A gibbon drinks from a soft drink bottle, given by a tourist, at a zoo in Kunming, Yunnan province, June 18, 2015. (Photo by Wong Campion/Reuters)

Fireworks explode above Singapore's financial skyline at dusk as part of celebrations for the nation's 50th year of independence, Sunday, August 9, 2015, in Singapore. Singapore declared independence on August 9, 1965. (Photo by Wong Maye-E/AP Photo)

Mongolian President Tsakhiagiin Elbegdorj (C) walks towards the media after casting his vote for the parliamentary elections at a polling station in Ulaanbaatar, Mongolia, June 29, 2016. (Photo by Jason Lee/Reuters)

Indian mourners perform a cremation on the roof of a building overlooking The Manikarnika Ghat in Varanasi on August 23, 2016. India's holy city of Varanasi has been forced to halt cremations along the banks of the sacred river Ganges as deadly floods from monsoon rains hit parts of the country, an official said. More than 100,000 people have been forced from their homes in recent days in northern Uttar Pradesh and neighbouring Bihar states as rain-swollen rivers burst their banks. (Photo by Sanjay Kanojia/AFP Photo)

Cloud inversion taken at Sunrise in Mam Tor, Derbyshire, UK on August 30, 2016. (Photo by David Zdanowicz/REX Shutterstock)

A zoo employee carries three-month-old female giant panda cub, born to mother Liang Liang and father Xing Xing, on display to the public for the first time at the national zoo in Kuala Lumpur, Malaysia, November 17, 2015. (Photo by Olivia Harris/Reuters)

Women porters load bundles onto their back for transport across the El Tarajal boarder separating Morocco and Spain's North African enclave of Ceuta, in Ceuta on December 4, 2014. Unemployment among Ceuta and Melilla's native workforce is more than 30 percent – among the highest rates in Spain. Meanwhile, authorities say some 30,000 Moroccan traders and menial workers cross into each territory every day. (Photo by Jorge Guerrero/AFP Photo)

In this January 27, 2015 photo, penguins walk on the shore of Bahia Almirantazgo in Antarctica. Antarctica “is big and it's changing and it affects the rest of the planet and we can't afford to ignore what's going on down there”, said David Vaughan, science director of the British Antarctic Survey. (Photo by Natacha Pisarenko/AP Photo)