An excellent swimmer and diver, it pursues it's fish and
aquatic invertebrate prey underwater. It uses the vegetation
skilfully as a hiding place.
The adult is unmistakable in summer, predominantly dark
above with its rich, rufous colour neck, cheeks and flanks,
and bright yellow gape. The rufous is replaced by a dirty brownish grey in non-breeding and juvenile birds. Juveniles have
a yellow bill with a small black tip, and
black and white
streaks on the cheeks and sides of the neck.
This yellow bill darkens as the juveniles age, eventually
turning black in adulthood.
23 - 29 cms.