The common scoter is a large sea duck, and is a resident and winter visitor to all Irish coasts between October and April. The male is all black with a large bill that has yellow colouration around the nostrils. It forms large flocks on suitable coastal waters and the birds pack tightly together, take off and dive together. They build a nest on the ground close to the sea, near lakes or rivers, in woodland or tundra. Between six and eight eggs are laid at a time.
The common scoter feeds by diving for crustaceans and molluscs. It also eats aquatic insects and small fish.
It is red-listed in Ireland due to declining breeding population.