The battle by Jose Garcia, US. Category: bird behaviour. A great white heron (Ardea herodias occidentalis) fighting a green snake in the Florida Everglades. The fight lasted for nearly 20 minutes with the heron having to release its prey. (Photo by Jose Garcia/2017 Bird Photographer of the Year Awards)

To an outsider, their passion is at times illegal and often on the verge of life and death. But climbing rooftops of high-rise buildings and exploring abandoned facilities is in the blood of these young Muscovites. The small group calls itself “Rudex”, which stands for “roof and decay exploration”, and is akin a Western youth craze known as urbex or “urban exploration” of man-made structures. Here: Urban explorer Vad Him of Rudex team jumps whilst on a rooftop in Moscow, Russia, August 14, 2017. (Photo by Maxim Shemetov/Reuters)

Crowds supporting the Same Sеx Marriage Survey listen to politicians and advocates at Taylor Square in the heart of Sydney's gay precinct on November 15, 2017 in Sydney, Australia. Australians have voted for marriage laws to be changed to allow same-sеx marriage, with the Yes vote claiming 61.6% to to 38.4% for No vote. Despite the Yes victory, the outcome of Australian Marriage Law Postal Survey is not binding, and the process to change current laws will move to the Australian Parliament in Canberra. (Photo by James Alcock/Getty Images)

A tourist train is decorated with Christmas lights in Bogotá, Colombia on December 10, 2017. (Photo by Jaime Saldarriaga/Reuters)

A robot named “Robovie-II”, developed by Japanese robotics research institution ATR, moves around at a grocery store during a shopping assisting experiment by utilizing the robot in an ubiquitous network technology platform in Kyoto, western Japan January 6, 2010. (Photo by Yuriko Nakao/Reuters)

In this Friday, December 5, 2014 photo, Iranian volunteer Asal Moghaddam plays with dogs at the Vafa Animal Shelter in the city of Hashtgerd 43 miles (73 kilometers) west of the capital Tehran, Iran. More than 500 dogs find care and affection at the Vafa Animal Shelter, which was established through an endowment in 2004 and is the country’s only licensed animal refuge. (Photo by Vahid Salemi/AP Photo)

A women attends a class at a driving school in Kabul August 17, 2014. Kabul is one of the world's fastest growing cities and its streets are increasingly blocked by cars and buses. In the city's private driving schools, students pay a $60 fee for a 45-day course, which includes oral and practical driving tests at the country's Traffic Department. Some of the women who have signed up say learning to drive is a way to escape unwanted gazes and physical harassment on the cramped, crowded minibuses that are often the only method of urban public transport. (Photo by Mohammad Ismail/Reuters)

People look through the front windshield of a damaged trolleybus in Donetsk, January 22, 2015. At least seven civilians were killed on Thursday when a shell or a mortar hit a trolleybus stop in the rebel-controlled city of Donetsk in eastern Ukraine, a Reuters witness said. The Reuters cameraman said he saw six bodies on the ground near, and inside, a trolleybus in a southern district of the city. Windows of shops nearby had been blown out by the blast. (Photo by Alexander Ermochenko/Reuters)