Stanislav Fursov (top) and Ekaterina Simonova from Russia, who are representing the city of Moscow, dance during the Stage style final round at the Tango World Championship in Buenos Aires, Argentina, August 27, 2015. (Photo by Marcos Brindicci/Reuters)

“Eye of a toad”. Animal Portraits, Łukasz Bożycki, Poland. Early spring sees a pond near Łukasz’s home city of Warsaw, Poland, full of mating frogs and a few toads. On this March day, Łukasz shared the pond with them for an evening, sitting in the icy water in his chest-high waders, keeping as still as possible, despite the numbing cold, so that the amphibians could get used to him. “I wanted to find a fresh way of portraying the amphibians”, he says, “at water level”. Using a telephoto lens, he focused on one lone toad and waited for the sun to dip almost below the horizon before pressing the shutter, using flash to bring out the details in the shadow. His prize was “the glorious pool of sunset colour” and fiery glow of the toad’s eye. Nikon D80 + 70-300mm f4.5-5.6 lens + extension tube; 1/125 sec at f9 (-2.3 e/v); ISO 100; built-in flash. (Photo by Łukasz Bożycki)

Valery Bystritskii, 10, gets a fellow student into a lock at Bunny's Gym in July 2015 in Winchester, Tennessee. (Photo by Mike Saliba/Barcroft USA)

A Polisario fighter sits on a rock at a forward base on the outskirts of Tifariti, Western Sahara, September 9, 2016. At a rocky outpost in Western Sahara, a new generation of soldiers who have never known war are mobilising as tensions resurface in one of Africa's oldest disputes after a quarter century of uneasy peace. (Photo by Zohra Bensemra/Reuters)

North Korean leader Kim Jong Un is hugged by children during his visit to Samjiyon County in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang November 28, 2016. (Photo by Reuters/KCNA)

Tyson the Bulldog sits with reindeer antlers on Christmas Day at Central Park in Manhattan, New York City, U.S., December 25, 2016. (Photo by Andrew Kelly/Reuters)

Members of the San Francisco Gay Freedom Day Marching Band and Twirling Corps do their thing down San Francisco's Market Street, June 27, 1982. Police estimate the crowd to be 300,000 for the Lesbian/Gay Freedom Day parade and rally. (Photo by Carl Viti/AP Photo)

Roof-topping enthusiast Daniel Lau takes a selfie with high-rise buildings down below as he stands on the top of a skyscraper in Hong Kong, China on August 15, 2017. A craze that began in Russia has now taken hold in Hong Kong, one of the world's most vertical cities. Mr Lau said he had been inspired by Russian climbers and that he was unafraid of the vertiginous heights he scales. (Photo by ImagineChina/Rex Features/Shutterstock)