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Red-breasted Merganser (Mergus serrator) — photo 1 of 5
© Channel City Camera Club from Santa Barbara, US CC BY 2.0

Ducks, geese, and swans · Waterfowl

Red-breasted Merganser

Mergus serrator

Year-round

Voice

Call

Jochem verweij

0:11

Song

Sonothèque ADVL

0:18

How to recognize it

  • 52–64 cm, large duck

  • Long narrow red bill with serrated edges

  • Male: dark green-sheened head, white neck, rusty breast

  • Female: grey-brown body, rusty head and short crest

About the species

The Red-breasted Merganser stands out by its long, narrow bill, built for catching slippery prey. In breeding plumage, the male is especially striking with a dark green sheen on the head and a strong contrast of white, black, and rusty tones; the female looks much quieter and greyer.

It is a fast flier and spends much of its time hunting. It dives from the surface and chases prey underwater, and during courtship the male gives a rough, crow-like call while the female answers with a harsher note.

It breeds on freshwater lakes and rivers, then moves to coastal waters for winter. Fish make up most of its food, but it also takes crustaceans, aquatic insects, and worms.

Where to find

  • Along harbor basins, estuaries, and tidal river mouths — look for small groups diving almost without a splash and surfacing with a fish in the bill.

  • At canal edges and pond margins with reeds — often on calm water, where a pair stays close together and gives a harsh call.

  • On winter open water near the shoreline — after a short run, it drops under and stays down for several seconds.

  • Near bridges, stone embankments, and rocky seawalls in brackish water — it often feeds right along the edge instead of lingering in one spot.

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