Great Crested Grebe

Podiceps cristatus

Appearance:
Medium to large aquatic bird
Largest member of the grebe family
Long neck and head
Long bill 
White face with a black line from the base of the bill to the eye
Red eye
Dark olive-green feet
Breeding plumage:
    Chestnut feathers on side of head
    Black crown and head crest
    Dark brown wings
    White underparts
    White patches on wings
Non-breeding plumage:
    No crest or tippets
    Dark crown bordered by a white face 
    White extends down the foreneck and chest
Juvenile:
     Striped black and white head and neck

I took these photos in September 2014 on one of our visits to London.  I believe they were taken in Regent's Park, as that is my regular stomping ground.  

Learn more about the Great Crest Grebe.