Black Tern

Chlidonias niger

Order: Charadriiformes
Family: Laridae
Presence in the Strait: Migrant
Abundance: abundant
Protection in Spain: In danger of extinction · Andalusian Catalogue
In Spanish: Fumarel común

Marine taxonomy: validated in WoRMS, AphiaID 137137

Photograph: Ómar Runólfsson, CC BY, vía iNaturalist

Length: 22–24 cm
Wingspan: 63–68 cm
Weight: 75 g

Presence in the Strait

Abundant migrant to coasts. Numbers have fallen over recent years. It also used to breed at La Janda but in smaller numbers than the Whiskered Tern.

Identification

Summer plumage: only member of the group that is black with grey wings. In winter plumage it is similar to a Whiskered Tern but with black ear coverts, crown and nape, dark breast-patch and darker wings in flight. Juveniles are like those of a Whiskered Tern but with darker wings and back, and the leading edge of wings dark grey.

Movements

Peaks in 1st hf. May and 2nd hf. August.

Ring recoveries

Italy (1).

Bioestrecho editorial text. Last revised: 8 September 2026.

Photographs from iNaturalist observations with the licence checked file by file. Those marked “Strait” were taken within the area; place and date are those of each observation.

Calendar in the Strait

29 %

Peak in September. Observations under CC0 or CC BY licences. The distribution also reflects observation effort.

Where it is seen

Open records from the atlas database, in cells of about 3.6 km. Opacity follows the square root of the count, and also reflects where people observe most.

See on the map

First open record: 15 September 1981
Latest record: 13 September 2025

The oldest and the most recent open observation in the extended area. A recent first observation does not mean the species is new: it means nobody had published it openly before.

Conservation

The catalogues, Andalusian and Spanish, are what binds; the Red Book assesses the Spanish population with IUCN criteria, and the global Red List is the context.

LCNTVUENCR

Andalusian Catalogue: In danger of extinction
Spanish Catalogue: In danger of extinction
Red Book of the Birds of Spain 2021: CR · Critically endangered · breeding
Global Red List (IUCN): LC · Least concern

Plan: AVES DE HUMEDALES · Annex I of the Birds Directive

Andalusian Catalogue: Junta de Andalucía, list of 24 April 2025. Spanish Catalogue: MITECO, table of 30 June 2025. Red Book: SEO/BirdLife, 2021 (Annex I). IUCN: via GBIF, 6 September 2026. Red Book and IUCN categories are assessments; catalogue categories are legal obligations.

Phenology compared

Monthly distribution in proportion, by decade. It shows whether the passage is getting earlier or later.

2000–2009

2010–2026

Proportions, not totals: observation effort grew faster than any population.

Where they come from

1 birds ringed in other countries and recovered in the area.

Italy1

See the journey on the map

Same genus in the Strait

Whiskered Tern23–25 cm · Migrant · overlapping size
White-winged Tern21.5–21.5 cm · Vagrant

Species of the same genus that also occur here, ordered by how close they are in size. Being relatives does not mean they are confused in the field, but that is where the doubts start: compare size and season.

Classification

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Charadriiformes
Family: Laridae
GBIF taxon key: 2481119

Sources

Distribution and calendar: Bioestrecho's own database, ingested from GBIF and OBIS
Photograph: Ómar Runólfsson, CC BY, vía iNaturalist
Taxonomy: GBIF backbone, pending WoRMS for marine taxa
Editorial text: written by Bioestrecho
Last revised: 8 September 2026

Black Tern

Presence in the Strait

Identification

Movements

Ring recoveries

Gallery