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

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

Ole Jorgen Liodden / Hippopotamus (Hippopotamus amphibius) rearing head out of water, creating spray, Lake Naivasha, Kenya.

Kristel Richard / Two wild Przewalski / Takhi Horse (Equus ferus przewalskii) stallions play fighting Hustai National Park, Tuv Province, Mongolia. Endangered species. September.

Ole Jorgen Liodden / Polar bear (Ursus maritimus) pouncing, Svalbard, Norway, July.

Donald M. Jones / Wild Horse (Equus caballus) fighting stallions, Wyoming

Kristel Richard / Two Cambodian Pony stallions play fighting, rearing on back legs, Siem Reap, Cambodia. March 2013

Kristel Richard / An equine trainer, in the traditional white Gujarati clothes, walks a Kathiawari horse mare on her hindlegs without strain, Porbandar, Gujarat, India, December 2012. No release available.

Richard Du Toit / Burchell's Zebra (Equus burchellii) males fighting, Rietvlei Nature Reserve, Gauteng, South Africa

Cheryl-Samantha Owen / Cape Gannet (Morus capensis) juvenile released at sea near Robben Island, Table Bay, after hand rearing and rehabilitation at the Southern African Foundation for the Conservation of Coastal Birds (SAN...

Cheryl-Samantha Owen / Cape Gannet (Morus capensis) released after hand rearing and rehabilitation at the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB) this Cape gannet is released at sea near...

Cheryl-Samantha Owen / Cape Gannet (Morus capensis) juvenile being transported by boat in a cardbord box. To be released after hand rearing and rehabilitation at the Southern African Foundation for the Conservation of Coast...