A man carries his dog as he prays during Vesak Day, an annual celebration of Buddha's birth, enlightenment and death, at Wat Yai Chai Mongkhon temple in Ayutthaya, Thailand, May 10, 2017. (Photo by Athit Perawongmetha/Reuters)

A mural signed by “TV Boy” and depicting Pope Francis and U.S. President Donald Trump kissing, is seen on a wall in downtown Rome, Italy on May 11, 2017. (Photo by Tony Gentile/Reuters)

The National Geographic Photo Ark is a travelling exhibition of photographer Joel Sartore’s quest to create a photo archive of biodiversity around the world. So far, Sartore has captured studio portraits of more than 6,000 species – a number that he hopes to double. On 1 July, the ark will open at Melbourne zoo – the first time it has been exhibited in the southern hemisphere. More than 50 portraits will be on display, including many of Australian endangered animals being protected by programs at the zoo itself. These captions have been edited from text supplied by Melbourne zoo. Here: Barking owl. (Photo by Joel Sartore/National Geographic Photo Ark/The Guardian)

Vehicles are burning as thousands of people take to the streets during the May Day demonstrations on May 1, 2018 in Paris, France. This month celebrates the 50th anniversary of May 68 when France seen millions of students and striking workers, come onto the streets in demonstrations that changed the country. (Photo by Jeff J. Mitchell/Getty Images)

German troops in Stalingrad, USSR. September 10, 1942. (Photo by TASS)

A child looks up to his partner as she stands above the crowd with the support of an elaborate rig of hidden metal rods, during the Bun Festival parade at Cheung Chau island in Hong Kong on May 22, 2018. Thousands of local residents and tourists flocked to an outlying island in Hong Kong to celebrate a local bun festival on Tuesday despite the recording-breaking heat. (Photo by Bobby Yip/Reuters)

New program of Munich's Krone Circus performed by two American artists “The Carmenas” during a press conference in Munich, Germany on January 10, 1962, while sitting in a coffee-house. (Photo by Heinrich Sanden Sr./AP Photo)

Model Bella Hadid walks the runway for the Savage X Fenty Fall/Winter 2018 fashion show during NYFW at the Brooklyn Navy Yard on September 12, 2018 in Brooklyn, NY. (Photo by Kevin Mazur/Getty Images for Savage X Fenty)