Jack Dykinga / Sandhill cranes (Antigone canadensis) and Snow geese (Chen caerulescens) at sunrise, Bosque del Apache National Wildlife Refuge, New Mexico, USA, November.

Jack Dykinga / Bald eagle (Haliaeetus leucocephalus) perched as Snow geese (Chen caerulescens) fly by, Bosque del Apache National Wildlife Refuge, New Mexico, USA, January.

Jack Dykinga / Snow goose (Chen caerulescens) landing into a tight packed flock on lake, Bosque del Apache National Wildlife Refuge, New Mexico, USA. January.

Jack Dykinga / Snow goose (Chen caerulescens) landing into flock, Bosque del Apache National Wildlife Refuge, New Mexico, USA, January.

Ernie Janes / Brent geese (Branta bernicla) flying with moon, Titchwell, Norfolk, UK, December

John Shaw / Common eider duck (Somateria mollissima) female defending her nest from arctic fox (Vulpes lagopus). Longyearbyen, Spitsbergen. June.

Jack Dykinga / Flocks of Mallard ducks (Anas platyrhynchos) taking off in tree-lined wetlands. Bosque del Apache National Wildlife Refuge, New Mexico, USA.

Terry Whittaker / Mandarin duck (Aix galericulata) male female pair, Reddish Vale Country Park, Greater Manchester, UK. December

Marie Read / Wood Ducks (Aix sponsa), females behave aggressively toward a male (second from right) that is trying to join them on a floating log, autumn, New York, USA, October.

Marie Read / Canada geese (Branta canadensis) two during territorial fight in early spring, Ithaca. New York, USA

David Pattyn / Great crested grebe (Podiceps cristatus) adult with freshly caught fish. Tench (Tinca tinca) to feed to its young chick, Valkenhorst Nature Reserve, Valkenswaard, The Netherlands, June

David Pattyn / Great crested grebe (Podiceps cristatus) adult with young on its back and in the water, Valkenhorst Nature Reserve, Valkenswaard, The Netherlands, June