Microphones are seen in front of Frida, a female Chihuahua, after the San Francisco Board of Supervisors issued a special commendation naming Frida “Mayor of San Francisco for a Day” in San Francisco, California November 18, 2014. Frida, a previously unknown female Chihuahua, has won her first political office, being named Mayor of San Francisco for the day as part of a campaign to support the city's animal shelter. (Photo by Stephen Lam/Reuters)

A man takes a picture of part of what is set to be the UK's largest street art project on August 19, 2011 in Bristol, England. The See No Evil art project on Nelson Street in Bristol will see several multi story buildings in the street covered with art over the coming days. Organisers hope that the project, which has involved top graffiti artists from all over the world, will become a major tourist attraction for the west country city, often said to the spiritual home of Banksy. (Photo by Matt Cardy/Getty Images)

A feeder trains a Siberian tiger cub at Erdaohe Tiger Park July 2, 2006 in Antu County of Yanbian Chaoxian Autonomous Prefecture, Jilin Province, China. About 15 artificially-fed Siberian tigers from Harbin Siberian Tiger Park are being trained to develop their ability to live in the wild. The wild Siberian tiger is listed as one of the most endangered species in the world, with its existing number estimated at around 400 worldwide, mainly in the northeastern part of China and the Far East of Russia. Reportedly there are more than 1,300 Siberian tigers which have been raised in China. (Photo by China Photos/Getty Images)

CHALLOCK, ENGLAND - MARCH 31: Tony Hall walks with his dog through an installation entitled 'Super Kingdom', which hangs in trees in King's Wood as part of the Stour Valley Arts project on March 31, 2011 in Challock, England. The works by artists Bruce Gilchrist and Jo Joelson of 'London Fieldworks' consist of a series of interesting animal habitats, modelled on the palaces of Stalin, Ceauscescu and Mussolini, and offer nesting sites to many native and migrant species. (Photo by Dan Kitwood/Getty Images)

Tibetan monks create an intricate picture made from coloured sand at St. Mungo Museum of Religious Life and Art on November 23, 2011 in Glasgow, Scotland. The monks, from the Panchen Lama's Monastery, are creating a Sand Mandala as part of a Tantric Buddhist ritual, invoking the presence of the Buddha in a design representing the palace of the deities. (Photo by Jeff J Mitchell/Getty Images)

A veterinarian kisses an 8-month-old cat, wearing a prosthetic two-wheel device, at a veterinary hospital in Chongqing municipality, March 16, 2015. The cat's rear legs lost the abilty to walk after falling from the ninth to fifth floor of a building last November, its since undergone four major surgeries which included removing parts of its organs, local media reported. (Photo by Reuters/China Daily)

In this Thursday, March 19, 2015 photo, workers in outfits made from scrap material parade through a farm on the rooftop of a door manufacturer in Chongqing municipality in southwest China. Employees of the company designed and modeled their garments as part of an environmental sustainability-themed fashion show, which was held by the firm as a morale-booster for employees. (Photo by AP Photo)

An Acehnese female police officer wear a hijab on duty in the street in Banda Aceh, Indonesia, 27 March 2015. Indonesia National Police officially issued a regulation allowing female police officer to wear the Islamic hijab (heads craft) as a part of their uniform. Indonesia is the biggest Muslim population in the world. (Photo by Hotli Simanjuntak/EPA)