The CBRE Urban Photographer of the Year competition – now in its ninth year – encourages professional and amateur photographers to capture cities at work. Here: Dog Walker – 15:00. The competition allows photographers to enter up to 24 images, one representing each hour of the day. (Photo by Johanna Siegmann)

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)

Cosplayers attend Day 3 of WonderCon 2017 at Anaheim Convention Center on April 2, 2017 in Anaheim, California. (Photo by Justin Baker/FilmMagic)

An innovative artist has camouflaged nude bodies by painting them into the worlds most expensive artworks. New York body artist, Trina Merry picked the 20 top dearest paintings, then photographed naked models disguised as part of the piece. Here: Titled 8,100,000 after the price paid for Bal du moulin de la Galette. (Photo by Trina Merry/Caters News)

Workers attempt to bring a tranquillised black rhino to the ground before dehorning in an effort to deter the poaching of one of the world's endangered species, at a farm outside Klerksdorp, in the north west province, South Africa, February 24, 2016. (Photo by Siphiwe Sibeko/Reuters)

A tourist stands at an edge of the singing sand, the 150-metre-high by three-kilometre-long dune that generates a low-pitched, organ-like rumble in dry weather, in Altyn-Emel national park in Almaty region, Kazakhstan, May 12, 2016. (Photo by Shamil Zhumatov/Reuters)

“Rudolf Khametovich Nureyev was a Russian Tatar dancer from the former Soviet Union, primarily known for his work in ballet. Nureyev's artistic skills explored expressive areas of the dance, providing a new role to the male ballet dancer who once served only as support to the women. He defected to the West, despite KGB efforts to stop him. According to KGB archives studied by Peter Watson, Nikita Khrushchev personally signed an order to have Nureyev killed”.

Photo: British ballerina Margot Fonteyn (Margaret Hookham) (1919 – 1991) and her professional partner during his tenure with the Royal Ballet Rudolf Nureyev. (Photo by Potter/Express/Getty Images). 12th December 1965. (Photo by Central Press/Getty Images)

Ke$ha performs live on stage during the second day of the Wireless Festival at Hyde Park on July 2, 2011 in London, England. (Photo by Jim Dyson/Getty Images)