Riot police stand guard behind a fire as refinery workers hold a blockade of the oil depot of Douchy-Les-Mines to protest against the government's proposed labour reforms, on May 25, 2016. Refinery workers stepped up strikes that threaten to paralyse France weeks ahead of the Euro 2016 tournament as the government moved to break their blockades, escalating a three-month tug-of-war over labour reforms. (Photo by François L.O./AFP Photo)

Martin Lacey Jr. with a lion during the premiere of the Circus Krone program “Circus der Preistraeger” at Circus Krone on February 2, 2016 in Munich, Germany. (Photo by Hannes Magerstaedt/Getty Images)

A participant of “Bread Procession of the Saint”, takes part in the ceremony in honor of Domingo de La Calzada Saint (1019-1109) who helped poor people and pilgrimage, in Santo Domingo de La Calzada, northern Spain, Wednesday, May 11, 2016. Every year during spring season, “Las Doncellas” (White Virgins), hold on their head a basket cover with white cloth while they walk past along of this old village in honor of the saint. (Photo by Alvaro Barrientos/AP Photo)

A workman smooths out the gravel near the base of British artist Alex Chinneck' latest sculpture “A bullet from a shooting star” on the Greenwich Peninsula in London on September 17, 2015. The 35-metre tall, upside-down electricity pylon overlooks the Canary Wharf financial district. (Photo by Leon Neal/AFP Photo)

Debris fly into the air as foreign fishing boats are blown up by Indonesian Navy off Batam Island, Indonesia, Monday, February 22, 2016. Authorities on Monday sank dozens of fishing boats caught operating illegally in Indonesian waters as part of the country's campaign to battle illegal fishing. (Photo by M. Urip/AP Photo)

A sales woman of a fish shop shows king crabs to a customer and negotiates the price in Noryangjin Fish Market is seen on August 1, 2015 in Seoul, South Korea. Noryangjin Fish Market was established in 1927 as Gyeongseong Susan in Jung-gu near Seoul Station and moved to its current location in 1971. (Photo by Shin Woong-jae/The Washington Post)

A tale of two foxes. Surprising behaviour, witnessed in Wapusk national park, on Hudson Bay, Canada, in early winter. Red foxes don’t actively hunt Arctic foxes, but where the ranges of two predators overlap, there can be conflict. Though the light was poor, the snow-covered tundra provided the backdrop for the moment that the red fox paused with the smaller fox in its mouth in a grim pose. (Photo by Don Gutoski/2015 Wildlife Photographer of the Year)

Pierre Thivillon (R), director of the zoological park of Saint-Martin-La-Plaine and his wife Eliane look at Digit, an 18-year-old female gorilla, on August 19, 2016, in Saint-Martin-La-Plaine between Lyon and Saint-Etienne, southeastern France. The zoological park of Saint-Martin-La-Plaine is a shelter for beasts seized by the justice. (Photo by Philippe Desmazes/AFP Photo)