Carol Walker / A wild black curly stallion bowing his head, posturing at another stallion, Salt Wells Creek, Wyoming, USA. May.

Carol Walker / Two wild stallions fighting, a bay roan and a black stallion, Salt Wells Creek, Wyoming, USA. June.

Carol Walker / A wild red roan stallion rearing up as another stallion approaches, Salt Wells Creek, Wyoming, USA. May.

Carol Walker / Three wild stallions, two greys and a sorrel, standing in a group, Lost Creek, Wyoming, USA. July.

Carol Walker / Wild curly stallion posturing, portrait, Salt Wells Creek, Wyoming, USA. June.

Carol Walker / Wild Bay stallion leading his grey mare across grassland, Lost Creek, Wyoming, USA. July.

Andy Sands / Slime mould (Stemonitis sp.) newly emerged bright yellow sporangia on rotting log, Buckinghamshire, England, UK. September. Focus stacked.

Andy Sands / Wrinkled peach fungus (Rhodotus palmatus), young fungus growing from Elm log showing characteristic guttation, Hertfordshire, England, UK. November. Focus stacked.

Andy Sands / Holly parachute fungus (Marasmius hudsonii) young 2mm tall fungus after rain, with water droplets caught among hairs, Buckinghamshire, England, UK. November. Focus stacked.

Bernard Castelein / Robin (Erithacus rubecula) juvenile, standing in shallow water, Brasschaat, Belgium. July.

Bernard Castelein / Four Sanderlings (Calidris alba) foraging at low tide, Zeeland, The Netherlands. February.

Bernard Castelein / Purple sandpiper (Calidris maritima) portrait, Zeeland, The Netherlands. February.