Morley Read / Aerial shot of a group of wild ponies (Equus caballus) in paramo landscape at the base of Cotopaxi Volcano, Ecuadorian Andes, 2018.

Alex Mustard / Two female Common seahorses (Hippocampus kuda) fighting over territory on the seabed. The brief fight was preceeded by a ritualised, synchronised parade. Bitung, North Sulawesi, Indonesia. Lembeh Stra...

Alex Mustard / Common seahorse (Hippocampus kuda) female wrapping her prehensile tail around piece of wood on the seabed. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Ben Gillett / Slow motion clip of a female Appaloosa horse grooming a male, Bristol, England, UK, May.

Nick Hawkins / Atlantic bluefin tuna (Thunnus thynnus) off Antigonish, Nova Scotia, Canada. October .

SCOTLAND: The Big Picture / Curled octopus (Eledone cirrhosa) amongst a horse mussel bed (Modiolus modiolus) Shetland, Scotland, UK, August.

Klein & Hubert / Mustang stallion kicking out after winning fight. Rocky Mountains, USA, June.

Klein & Hubert / Mustang horses, chestnut painted overo mare and her buckskin daughter, age two years, Nevada, USA.

Klein & Hubert / Dun foal jumping over a palomino yearling while playing. Nevada, USA.

Nick Upton / Feral horse (Equus caballus) walking on a remote sandy beach, near Arta, Mallorca, Spain, August.

Jack Dykinga / Gaucho herding horses on the shoreline of Lago Almarga in the morning light, with Torres del Paine mountains in background under stormy skies. Patagonia, Chile.

Francisco Marquez / Round up of wild mares and foals from marshland to the corrals of the town. Donana National Park, Spain. September 2014.

Klein & Hubert / Fjord or Norwegian fjord horses trotting in grass meadow in fall, France

Klein & Hubert / Fjord or Norwegian fjord horse galloping in grass meadow in fall, France

Phil Savoie / Point-to-Point horse racing, low angle view of racehorses jumping fence, Monmouthshire, Wales, UK. March 2014.

Phil Savoie / Point-to-Point horse racing, low angle view of racehorses jumping fence, Monmouthshire, Wales, UK. March 2014.

Phil Savoie / Point-to-Point horse racing, low angle view of racehorse jumping fence, Monmouthshire, Wales, UK. March 2014.

Cyril Ruoso / Feral Horses (Equus caballus) gathering around waterhole, Namib-Naukluft National Park, Namibia.

Jordi Chias / European barracuda (Sphyraena sphyraena) and Bluefish (Pomatomus saltatrix) circling baitball of Atlantic horse mackerel (Trachurus trachurus) Formigas Islets, Azores. Finalist in the Underwater Categ...

Dave Bevan / Close-up of a group of Wood ants (Formica rufa) carrying a dead insect back to their nest, Bedfordshire, England, UK, August.

Dave Bevan / Close-up of a group of Wood ants (Formica rufa) carrying a dead Common wasp (Vespula vulgaris) back to their nest, Bedfordshire, England, UK, August.

Carol Walker / Two wild pinto Mustang stallions battle for dominance in Sand Wash Basin, Colorado, USA.

Carol Walker / Wild pinto Mustang mare and foal running in Sand Wash Basin, Colorado, USA.

Carol Walker / Head portrait of grey Arabian stallion running in desert dunes near Dubai, United Arab Emirates.

Carol Walker / Two wild Mustang stallions fighting in the White Mountain Herd Area, Wyoming, USA. August.

Carol Walker / Two white Camargue horses in ocean of Camargue, France, Europe. May.

Carol Walker / Wild Mustang horse rearing, Pryor mountains, Montana, USA. June.

Klein & Hubert / Friesian horse (Equus caballus), mare standing in snow, France.

Stephen Dalton / Horse fly (Tabanus sp) male taking off from poppy seed-head (Papaver rhoeas) Sussex, UK

Floris van Breugel / Wild horse / mustang in open landscape, White Mountains, California, USA, July

Niall Benvie / Icelandic horse foal near Stokkness, Iceland, September.

Niall Benvie / Young Icelandic horse near Stokkness, Iceland, March.

Kristel Richard / Two cowboys mounted on a Pantaneiro stallion, round up a band of wild Pantaneiro horses, Pantanal, Mato Grosso do Sul, Brazil. August 2015.

Juan Carlos Munoz / Close up of horse wearing bridle, Sierra de Gredos, Avila, Castile and Leon, Spain.

Juan Carlos Munoz / Close up of horse wearing bridle, Sierra de Gredos, Avila, Castile and Leon, Spain.

Jeff Vanuga / White horses of the Camargue galloping through marshes in the Camargue, France. April.

Jeff Vanuga / White horse of the Camargue galloping through marshes in the Camargue, France. April.

Jeff Vanuga / White horses of the Camargue galloping through marshes in the Camargue, France. April.

Aflo / Horse walking through heavy snowfall, Shimokita Peninsula, Hokkaido, Japan.

Klein & Hubert / Two semi-wild Criollo foals, a gray sabino colt and a sorrel / chestnut filly, Tierra del Fuego.

Kristel Richard / Headshot of two rare black Kladruber stallions, harnessed for driving, at the Great Riding festival, in Slatinany national stud, Pardubice Region, Czech Republic. June 2015.

Pascal Pittorino / Przewalski's horse (Equus ferus przewalski) head portrait, captive, Lozere, France, December.

Cheryl-Samantha Owen / Aaron Price riding his horse 'Beau' over his Ranch, Gracie Creek, Sandhills, Nebraska. Garfield County, Nebraska, USA. October 2014.

Cyril Ruoso / Icelandic horses, group of three interacting, Iceland, August. Non-ex

Roland Seitre / Przewalski horses (Equus ferus przewalskii) mother and foal, reintroduced in Takhin Tal by the International Takhi Group, Gobi Desert, Mongolia.

Roland Seitre / Przewalski's horse (Equus ferus przewalskii) grazing in buttercups, Parc de la Haute Touche, Obterre, France. May. Captive, occurs in Central Asia.

Klein & Hubert / Young Haflinger stallion in alpine meadow, Austria.

Klein & Hubert / Purebred Arabian horse, grey mare and her 3-weeks bay foal cantering through field, France.