Charlie Summers / Greater Sandhill Cranes (Grus canadensis tabida) flying in dusky light. Bosque del Apache, New Mexico, USA, January.

Charlie Summers / A Pintail Duck (Anas acuta) male on water. Bosque del Apache, New Mexico, USA, January.

Charlie Summers / Greater Sandhill Cranes (Grus canadensis tabida) silhouetted in dusky light, standing in water. Bosque del Apache, New Mexico, USA, January.

Charlie Summers / Greater Sandhill Crane (Grus canadensis tabida) courting the bird on the left. Courtship displays include opening the wings, leaping into the air flapping the wings and picking up something. Bosque de...

Charlie Summers / Great Blue Heron (Ardea herodias) standing in frost and snow at water's edge. Bosque del Apache, New Mexico, USA, New Mexico.

David Tipling / Turkey Vulture (Cathartes aura) carcass strung up in car park at Anhinga Trail in Florida Everglades National Park to discourage Black Vultures from stripping rubber from parked cars, Florida, USA

David Tipling / American Black Vulture (Coragyps atratus) perched on pickup truck in car park at Anhinga Trail, Florida, USA

David Tipling / American Black Vulture (Coragyps atratus) in car park at Anhinga Trail, Florida

Bence Mate / Portrait of Blackbird (Turdus merula) at edge of water, Pusztaszer, Kiskunsagi National Park, Hungary

Bence Mate / Eurasian spoonbill (Platalea leucorodia) in flight, Lake Csaj, Kiskunsagi National Park, Hungary

Bence Mate / Portrait of female Common / Red crossbill (Loxia curvirostra) drinking at pool of water, Pusztaszer, Kiskunsagi National Park, Hungary

Bence Mate / Head portrait of female Common / Red crossbill (Loxia curvirostra) Pusztaszer, Kiskunsagi National Park, Hungary

Bence Mate / Portrait of male Hawfinch (Coccothraustes coccothraustes) perching on branch, Pusztaszer, Kiskunsagi National Park, Hungary

Bence Mate / Portrait of female Brambling (Fringilla montifringilla) Pusztaszer, Kiskunsagi National Park, Hungary

Bence Mate / Portrait of Black-tailed godwit (Limosa limosa) with wings outstretched, Pusztaszer, Kiskunsagi National Park, Hungary

Bence Mate / Juvenile Long-tailed tit (Aegithalos caudatus) calling at waters edge, Pusztaszer, Kiskunsagi National Park, Hungary

Bence Mate / Pair of chaffinches (Fringilla coelebs) at waters edge, Pusztaszer, Kiskunsagi National Park, Hungary