Vultures gather to eat waste in Bica beach, on the banks of the Guanabara Bay, with the Sugar Loaf mountain in background, 500 days ahead the Rio 2016 Olympic Games in Rio de Janeiro March 24, 2015. As part of its Olympic bid, Rio promised to clean up 80 percent of the bay for the games. But local government officials have already admitted that a cleanup by 2016 is not achievable. Despite millions of dollars of investment over the years, the bay still stinks of sewage. Sailors who visited the city for test events complained of a floating sofa and a dead dog in the water. (Photo by Ricardo Moraes/Reuters)

Londoners enjoy a “Silent Night” as Big Ben falls silent, London, UK on August 21, 2017. ose Allerston from Clapham, London said “After a stressful day in the office, I couldn't think of anything better than going home and climbing into bed – but when I saw this bed opposite Big Ben I just couldn't resist getting in for a snuggle”. (Photo by Imagewise Ltd/Rex Features/Shutterstock)

Serbian police officers of the Special Anti-Terrorist Unit pose for a picture in their base outside Belgrade October 8, 2014. When the killing of an unarmed black teenager by a white policeman in Ferguson, Missouri, in August sparked sometimes violent protests, the response of police in camouflage gear and armoured vehicles wielding stun grenades and assault rifles seemed more like a combat operation than a public order measure. Some U.S. police departments have recently acquired U.S. military-surplus hardware from wars abroad, but there are many law enforcers around the world whose rules of engagement also allow the use of lethal force with relatively few restrictions. But for every regulation that gives police wide scope to use firearms, there is another code that sharply limits their use. In Serbia, police may use measures ranging from batons to special vehicles, water cannon and tear gas on groups of people who have gathered illegally and are behaving in a way that is violent or could cause violence, but they may use firearms only when life is endangered. (Photo by Marko Djurica/Reuters)

Darth Mykolaiovych Vader, who is dressed as the “Star Wars” character Darth Vader, poses for a picture as he dries his mask and helmet with a hairdryer in the bathroom of his apartments in Odessa, Ukraine, December 2, 2015. Darth Vader was bent on galactic domination, but his Ukrainian namesake enjoys more mundane pursuits: local politics, walking the family dog and a spot of embroidery. The Ukrainian citizen, who has changed his name to Darth Mykolaiovych Vader, ran for the post of local mayor in October, his political backers dressed as Stormtroopers. In his trademark black outfit, he is a regular sight around Odessa, a major port city on southern Ukraine's Black Sea coast. (Photo by Valentyn Ogirenko/Reuters)

“We take rusty old junk and we put love into it”. The old Motor City has a unique style in bicycles these days: from fat wheels and fake fuel tanks to stretched cycles with powerful sound systems – and even a family-sized BBQ. “Detroit’s custom bike scene developed alongside Slow Roll, a weekly cycle ride started in 2010 by Jason Hall and Mike MacKool. Now upwards of 2,000 people turn up each Monday to cruise a different part of the city. The week I go the crowd seems evenly split between black and white, male and female, city and suburbs. It’s the most inclusive cycle event I’ve ever witnessed”. (Photo by Jason Walker/Slow Roll Monday Nights)

New autopilot features are demonstrated in a Tesla Model S during a Tesla event in Palo Alto, California, 2015. Federal officials say the driver of a Tesla S sports car using the vehicle’s “autopilot” automated driving system has been killed in a collision with a truck, the first U.S. self-driving car fatality. The National Highway Traffic Safety Administration said preliminary reports indicate the crash occurred when a tractor-trailer made a left turn in front of the Tesla at a highway intersection. Joshua D. Brown, of Canton, Ohio, died in the accident May 7 in Williston, Florida, when his car's cameras failed to distinguish the white side of a turning tractor-trailer from a brightly lit sky and didn't automatically activate its brakes, according to government records obtained Thursday. (Photo by Beck Diefenbach/Reuters)

The expertly colourised shots were brought to life by French bank technician, Frédéric Duriez (51). The images were provided by the Valois collection which belongs to the BDIC. “By colourising these photos, I reduce the time that separates us today from this conflict”, said Frédéric. Here: Car cannon sections in firing position, Auxi-le-Château. (Photo by Frédéric Duriez/BDIC/Mediadrumworld.com)

The National Geographic Photo Ark is a travelling exhibition of photographer Joel Sartore’s quest to create a photo archive of biodiversity around the world. So far, Sartore has captured studio portraits of more than 6,000 species – a number that he hopes to double. On 1 July, the ark will open at Melbourne zoo – the first time it has been exhibited in the southern hemisphere. More than 50 portraits will be on display, including many of Australian endangered animals being protected by programs at the zoo itself. These captions have been edited from text supplied by Melbourne zoo. Here: Barking owl. (Photo by Joel Sartore/National Geographic Photo Ark/The Guardian)