Laurent Geslin / Common starling (Sturnus vulgaris) perched on railing, Paris, France

Juergen Freund / Non-diver tourists surrounded by fish, trying out the sea walker from the Sunlover Pontoon, Great Barrier Reef, Queenland, Australia, November 2012

David Tipling / Grey Squirrel (Sciurus carolinensis) climbing on fence, St James Park, London, UK, October

Graham Eaton / A split-level image of a mountain stream, in autumn, with water droplets on lens, Nant Ffrancon Valley, Snowdonia NP, Gwynedd, Wales, UK, October

Pal Hermansen / Wooden walkway through coniferous forest. Near High Coast bridge, High Coast World Heritage Site, Vasternorrland, Sweden. August, 2018.

John Chan / Forster's tern (Sterna forsteri) diving for a fish from a railing, Bolsa Chica Ecological Reserve, California, USA, June.

Franco Banfi / Love locks on a bridge in Irkutsk, Lake Baikal, Siberia, Russia.

Peter Lewis / Stormy South sea in harbour, Hampshire, England, UK. January 2014.

Graham Eaton / Black-headed Gull (Larus ridibundus) on railing. Wirral, England, UK. November.

Andy Rouse / Polar Bear (Ursus maritimus) approaching ship, Svalbard, Norway. Arctic. September.

Brent Stephenson / Immature black-billed gull (Larus bulleri) resting on a wharf railing in evening light. Lake Taupo, Volcanic Plateau, New Zealand, February. Endangered species.

Brent Stephenson / Juvenile Black-billed gulls (Larus bulleri) resting on a wharf railing in evening light. Lake Taupo, Volcanic Plateau, New Zealand, February. Endangered species.