A giant river otter, the world's largest otter species, looks out of its enclosure at the newly completed River Safari in Singapore, on March 25, 2013. (Photo by Wong Maye-E/Associated Press)

Artist Princess Tarinan von Anhalt throws paint into the flow of air coming from the engine of Flexjet’s Learjet 40 XR engine to create a painting on a canvas at Signature Flight Support in West Palm Beach, Florida. The artist associated with the Jet Art Group used the help of Flexjet and their plane to spray paint on a canvas to create distinctive paintings to celebrate the 50th anniversary of Learjet. (Photo by Thomas Cordy/The Palm Beach Post)

World War II veterans danced during Victory Day celebrations in Minsk, Belarus, Thursday, May 9, 2013. Belarus and other former Soviet countries celebrated the 1945 victory over Nazi Germany on Thursday. (Photo by Viktor Drachev/AFP Photo)

Gelada baboons (Theropithecus gelada) play in their enclosure at the Zoo in Zurich, Switzerland, Wednesday, May 15, 2013. (Photo by Steffen Schmidt/Keystone/AP Photo)

An undated handout picture released on January 10, 2017 by the Issekinicho publishing house shows an inter- species sexual behaviour between a male Japanese macaque and female sika deer, in Yakushima Scientists revealed on January 10, 2017 the “highly unusual” behaviour of a male monkey filmed trying to have sеx with female deer in Japan – a rare case of inter- species nookie. (Photo by Editions Issekinicho/AFP Photo)

Two friends take a quick selfie during the Grand National Festival at Aintree Racecourse on April 6, 2017 in Liverpool, England. (Photo by WENN)

A guard secures gates of a catfish farm visited by a group of foreign reporters in Pyongyang, North Korea April 17, 2017. (Photo by Damir Sagolj/Reuters)

Wide-angle category winner. Part of the Illusion by Marcus Blatchford (UK). Location: National Dive & Activity Centre, Chepstow, Wales. “This is the deepest inland dive centre in the UK. The dive plan was to explore the deep end, but this time I dived ‘unplugged’ (without my strobes). With the exception of this change to my camera technique, there were no planned shots I wanted to achieve – just a fun dive with ad-hoc photos along the way. Shortly after this photo was captured, in 6C water and two hours of decompression ahead of us, we turned and started the long ascent back to the surface”. (Photo by Marcus Blatchford/Underwater Photographer of the Year 2016)