Mergus merganser
A long, sleek sawbill duck built for chasing fish underwater.
Size: 58-66 cm | Habitat: Pond, Lake & River Birds | Season: All year
Britain's largest sawbill duck, the goosander has a slender, serrated bill perfectly adapted for gripping slippery fish. Males are crisp white with a dark, glossy green head and black back, while females and immatures have a neat chestnut head with a shaggy crest.
Long, low-slung body on water · thin, hooked, orange-red bill (serrated edges) · male: white body, dark green head, no crest · female: grey body, chestnut head with shaggy crest · flies fast and low in a straight line
Goosanders pursue fish underwater in fast rivers and large lakes, sometimes hunting cooperatively in a line to herd shoals into the shallows. They nest in tree holes and, increasingly, purpose-built boxes along wooded riverbanks.
Goosander chicks leave the nest hole within a day or two of hatching, tumbling out and sometimes bouncing unharmed from heights of ten metres or more before following their mother straight to the water.
The Goosander (Mergus merganser) is Britain's largest sawbill duck, its long, thin, serrated bill built for one job: gripping slippery fish underwater. Males in full breeding plumage look almost impossibly crisp and clean, white-bodied with a glossy dark green head, while females and young birds show a neat chestnut head with a shaggy, spiky crest.
Goosanders nest in holes in riverside trees, a habit that leads to one of the more dramatic moments in British bird behaviour: newly hatched chicks leave the nest within a day or two, simply jumping out and tumbling — apparently unharmed — from heights that would seriously injure most other young birds, before swimming off after their mother.
As a fish-eating specialist on rivers and lakes, the goosander sometimes draws criticism from anglers, but its population remains secure, and it's one of the more dramatic diving ducks to watch fishing cooperatively in a line.
🟢 Conservation status: Green (UK Birds of Conservation Concern 5)
Green-listed, with a stable and, in places, expanding breeding population on rivers and lakes across Britain.