzo. En la isla Rasa, del golfo de California, tiene su principal sitio de anidación. Se alimenta de peces que captura al vuelo en el mar.

Elegant tern

The elegant tern (Thalasseus elegans) is a tern in the family Laridae. It breeds on the Pacific coasts of the southern United States and Mexico and winters south to Peru, Ecuador and Chile.

This species breeds in very dense colonies on coasts and islands, including Isla Rasa and Montague Island (Mexico), and exceptionally inland on suitable large freshwater lakes close to the coast. It nests in a ground scrape and lays one or two eggs. Unlike some of the smaller white terns, it is not very aggressive toward potential predators, relying on the sheer density of the nests (often only 20–30 cm apart) and nesting close to other more aggressive species, such as Heermann’s gulls, to avoid predation.

The elegant tern feeds by plunge-diving for fish, almost invariably from the sea, like most Thalasseus terns. It usually dives directly, and not from the «stepped-hover» favoured by the Arctic tern. The offering of fish by the male to the female is part of the courtship display.

This Pacific species has wandered to western Europe as a rare vagrant on a number of occasions, has nested in Spain and has interbred with the Sandwich tern in France; there is also one record from Cape Town, South Africa, in January 2006, the first record for Africa. An elegant tern was recorded in the British Isles, in Pagham, West Sussex, in June 2017. In May 2021, 1500 sand nests with thousands of eggs were abandoned when a drone crashed land near a nesting site in Bolsa Chica Ecological Reserve, scaring off 2,500 nesting elegant terns and leading to a catastrophic loss.

Etymology

The current genus name is derived from Greek Thalassa, «sea», and elegans is Latin for «elegant, fine». The genus was created when a 2005 study implied that the systematics of the terns needed review.

Identification

This is a medium-large tern, with a long, slender orange bill, pale grey upperparts and white underparts. Its legs are black. In winter, the forehead becomes white. Juvenile elegant terns have a scalier pale grey back. The call is a characteristic loud grating noise like a Sandwich tern.

This bird could be confused with the royal tern or Forster’s tern, but the royal tern is larger and thicker-billed and shows more white on the forehead in winter. Out of range, it can also be easily confused with the lesser crested tern. See also orange-billed tern, and the external link below.

This species is marginally paler above than the lesser crested tern with a white (not grey) rump, with a slightly longer, more slender bill with a different curve. The black of the crest that comes down from the crown extends through the eye, creating a small black «smudge» in front of the eye. On royal terns, the black crest stops at the eye, and lesser crested tern has a less shaggy crest

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