Sandra, a 29-year-old orangutan at Buenos Aires' zoo, on May 20, 2015. Sandra got cleared to leave a Buenos Aires zoo that was her home for 20 years, after a court ruled she was entitled to more desirable living conditions. (Photo by Juan Mabromata/AFP Photo)

Children feed a giraffe at Pairi Daiza wildlife park, a zoo and botanical garden in Brugelette, Belgium, May 25, 2015. (Photo by Francois Lenoir/Reuters)

A Fulton Hotshot lights a controlled burn on the so-called “Rough Fire” in the Sequoia National Forest, California, August 21, 2015. In California, suffering its worst drought on record, about 2,500 people were forced to flee Christian camps east of Fresno at Hume Lake as the so-called Rough Fire crossed Highway 180, officials said. (Photo by Max Whittaker/Reuters)

A devotee dressed as Hindu Lord Shiva waits to participate in a parade during “Kumbh Mela” or the Pitcher Festival in Trimbakeshwar, India, August 18, 2015. The Kumbh Mela takes place four times every 12 years at four different river bank locations in India. (Photo by Danish Siddiqui/Reuters)

A monument to the character of Darth Vader from "Star Wars", which was rebuilt from a statue of Soviet state founder Vladimir Lenin, is seen in Odessa, Ukraine, October 23, 2015. The Internet Party of Ukraine's main candidate, a person named for the legendary "Star Wars" villain Darth Vader, campaigned in Odessa, cruising through town on a black van to the sound of Imperial March from "Star Wars" saga. (Photo by Yevgeny Volokin/Reuters)

A portrait of French WWI soldier Edouard Marius Ivaldi is displayed on a tablet, in this illustration picture, alongside his battlefield grave memorial, a wooden cross with a battlefield helmet in Champagne, eastern France, November 3, 2015. (Photo by Charles Platiau/Reuters)

An Indian Sikh Nihang (a traditional Sikh religious warrior) Baba 'Avtar' Singh wears an oversized giant traditional turban as he pay respects at the Golden temple in Amritsar on November 10, 2015 on the eve of the Indian festival of Diwali, the festival of lights. There will be no spectacular show of light and fireworks this Diwali at the Golden Temple as the Shiromani Gurdwara Parbandhak Committee (SGPC) has decided not to celebrate the festival in the wake of series of incidents of alleged desecration of the Guru Granth Sahib (Sikh holy book). (Photo by Narinder Nanu/AFP Photo)

A heat-stressed koala waits as a resident pours water on its back on December 19, 2015 in Adelaide, Australia. Adelaide is experiencing an extreme heatwave, with temperatures reaching over 40 degrees for five consecutive days. (Photo by Morne de Klerk/Getty Images)