Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship weed dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship weed dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance at dawn, Cardiff, UK, March. Highly Commended in the Animal Behaviour Category of the BWPA Competition 2015.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in 'weed dance' courtship display, The Netherlands, March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in courtship display, The Netherlands. March.

Espen Bergersen / Atlantic puffins (Fratercula arctica) group interacting, Hornoya bird cliff, Finnmark, Norway. March.

Marie Read / Royal terns (Sterna maxima) pair crossing bills during courtship behaviour, Fort DeSoto Park, Florida, USA

David Noton / Stars and Milky Way over Durdle Door and the Jurassic Coast, with the lights of Weymouth and Portland beyond, Dorset, England, UK, December 2013.

Staffan Widstrand / Mangrove planting team from CRINEO planting Mangrove trees (Rhizophora) Pulicat Lake, Tamil Nadu, India, February 2013.

Sven Zacek / Sunrise on a wetland forest island in Estonia. August 2011.

Eric Baccega / Chimpanzee (Pan troglodytes) female aged 37 years, portrait with hand on heart. Beauval Zoo Parc, France. Captive.