Oscar Dewhurst / Hoatzin (Ophisthocomus hoazin) perched on wooden bar overlooking oxbow lake. Manu National Park, Madre de Dios, Peru. September

Mark Bowler / Aerial view of Yavari-Mirin River and oxbow lake and Amazon Rainforest, Peru, July.

Michel Roggo / Backwaters of the Rio Mamore with meanders and oxbow lake, Beni, Bolivia, January 2001.

Tim Laman / Aerial view of an oxbow lake in the Kinabatangan Wildlife Sanctuary, Sabah, Borneo, Malaysia

Oscar Dewhurst / Social flycatcher (Myiozetetes similis) perched on dead branch overhanging oxbow lake. Manu National Park, Madre de Dios, Peru. September

Oscar Dewhurst / Horned screamers (Anhima cornuta) calling at the edge of oxbow lake. Manu National Park, Madre de Dios, Peru. September. Cropped

Oscar Dewhurst / Social flycatcher (Myiozetetes similis) perched on branch overhanging oxbow lake. Manu National Park, Madre de Dios, Peru. September. Cropped

Oscar Dewhurst / Hoatzin (Ophisthocomus hoazin) perched on wooden bar overlooking oxbow lake. Manu National Park, Madre de Dios, Peru. September

Oscar Dewhurst / Hoatzin (Ophisthocomus hoazin) portrait at Peruvian oxbow lake. Manu National Park, Madre de Dios, Peru. September. Cropped

Sven Zacek / Spring flooding of Mustjogi River and surrounding meadows, aerial view in evening light. Border of Estonia and Latvia. May 2016.

Sven Zacek / Meandering Mustjogi river with frozen lakes, aerial view. Border with Latvia. Valgamaa, Estonia. December 2016.

Konrad Wothe / Rainforest at Sandoval Lake, Tambopata National Reserve, Peru.