Supporters of incumbent President Mahamadou Issoufou attend a campaign rally in Niamey, Niger, February 18, 2016. Niger holds presidential and legislative elections on Sunday. (Photo by Joe Penney/Reuters)

A 6-month old female giant panda cub, an offspring of Xing Xing, formerly known as Fu Wa and Liang Liang, formerly known as Feng Yi, plays at the Giant Panda Conservation Center at the National Zoo in Kuala Lumpur, Malaysia, Thursday, February 18, 2016. (Photo by Joshua Paul/AP Photo)

A Sri Lankan leopard is pictured at a zoo in Dehiwala near Colombo on March 3, 2016, on World Wildlife Day. (Photo by Ishara S. Kodikara/AFP Photo)

Women take part in a rally called “March of Whores” to protest against discrimination and violence against women on International Women's Day in Bogota, Colombia, March 8, 2016. (Photo by John Vizcaino/Reuters)

Photo taken on September 19, 2015 shows a baby Brazilian opossum at the “Parque Estoril” zoo in Sao Bernardo do Campo of Sao Paulo, Brazil. According to local press, the “Parque Estoril” zoo houses currently 23 orphan cubs of wild animals rescued in the south region of Sao Paulo, victims of illegal wildlife trade or problems caused by urban growth. According to the zoo, all the animals arrived in the last three months, and many of them, not being able to be reintroduced to their natural habitat, will be used as examples in environmental education classes. (Photo by Rahel Patrasso/Xinhua via ZUMA Wire)

Sasha Muir and Margaret Davidson sit in a car as some of the 30 barbary macaques, known as the Middle Hill Troop after living between the top of Gibraltar rock and the town, show what happens when motorists forget to lock their luggage compartments, as Scotland’s only monkey drive-through section opens at Blair Drummond safari park in Stirling, Scotland on October 8, 2015. (Photo by Andrew Milligan/PA Wire)

Women practice yoga during a performance on a glass bridge at the Shiniuzhai National Geo-park in Pingjiang county, Hunan province, China, November 5, 2015. About hundred yoga fans put on the show to promote the concept of green life and the idea of harmony between human and nature on Thursday, according to local media. (Photo by Reuters/China Daily)

Tourists feed freshly picked grapes to 40-year-old elephant Boonruen, a long-term resident of the Hua Hin Hills vineyard, that used to be an elephant corral in Hua Hin, about 200km southwest of Bangkok, Thailand, 08 March 2016. The winery is among a handful of companies producing new latitude wines in non-traditional wine areas of the world near the equator. Harvest is only once a year in Thailand, this year in March. (Photo by Barbara Walton/EPA)