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Bioestrecho

SpeciesBirds

Red-breasted Merganser

Mergus serrator

Order
Anseriformes
Family
Anatidae
Presence in the Strait
Occasional
IUCN (global)
LC · Least concern
In Spanish
Serreta mediana

37% of its open observations in the area are from January.

Photograph: Thomas Galewski, CC BY, vía iNaturalist

Length
51–62 cm
Wingspan
70–86 cm
Weight
1,300–1,700 g
020406080100LENGTH51–62 cmWINGSPAN70–86 cmcentimetres

Presence in the Strait

Occasional. Nine records (13 birds): on 19.03.82 and 18.03.89 at Ceuta, three birds on 12.03.83 at the River Guadiaro estuary, on 17.12.88 at Gibraltar, on 25.12.95 at Punta Carnero (Algeciras), on 10.01.84 at Poniente Beach in La Línea, in January ‘96 at Rinconcillo Beach (Algeciras), two birds in the marshes of Barbate 15.12.05 and two birds in Algeciras Bay 22.12.10. Towards the end of the 19th Century it was more common and groups of over 30 birds could be seen in the Bay of Algeciras. Identifications: Slender, with a crest, narrow red bill and fast wing-beats in flight. In eclipse, the male is similar to the female but maintains wing pattern. Juveniles are similar to females but with a duller red bill. They breed the N of Europe and Iceland. Anatidae Negrón Común Negrón Especulado Porrón Osculado Serreta Mediana

Bioestrecho editorial text. Last revised: 8 September 2026.

Gallery

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.