Thomas Thwaites, a 34-year-old researcher from London, has spent the past year creating prosthetics that allow him to roam around on all fours like goat.

The fourth annual BigPicture Natural World Photography Competition aims to celebrate the diversity of life on Earth, and encourages people to protect and conserve it. Here: “The Salmon Catchers”. Terrestrial Wildlife. To capture this view of a mother grizzly bear and her cub, photographer Peter Mather set up a camera trap on a log that he knew the bears tended to traverse while fishing for salmon, in the Yukon River watershed in Canada. (Photo by Peter Mather/BigPicture Natural World Photography Competition 2017)

A man walks past specially designed wash basins in a public toilet at the Foreigners Street on April 26, 2007 in Chongqing Municipality, China. (Photo by China Photos/Getty Images)

A child looks at a polar bear swimming under a water in its enclosure on a hot summer day at Prague Zoo, Czech Republic, July 30, 2015. (Photo by David W. Cerny/Reuters)

A 13-month-old chimp named Fumo carries a “Christmas present” of food treats in wrapping paper under his arm during a Christmas-themed feeding time at Sydney's Taronga Park Zoo, December 9, 2014. Fumo, meaning “chief” or “spear” in Swahili, is one of the latest additions to the zoo's successful primate breeding program. (Photo by Jason Reed/Reuters)

Fareeda, wife of Shameem Ahmad Ganai, who according to Fareeda was arrested during a clampdown a day before the scrapping of the special constitutional status in Kashmir by the government, tends to her husband's sheep in their house, in Pulwama, south of Srinagar, August 13, 2019. (Photo by Danish Siddiqui/Reuters)

An old woman looks from inside a car with bullet holes and shattered windows as she flees fighting in the eastern Ukrainian town of Slaviansk June 9, 2014. REUTERS/Gleb Garanich.

Visitors to West Midlands Safari Park in Bewdley, UK on October 17, 2023 are enjoying the bright October sunshine ahead of the storms to come. A curious giraffe meets eye to eye with a car full of happy visitors while licking the car windscreen with his long tongue. (Photo by Lee Hudson/Alamy Live News)