Two three-month-old female white Bengal tiger cubs play with a zoo keeper in their enclosure at the Buenos Aires' Zoo, in Argentina, on April 17, 2014. Captive white Bengal tiger Cloe, gave birth to three cubs – two females and one male – on January 14, 2014. (Photo by Juan Mabromata/AFP Photo)

A greater bird of paradise (Paradisaea apoda) displaying in Badigaki Forest, Wokam Island (Aru Islands, Indonesia). Found here in Aru and on adjacent New Guinea, the greater bird of paradise represents about 40 different species of birds of paradise that depend on intact rainforest across the New Guinea region spanning eastern Indonesia and Papua New Guinea. With more than 80% of forest cover still intact, this region represents the largest remaining block of rainforest in the entire Asia-Pacific. (Photo by Tim Laman/naturepl.com/LDY Agency)

A golden huddle by Minqiang Lu, China. Two females and a male golden snub-nosed monkey huddle together to keep warm in the extreme cold. Threatened by forest loss and fragmentation, this endangered species is confined to central China. Restricted to living high up in the temperate forests, these monkeys – here in the Qinling mountains in Shaanxi province – feed mostly in the trees, on leaves, bark, buds and lichen. In heavy wind and snow, Minqiang walked up the mountain carrying his equipment. He stayed for half an hour in temperatures of –10C opposite the tree where the group was huddled before achieving this eye-level composition. (Photo by Minqiang Lu/Wildlife Photographer of the Year)

Indian commuters travel in a local train in Kolkata, India, Tuesday, February 26, 2013. Indian Railway Minister Pawan Kumar Bansal is presenting the country's rail budget for next fiscal year in the parliament Tuesday, Feb. 26, 2013. Indian railway network is one of the world's largest, with some 14 million passengers daily and some 64,000 kilometers (40,000 miles) of railway track cut through some of the most densely populated cities. (Photo by Bikas Das/AP Photo)

Heather Larsen from Golden, Colorado, USA performs a split while walking the slackfline or highline across two towers in the Tower of David citadel complex overlooking the Old City of Jerusalem 02 May 2016. Larsen is one of the world's top female highliners, or slack liners and walked the lines as part of a Kickstarter campaign for an outdoor product. The tower at left was built by King King Herod some 2000 years ago. (Photo by Jim Hollander/EPA)

A woman tries to protect her daughter as refugees scuffle with the Greek police in their effort to reach the borderline with Macedonia, near the Greek village of Idomeni, Sunday, November 22, 2015. Over 1,000 migrants gathered in the Greek town Idomeni protested Saturday against the decision by Macedonian authorities across the border to turn away migrants who are not from war zones such as Syria, Afghanistan and Iraq. (Photo by Giannis Papanikos/AP Photo)

A Filipino flagellant crawls along a street on Maundy Thursday, in San Fernando city, Pampanga Province, north of Manila, Philippines, 24 March 2016. Many Filipino Catholic penitents mark the Holy Week by submitting to different forms of physical penance in the hopes of being forgiven for their sins. (Photo by Francis R. Malasig/EPA)

An India Christian devotee reenacts the sufferings of Jesus Christ on the occasion of Good Friday in Mumbai, India, Friday, March 29, 2013. Christians all over the world are marking Good Friday, the day when Christ was crucified. (Photo by Rajanish Kakade/AP Photo)