A brown bear is checked by foreign veterinaries and local staff members at the Four Paws Bear Sanctuary in Pristina, on May 9, 2014. (Photo by Hazir Reka/Reuters)

Kirby Chambliss of the United States flies in formation with Matt Hall of Australia, Yoshihide Muroya of Japan and Nigel Lamb of Britain prior to the third stage of the Red Bull Air Race World Championship in front of the Petronas Towers in Kuala Lumpur, Malaysia, on May 15, 2014. (Photo by Joerg Mitter/Red Bull via Reuters)

A member of the Acorda Capoeira (Awaken Capoeira) group performs on a rooftop in the Rocinha favela in Rio de Janeiro, Brazil, July 24, 2016. In a favela with a history of violence between police and drug gangs, or armed battles between traffickers themselves, capoeira is an outlet that gives kids a sense of community – its practice a collective exercise blending characteristics of drum circles, sparring and tag-team gymnastics. (Photo by Bruno Kelly/Reuters)

Twenty five life-size donkeys have been given pride of place in St Paul's Cathedral as part of an interfaith exhibition. They've been painted by Egyptian and Western artists, to show solidarity for the people of Egypt. Photo: Artist painted donkey statues are displayed in the “Caravan” exhibition on August 30, 2013 in London, England. (Photo by Peter Macdiarmid)

A view of the Hazelwood Power Station across the cooling pondage at sunrise on March 21, 2012 in Melbourne, Australia. The brown coal fueled power station, located in Latrobe Valley is the oldest in Victoria and provides the state nearly 25% of its energy. In 2005 Hazelwood was labeled Australia's least carbon efficient power station by WWF Australia and continues to be a target of issue of environmentalist groups. (Photo by Hamish Blair/Getty Images)

French actress Roxane Mesquida (L) and Josephine De La Baume exchange a kiss on the red carpet prior the screening of “The company you keep” during the 69th Venice Film Festival on September 6, 2012 at Venice Lido. “The company you keep” is presented out of competition. (Photos by Tiziana Fabi/Gabriel Bouys/Christine Pettinger/AFP Photo)

Members of the public admire trees displaying their autumn colours at the Royal Horticultural Society Garden Wisley on October 26, 2011 in Wisley, England. Many deciduous trees have now changed colour as they begin to shed their leaves for Autumn. An extended period of leaf colour change has come about this year due to a warm, dry Spring prompting an early growth spurt and a premature colour change. (Photo by Oli Scarff/Getty Images)

An actor plays an injured passer-by during Exercise Strong Tower, the scene of a mock terror attack at a disused underground station in central London, Britain June 30, 2015. London police held their biggest-ever terrorism drill on Tuesday, pitting the emergency services against a group of marauding attackers, nearly 10 years since four young British Islamists killed 52 people in suicide bombings on London's transport network in July 2005. (Photo by Peter Nicholls/Reuters)