Walkers cross the river Waalbrug during the first day of the 98th annual four-days walking event, the “Vierdaagse” in Nijmegen, Netherlands, July 15, 2014. The “Nijmeegse Vierdaagse” is an annual public four-day field march which is held since 1909 in the third week of July. (Photo by Erik van 't Wout/EPA)

Arctic wolves in their new enclosure in the wildlife park in Hanau, Germany, 10 February 2015. The pack is one of the park's main attractions, which specializes in local and European breeds. (Photo by Boris Roessler/EPA)

A hot air balloon floats past an almost full rising moon on a warm fall evening near Encinitas, California October 5, 2014. (Photo by Mike Blake/Reuters)

A large bull walrus returns to the shores of Prins Karl Forland after diving and feeding on clams. (Photo by Paul Nicklen/National Geographic). Svalbard, Norway, 2011

Photographer John Maher, once the drummer with punk bank Buzzcocks, travelled to the Outer Hebrides to photograph abandoned crofters’ cottages – many of which, like this one, have seemingly been untouched since. Here: “Peat Fire”. Taken in March 2013 on the east coast of Harris. The fire is from muir-burning, when farmers burn off grasses and heather to improve grazing for their sheep. (Photo by John Maher/The Guardian)

Dogs of a visitor pass by the grave of Marquise and Tony, the two small dogs of the Princess Lobanoff de Rostoff at the cimetiere des chiens (Cemetery of dogs) ahead of the commemoration of All Saints Day at the Montmartre cemetery in Asnieres, northern Paris, France, October 30, 2016. (Photo by Charles Platiau/Reuters)

A White Crested Poland is seen at the National Poultry Show on November 20, 2016 in Telford, England. The annual event continues to grow with around 7000 entries this year from all around the world. (Photo by Leon Neal/Getty Images)