Shepherds lead their sheep through the centre of Madrid, Spain, Sunday, October 25, 2015. Shepherds have guided a flock of 2,000 sheep through Madrid streets in defense of ancient grazing, droving and migration rights increasingly threatened by urban sprawl and modern agricultural practices. Tourists and city-dwellers were surprised to see the capital's traffic cut to permit the ovine parade to bleat bells clanking its way past the city's most emblematic locations. (Photo by Daniel Ochoa de Olza/AP Photo)

Masks that come with T'antawawas bread are displayed in a popular market of La Paz, October 27, 2015. Residents of La Paz city have started to prepare offerings for their dead relatives next Sunday as part of the All Saints' Day celebrations. The offerings include things the deceased liked during their life, such as fruits, food, breads and drinks, according to local media. (Photo by David Mercado/Reuters)

A monkey catches knives as it balances on a board during a daily training session at a monkey farm in Baowan village, Xinye county of China's central Henan province, February 2, 2016. Baowan village of China's central Henan province appears to be your average farming community from the surface, but at a closer look, one can hear monkey hoots from every direction. Although no official number exists, villagers say that they have been a breeding ground for both monkeys and monkey trainers for centuries. (Photo by Jason Lee/Reuters)

Indonesian mahouts (elephant masters) bathe elephants prior to a daily patrol at a Conservation Respons Unite (CRU) to control elephant-human conflicts in Serbajadi, East Aceh on April 7, 2016. Elephants have joined the front line in the fight against poaching and illegal logging in the dense jungles of Sumatra. Guided by their Indonesian mahouts, they trek alongside rivers, over rough terrain and deep into the rainforest in an area that is home to numerous endangered species, from orangutans to tigers, but which has suffered devastating deforestation in recent years. (Photo by AFP Photo/Januar)

Schoolchildren play music to entertain and inspire people on their way home from work Tuesday, March 29, 2016 in Pyongyang, North Korea. North Korea has called a 70-day loyalty drive areas of a major congress of the ruling party scheduled for early May and everyone from students to coal miners have been mobilized nationwide to demonstrate their devotion to the leadership. (Photo by Eric Talmadge/AP Photo)

A Syrian boy is comforted as he cries next to the body of a relative who died in a reported airstrike on April 27, 2016 in the rebel-held neighbourhood of al-Soukour in the northern city of Aleppo. The Syrian army was preparing an offensive to retake the whole of Aleppo, as fighting in the divided second city killed 38 civilians in a new blow for a tattered truce. Nearly 200 people have been killed in Aleppo in the past week as rebels have pounded government-held neighbourhoods with rocket and artillery fire and the regime has hit rebel areas with air raids. (Photo by Karam Al-Masri/AFP Photo)

Residents carry a slaughtered pig with a bamboo pole as they walk home on a street, which was shut to traffic due to ice, in Leishan county, Guizhou province January 31, 2015. Blizzards and icy rain that lasted for several days at the end of January have disrupted traffic, collapsed houses and decimated crops in central Chinese provinces, Xinhua News Agency reported. (Photo by Reuters/Stringer)

In this Friday, February 6, 2015 photo, sandhill cranes begin to stir after resting for the night at a roosting location along their winter migration route in Cecilia, Ky. According to counts made by biologists with the Kentucky Fish and Wildlife Resources, about 12,000 of the birds have stopped in Cecilia this week during their winter northward migration on their way to their nesting grounds in the Great Lakes region. (Photo by David Stephenson/AP Photo)