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)

“In beard and hat”; Udine, Friuli-Venezia Giulia, Italy, 2013. (Photo by Giulio Magnifico)

David Bowie, 1974. David Bowie's quirky character and style was perfectly encapsulated in this shot by Terry O'Neill, which shows the music legend posing next to a barking dog on the artwork for his 1974 album “Diamond Dogs” in London. (Photo by Terry O'Neill)

These beautiful photos capture the tender moments between two young boys who share a unique bond with animals. Elena Shumilova, from Andreapol, Russia, began taking pictures of her sons Yaroslav and Vanya in early 2012 when she received her first professional camera. The pair were immediately accepted by the animals from a young age and their incredible bond continues to strengthen as they get older. Elena, 32, was able to capture images her boys playing with such animals as rabbits, dogs, cats and ducks as they become totally immersed in their communication with their furry friends. (Photo by Elena Shumilova)

Physicist Arie van't Riet uses a series of duel X-ray cameras to capture flowers, plants and small animals in living dioramas. The x-rays are then finished and colorized in Photoshop. Giving way to some breathtaking nature scenes. Photo: “Chameleon and Begonia”. (Photo by Arie van't Riet)

This photo was caught on camera by amateur photographer Kutub Uddin, 27, and was taken in his back garden in Bognor Regis, West Sussex. The red-eyed tree frogs have been Mr Uddin's pets for four months and he often lets them out to roam around his garden. Photo: “Ohh no :( Raining”. (Photo by Kutub Uddin)

A man carries an injured girl after what activists said were five air strikes by forces loyal to Syria's President Bashar al-Assad in Douma, eastern al-Ghouta, near Damascus September 11, 2014. (Photo by Bassam Khabieh/Reuters)