Mahouts return home with their elephants carrying grass to feed them on the eve of the rhino census in Kaziranga National Park in Assam state, India, 24 March 2015. Kaziranga will be closed to visitors for the next two days for a census of the rhinos commencing 25 March, in a previous census in 2013 in the park the population of the Indian rhinos was 2329. (Photo by EPA/Stringer)

A woman whose livelihood depends on selling recyclable wastes collects trash from a dumping site while surrounded by Marabou storks on the outskirts of Uganda's capital Kampala March 31, 2015. (Photo by James Akena/Reuters)

Revelers, covered in coloured powder, celebrate, during a Holi Run Festival in Madrid, Spain, Sunday, April 12, 2015. Thousands of revelers took part in the festival that includes a mini marathon. The festivals are fashioned after the Hindu spring festival Holi, which is mainly celebrated in the north and east of India. (Photo by Andres Kudacki/AP Photo)

Indian Muslim devotees travel in an auto rickshaw during the Urs festival in Ajmer, India, Thursday, April 23, 2015. Thousands of devotees from different parts of India travel to the shrine of Sufi saint Khwaja Moinuddin Chisht for the annual festival marking the saint's death anniversary. (Photo by Deepak Sharma/AP Photo)

Models turned into “humanoid” robots pose on a train at Waterloo Station on October 2, 2016 in London, England for the launch of new Sky Atlantic TV drama Westworld. (Photo by Matt Alexander/PA Wire)

Martin Lacey Jr. with a lion during the premiere of the Circus Krone program “Circus der Preistraeger” at Circus Krone on February 2, 2016 in Munich, Germany. (Photo by Hannes Magerstaedt/Getty Images)

Disguised revellers parade on the occasion of the Cortege during the Carnival in Basel, Switzerland, February 17, 2016. (Photo by Georgios Kefalas/EPA)

A boy sits in a canoe in front of a shed built on a raft in the Makoko fishing community on the Lagos Lagoon, Nigeria February 29, 2016. In Makoko, a sprawling slum of Nigeria's megacity Lagos, a floating school capable of holding up to a hundred pupils has since November brought free education to the waterways known as the Venice of Lagos. It offers the chance of social mobility for youngsters who, like most of the city's 21 million inhabitants, lack a reliable electricity and water supply and whose water-based way of life is threatened by climate change as well as rapid urbanisation. (Photo by Akintunde Akinleye/Reuters)