Riot police hold their weapons during a protest by supporters of Kenyan opposition National Super Alliance (NASA) coalition, along a street in Nairobi, Kenya on October 11, 2017. Opposition leader Raila Odinga, has called for protests this week, reiterated that he would not take part in a re- run of the presidential election on October 26, 2017 if his demands are not met, as Kenya' s Supreme Court last month overturned the August election of President Uhuru Kenyatta citing “irregularities” in the counting of results. (Photo by Thomas Mukoya/Reuters)

Shortlisted: “Two big eyes” by Miao Yong (Zejiang province, China). Damselflies look over the leaves. “I was photographing insects in a park near my home when suddenly I found two damselflies in the grass. They kept flying and it was very difficult to focus until suddenly they parked behind a leaf”. (Photo by Miao Yong/2017 Royal Society of Biology Photographer of the Year)

A dead whale is seen on the shore of the Ipanema beach in Rio de Janeiro, Brazil November 15, 2017. A biologist, Rafael Carvalho, said on Wednesday the whale appeared to have been dead for a few days. Authorities were urging beachgoers who had flocked to Ipanema on a national holiday to stay away from the animal. However, many were spotted near the carcass with some people playing in the water nearby. The whale is approximately 39 feet (12 metres) long and weighs about 25 tonnes. (Photo by Pilar Olivares/Reuters)

A policeman stands next to supporters of Kenyan President Uhuru Kenyatta lying unconscious after being beaten by police when they tried to storm through gates to get in during Kenyatta's inauguration ceremony at Kasarani stadium in Nairobi, Kenya Tuesday, November 28, 2017. Kenyatta is being sworn in on Tuesday, ending a months-long election drama that saw the first vote nullified by the country's top court and the second boycotted by the opposition. (Photo by Ben Curtis/AP Photo)

In this November 11, 2017 photo, children dressed in traditional outfits play during the Azorean Culture Festival which celebrates the culture of the Azores, the Portuguese island chain in the mid-Atlantic, in Enseada de Brito, in Brazil's Santa Catarina southern state. “We have to make sure that our culture always stays alive, not let it die”, said Andre Cordeiro, who leads one of the singing and dancing groups that performed this year. “We are able to pass it on from generation to generation”. (Photo by Eraldo Peres/AP Photo)

Homeless man Alonzo Harrison, 47, takes a nap on a bench at Pershing Square decorated with Christmas lights in the background on Monday, December 4, 2017, in Los Angeles. A homeless crisis of unprecedented proportions is rocking the West Coast, and its victims are being left behind by the very things that mark the region's success: soaring housing costs, rock-bottom vacancy rates and a roaring economy that waits for no one. (Photo by Jae C. Hong/AP Photo)

People stand near beached sperm whales on January 13, 2016, after they became stranded on the Dutch island of Texel the day before. Five sperm whales which became stranded on Texel have died, officials said January 13. Experts said the beached whales had already been badly injured and their chances of survival were poor. Volunteers tried to save them but called off their efforts late in the night because of bad weather and darkness, ANP news agency said. (Photo by Remko de Waal/AFP Photo/ANP)

Arabian Saluki dogs chase a lure during a race at the Mazayin Dhafra Camel Festival in the desert near the city of Madinat Zayed, 150 kms west of Abu Dhabi, on December 26, 2017. The festival, which attracts participants from around the Gulf region, includes a camel beauty contest, a display of UAE handcrafts and other activities aimed at promoting the country's folklore. (Photo by Karim Sahib/AFP Photo)