Markus Varesvuo / Two Slavonian / Horned grebes (Podiceps auritius) on water, Uto, Finland, May

Markus Varesvuo / Horned / Slavonian grebe (Podiceps auritus) two individuals fighting in water, Finland May

Sven Zacek / Horned grebe (Podiceps auritus) with fish in beak. Harjumaa, Northern Estonia. July.

Sven Zacek / Horned grebe (Podiceps auritus) shaking itself dry after diving. Harjumaa, Northern Estonia. July.

Paul Hobson / Slavonian grebe (Podiceps auritus) on water in breeding plumage, Iceland. June

Paul Hobson / Slavonian grebe (Podiceps auritus) on water in breeding plumage, Iceland. June

Paul Hobson / Slavonian grebe, Podiceps auritus, breeding plumage, Iceland

Alan Murphy/ BIA / Horned Grebe (Podiceps auritus) on floating nest, Iceland

Roger Powell / Slavonian / Horned grebe (Podiceps auritus) adopting threatening pose to ward off an intruder into his breeding territory. Kolvik, Porsanger, Finmark, Norway

Roger Powell / Slavonian / Horned Grebe (Podiceps auritus) male escaping by walking across the iced surface of the lake after being driven off by the dominant male holding territory. It is extremely rare for grebes...

Roger Powell / Slavonian / Horned Grebe (Podiceps auritus) male escaping by walking across the iced surface of the lake after being driven off by the dominant male holding territory. It is extremely rare for grebes...

Roger Powell / Slavonian / Horned Grebe (Podiceps auritus) male escaping by walking across the iced surface of the lake after being driven off by the dominant male holding territory. It is extremely rare for grebes...