Charrán hollín

Bird Profile: Sooty Tern

1. Nombre del ave

English Name: Sooty Tern

Scientific Name: Onychoprion fuscatus

2. Aspecto

The Sooty Tern (Onychoprion fuscatus) is an intricately patterned bird. With unique colouration of black and white, it is easily noticeable. The upper parts of the bird are a lustrous black, while its underparts are predominantly white. The bird possesses a distinctive black triangle around its eyes that extends to its beak, which is thin and sharp and a contrasting bright yellow.

The bird tends to have a uniform look with only slight changes during the breeding season. Juvenile Sooty Terns have a scalloped appearance with a greyish bar on their upperwing coverts. There is little visible sexual dimorphism between males and females, with both sexes maintaining similar appearances.

3. Tamaño

Sooty Terns are medium-sized birds with a length averaging between 33-36 cm (13-14 inches), and an impressive wingspan reaching up to 82-94 cm (32-37 inches). The bird’s weight ranges between 150-250 grams.

4. Hábitat y distribución

The Sooty Tern is a pelagic seabird, often located in warmer oceans. They range from the subtropics into the tropics and can be found in continents like Asia, Africa, North, and South America, with the densest populations in the Indian Ocean and the Caribbean Sea. The Sooty Tern favours coastal, marine, and island habitats, far from the mainland.

5. Datos de interés

The Sooty Terns are known for their long, uninterrupted flights. They may spend several years at sea before making landfall. These birds are also renowned for their ‘wideawake’ or ‘wideawakes’ calls due to their loud, distinctive cries. Their cultural significance extends to the Bahamas, where they are deemed ‘good luck’ if they fly over a couple’s wedding.

6. Dieta

The Sooty Tern’s diet is fundamentally piscivorous, feeding principally on small fish and squid. They plunge into the water in a striking display and come out with a morsel. They can also feed on crustaceans and other small sea creatures when the opportunity arises.

7. Behaviour & Sounds

The Sooty Terns are social birds, often seen in large colonies during breeding seasons. Their communal nesting style involves laying eggs on bare ground or shallow scrapes. When it comes to their sounds, they’re known for a cacophonous, collective ‘wideawake’ call, particularly in their breeding colonies.

8. Estado de conservación

Sooty Terns are listed as ‘Least Concern’ according to the IUCN Red List, due to their large, widespread population. Nevertheless, the bird faces threats from climate change and habitat modification.

9. Vida útil

The average lifespan of a Sooty Tern in the wild is around 32 years, while in captivity, it can live up to 35 years, proving their resilience.

10. Notas adicionales

In other languages, the Sooty Tern is known as “Gaviotin negro” in Spanish and “Sterne fuligineuse” in French. Sooty Terns, due to their diet, play an important role in marine ecosystems by controlling the population of small fish and squid. Humans influences come from egg harvesting in some places and habitat changes due to tourism. Despite these challenges, the Sooty Tern continues to thrive, keeping the oceans lively with their loud, uplifting calls.