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 Pakistani scavenger girl writes on a notebook she collected from a garbage, while another girl sits next to her in Lahore, Pakistan, Wednesday, April 1, 2015. Thousands of children pick recyclable items from waste dumping points to earn living for their poor families. (Photo by K. M. Chaudary/AP Photo)

In this photo taken Saturday, January 24, 2015, a child makes a face while having her photo taken with the snow covered slopes of the Nanshan ski resort behind her in Beijing. As Beijing makes a final push in its bid for the 2022 Winter Olympics, Chinese President Xi Jinping says winning the bid will encourage over 300 million Chinese to take up winter sports by 2022, according to state-run Xinhua News agency. (Photo by Ng Han Guan/AP Photo)

A female Kurdistan Workers Party (PKK) fighter stands near a security position in Sinjar, March 13, 2015. Women fighters at a Kurdistan Workers Party (PKK) base on Mount Sinjar in northwest Iraq, just like their male counterparts, have to be ready for action at any time. Smoke from the front line, marking their battle against Islamic State, which launched an assault on northern Iraq last summer, is visible from the base. Many of the women have cut links with their families back home; the fighters come from all corners of the Kurdish region. (Photo by Asmaa Waguih /Reuters)

A Saudi soldier fires a mortar towards Houthi movement position, at the Saudi border with Yemen April 21, 2015. (Photo by Reuters/Stringer)

Members of the Gafatar sect walk in the rain as they evacuate their compound, which was later burned down by local villagers, in Antibar village, Mempawah Regency, Indonesia West Kalimantan Province, January 19, 2016 in this photo taken by Antara Foto. Local authorities and police moved the sect members to an army barracks located some 70 km (43 miles) away from Antibar for their safety following recent disputes between the sect and the villagers, Antara said on Tuesday. (Photo by Jessica Helena Wuysang/Reuters/Antara Foto)

A tourist walks inside the Ice Palace glacier hollow at Hintertux glacier, located at around 3250 meters above sea level, in Zillertal, Austria, 02 March, 2016. The hollow's temperature remains constant at 0 degrees Celsius, in summer and winter alike, and is also used by the University of Innsbruck for scientific research projects. (Photo by Lisi Niesner/EPA)

A young Indian girl dressed as Hindu goddess Laxmi participates in a procession to mark “Gudi Padwa”, or Maharashtrian New Year, in Mumbai, in the Indian state of Maharashtra, Friday, April 8, 2016. (Photo by Rajanish Kakade/AP Photo)