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)

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.

The males, of the Oriental Garden species, are battling over territory in Solapur in the Maharashtra state, India on May 20, 2022. Occasionally, the tussle can be brutal, ending in a fatality with one lizard biting another to encourage them to retreat. (Photo by Ratnakar Hiremath/Solent News)

Khansa, an eight month old critically endangered Bornean orangutan shows off it's two front-teeth, at the Singapore Zoo on Thursday, January 11, 2018 in Singapore. The Singapore Zoo is active with its breeding programs as part of its wildlife preservation efforts. This is the Zoo's 46th successful orangutan birth. (Photo by Wong Maye-E/AP Photo)

A baby orangutan called Barney shows off his dancing at Ragunan Zoo in Jakarta, Indonesia in the first decade of November 2023. (Photo by Syahrul Ramadan/Media Drum Images)

Vendors selling bread wait for customers at a roadside hotel in Quetta on March 25, 2024. (Photo by Banaras Khan/AFP Photo)

A monkey jumps from a branch at Yangon Zoological Gardens in Yangon, Myanmar, 06 April 2016. Yangon Zoological Gardens (Yangon Zoo) is the oldest and second largest zoo in Myanmar. (Photo by Lynn Bo Bo/EPA)