Ring-billed Gull

Larus delawarensis

Order: Charadriiformes
Family: Laridae
Presence in the Strait: Vagrant
IUCN (global): LC · Least concern
In Spanish: Gaviota de Delaware

Photograph: Judy Gallagher, CC BY-SA, vía iNaturalist

Length: 41–49 cm
Wingspan: 112–124 cm
Weight: 500 g

Presence in the Strait

Accidental. A second-year bird on 11.08.84 at the River Guadiaro estuary, one winter visitor 84/85 at Gibraltar, and one more on 20.01.65 at Barbate that had been ringed on 27.06.64 in Ontario (Canada), 5,917 Km. away.

Identification

The size of a Common Gull with pale-grey upperparts. Adults have yellow iris and a broad black bill-band. Second-winter birds have white tails with partial black band. They breed in North America.

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

43 %

Peak in January. 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: 26 January 2009
Latest record: 10 April 2021

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: Not included
Spanish Catalogue: Not included
Red Book of the Birds of Spain 2021: NE · Not evaluated · wintering or migrating
Global Red List (IUCN): LC · Least concern

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.

Same genus in the Strait

Audouin´s Gull48–52 cm · Seasonal · overlapping size
Mew Gull38–44 cm · Occasional · overlapping size
Laughing Gull39–46 cm · Vagrant · overlapping size
Mediterranean Gull36–38 cm · Seasonal
Lesser Black-backed Gull52–67 cm · Seasonal

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: 2481134

Sources

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

Ring-billed Gull

Presence in the Strait

Identification

Gallery