Gadwall

Anas strepera

Order: Anseriformes
Family: Anatidae
Presence in the Strait: Presence to be confirmed
IUCN (global): LC · Least concern
In Spanish: Ánade friso

Photograph: Luke, CC BY-SA, vía iNaturalist

Length: 46–56 cm
Wingspan: 84–95 cm
Weight: 760 g

Presence in the Strait

Invernante rara de zonas húmedas (<70). Identificación: Espejuelo y vientre blancos. Macho de aspecto gris con popa negra. Hembra como la del Ánade Azulón pero más pequeña y con bandas laterales naranjas en el pico. Movimientos: Las primeras llegan a finales de agosto y las últimas se van en marzo. Máximos en 1ª q. noviembre y 1ª q. marzo.

Identification

White speculum and belly. Males are grey with a black stern. Females resemble the female Mallard but are smaller with orange edges to mandibles.

Movements

The first arrive at the end of August and the last leave in March. Peaks in the 1st hf. November and 1st hf. March. R: Spain (2), Estonia (1) and United Kingdom (1). Silbón Europeo Ánade Friso Anatidae Tarro Blanco Silbón Europeo Ánade Friso

Ring recoveries

España (2), Estonia (1) y Reino Unido (1) Status: Rare winter visitor to wetlands (<70).

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

14 %

Peak in April. 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: 27 April 1985
Latest record: 27 December 2024

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: LC · Least concern · 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.

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.

Same genus in the Strait

Northern Shoveler49–52 cm · Seasonal · overlapping size
Eurasian Wigeon45–51 cm · Seasonal · overlapping size
Mallard51–62 cm · Resident · overlapping size
Garganey37–41 cm · Migrant
Eurasian Teal34–38 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: Anseriformes
Family: Anatidae
GBIF taxon key: 9362027

Sources

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

Gadwall

Presence in the Strait

Identification

Movements

Ring recoveries

Gallery