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 woman looks at head of bluefin tuna on display in front of a store at Tsukiji fish market in Tokyo, Monday, February 19, 2018. The large bluefin are particularly valuable in Japan, where they are considered a premium sushi and sashimi fish. A single fish sold for more than $1.75 million at an auction in Japan in 2013. (Photo by Koji Sasahara/AP Photo)

From the “Paradise Revisited” story in the November 2013 issue of National Geographic magazine, this image is a beautiful vision of father and son fishermen as they move through the multicolored coral gardens of Kembe Bay, Papua New Guinea, in a traditional outrigger canoe. (Photo by David Doubilet/National Geographic Creative)

An Israeli soldier of the Caracal battalion smiles during a 23-kilometer march marking the end of their training in Israel's Negev desert, near Kibbutz Sde Boker February 14, 2013. The “Caracal” battalion, two-thirds of whose members are women, was established in 2004 with the purpose of incorporating female soldiers in combat units. The main mission of Caracal is routine patrols on Israel's border with Egypt to intercept infiltrators and smuggling from the Sinai desert. (Photo by Darren Whiteside/Reuters)

A freediver uses weights, yoga and camera tricks to create the illusion of walking underwater for a film which took three years to shoot and was completed in 2013 in El Hierro, Canary Islands. Like a scene from a Hollywood science-fiction movie, this trick footage shows a man apparently walking on water. The underwater film was shot by biologist Armiche Ramos and brothers Armando and Francisco del Rosario, who used their expertise in freediving to create the illusion. No computer graphics were involved in the production, with the team relying solely on their own skills – and a few hidden secrets. (Photo by Ocean Brothers/Barcroft Media/ABACAPress)

A Waura Indian woman watches the activities of this year's “quarup”, a ritual held over several days to honour in death a person of great importance to them, in Xingu National Park, Mato Grosso State, August 24, 2013. This year the Waura tribe is honouring their late cacique (chief) Atamai, who died in 2012 and helped created the Xingu Park, and his important contribution in facilitating communication between white Brazilians and Indians. (Photo by Ueslei Marcelino/Reuters)

This handout picture taken by Pleiades satellite and released on September 27, 2013 shows a small island of mud and rock created by the huge earthquake that hit southwest Pakistan has fascinated locals but experts – who found methane gas rising from it – say it is unlikely to last long. The 7.7-magnitude quake struck on September 25 in Baluchistan's remote Awaran district, killing at least 271 people and affecting hundreds of thousands. The island is about 60 to 70 feet (18 to 21 metres) high, up to 300 feet wide and up to 120 feet long and sits about 650 feet from the coast. (Photo by AFP Photo/CNES/Distribution Astrium Services)

An Indian villager braving strong winds and rain walk to a safer place, in village Podampeta, in Ganjam district about 200 kilometers (125 miles) from the eastern Indian city Bhubaneswar, India, Saturday, October 12, 2013. Strong winds and heavy rains pounded India's eastern coastline Saturday, as hundreds of thousands of people took shelter from a massive, powerful Cyclone Phailin expected to reach land in a few hours. (Photo by Biswaranjan Rout/AP Photo)