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)

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)

Space shuttle Atlantis (R) remains docked to the International Space Station photographed by NASA astronaut Ronald Garan during a planned six-and-a-half-hour spacewalk July 12, 2011 in space. Space shuttle Atlantis has embarked on a 12-day mission to the International Space Station where it will deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts. This was the final mission of the space shuttle program, which began on April 12, 1981 with the launch of Colombia. (Photo by NASA via Getty Images)

A Ugandan soldier, part of the 9,000-strong African Union Mission in Somalia, (AMISOM) walks through the Banadir soccer stadium on August 15, 2011 in Mogadishu, Somalia. The stadium, Somalia's largest soccer facility, had been under control by Islamic extremist Shabab militants for the past two years until they withdrew from the capital more than a week ago. (Photo by John Moore/Getty Images)

Geof Kern is an internationally renown photographer based in Dallas. He stands among the most awarded American photographers.