Diet & feeding
Dives for molluscs such as zebra mussels, insect larvae and some plant material.
Habitat
Lakes, reservoirs, gravel pits and slow rivers; coastal in winter.
Breeding
Nests close to water in dense vegetation, sometimes in old coot nests or tree holes.
Migration
UK breeders are mostly resident; continental birds arrive for the winter.
Vocalisation
Males give a soft whistling display; females a gruff "kurr".