An Indian Runner duck searches for food on a snow-covered meadow in Aitrang, southern Germany, Wednesday. April 19, 2017. (Photo by Karl-Josef Hildenbrand/DPA via AP Photo)

Princess Charlene poses after the arrival of the Riviera Water Bike Challenge in support of the Princess Charlene of Monaco Foundation, in Nice, France, June 4, 2017. (Photo by Eric Gaillard/Reuters)

Public Space series, 2015. This series by Morteza Niknahad and Behnam Zakeri tends toward cinema, taking an almost cartoonish view of modern life in Iran. This work was inspired by the social life of dolphins. (Photo by Morteza Niknahad and Behnam Zakeri/The Guardian)

An eight-year-old St Bernard with the longest canine tongue in the world, measuring 18.58cm (7.31in) in length, as recorded by the Guinness World Records: Amazing Animals, in South Dakota, USA. (Photo by Kevin Scott Ramos/GWR/PA Wire)

A male puma, named Bordo arrives for an examination and tests at a veterinary in Brasilia, Brazil, 31 October 2017 (issued 01 November 2017). Bordo, a young male puma, captured when he was a cub, will become the first animal of his species to be released in a sanctuary in the Brazilian savannah in Goias State close to Brasilia. The sanctuary, a preserve for wild cats, is in the first phase and is located on private lands but state funded. (Photo by Joedson Alves/EPA/EFE)

In a country where some 200 breweries produce well over 1,000 different beers, surely no one is considering brewing their own? Wrong. Here: Arnaud Laloy, member of the Belgian Homebrewers association, adds hop in the brewing process to create his own beer in the garage of his house in Neufchateau, Belgium, August 11, 2016. (Photo by Francois Lenoir/Reuters)

A man carries food supplies on a donkey to Dhalamlam Mountain in the Jafariya district of the western province of Raymah, Yemen June 2, 2016. In villages perched high on a mountain in Western Yemen, residents are a safe distance from a conflict raging throughout most of the country but have had to turn the clock back on their lifestyles by centuries. (Photo by Abduljabbar Zeyad/Reuters)

People in Kathmandu joke that the face mask has now become part of the national dress – an indispensable accessory in an effort to protect themselves from the dust. Nepal has the worst air quality in the world, according to the Environmental Performance Index. (Photo by Pete Pattisson/The Guardian)