Ferruginous Duck

Aythya nyroca

Order: Anseriformes
Family: Anatidae
Presence in the Strait: Occasional
Protection in Spain: In danger of extinction · Andalusian Catalogue
In Spanish: Porrón pardo

Photograph: Martin Mecnarowski, CC BY-SA, vía iNaturalist

Length: 38–42 cm
Wingspan: 63–67 cm
Weight: 525–600 g

Presence in the Strait

Occasional. It bred at Soto del Torero (Vejer de la Frontera) in 1935. Eleven recent records (64 birds) throughout October and March, with peaks in November (15) and January (36).

Identification

Smaller than the Pochard, appearing very dark with white stern. In flight, white belly and wing-bars. Male has white iris, which is brown in the female.

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

28 %

Peak in October. 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: 23 October 1997
Latest record: 31 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: 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): NT · Near threatened

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.

Same genus in the Strait

Tufted Duck40–47 cm · Seasonal · overlapping size
Common Pochard42–49 cm · Seasonal · overlapping size

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: 2498259

Sources

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

Ferruginous Duck

Presence in the Strait

Identification

Gallery