National Geographic has created “Air, Land & Sea: the 50 greatest wildlife photographs” exhibition. Here: CT4 Crocodile cave on the Salamat river. Set up with Nathan Williamson last chip rain came while we were with the nomads. (Photo by Michael Nichols/National Geographic)

Volunteers try to keep alive some of the hundreds of stranded pilot whales after one of the country's largest recorded mass whale strandings, in Golden Bay, at the top of New Zealand's south island, February 10, 2017. Volunteers in New Zealand managed to refloat about 100 surviving pilot whales on Saturday, February 11, 2017 and are hoping they will swim back out to sea after more than 400 of the creatures swam aground at a remote beach. (Photo by Ross Wearing/Reuters)

This photo taken on January 30, 2020 shows officials in protective suits checking on an elderly man wearing a facemask who collapsed and died on a street near a hospital in Wuhan. AFP journalists saw the body on January 30, not long before an emergency vehicle arrived carrying police and medical staff in full-body protective suits. The World Health Organization declared a global emergency over the new coronavirus, as China reported on January 31 the death toll had climbed to 213 with nearly 10,000 infections. (Photo by Hector Retamal/AFP Photo)

Workers attach 288 new Waterford Crystal Triangles on the 2012 Times Square New Year's Eve Ball at One Times Square on December 27, 2011 in New York City. (Photo by Jason Kempin/Getty Images)

Revellers celebrate the death of Britain's former prime minister Margaret Thatcher in Brixton, south London April 8, 2013. Margaret Thatcher, the “Iron Lady” who transformed Britain and inspired conservatives around the world by radically rolling back the state during her 11 years in power, died on Monday following a stroke. She was 87. (Photo by Olivia Harris/Reuters)

Members of the Raskol gang “Dirty Dons 585”, 9 Mile Settlement, Port Moresby. All of these young men committed a set of rapes and armed robberies. The gang members admit that two thirds of their victims are women. (Photo by Vlad Sokhin)

The BMW i8 concept vehicle is displayed at a sneak preview of the car along with the BMW i3 on November 9, 2011 in New York City. (Photo by Spencer Platt/Getty Images)

A woman views the Mummy of Meresamun in the Ashmolean Museum's new exhibition of artifacts from ancient Egypt and Nubia on November 23, 2011 in Oxford, England. The new gallery is displaying for the first time in decades some of the finest Egyptian and Nubian artifacts in the UK. The Egyptian collection opens to the public from November 26, 2011. (Photo by Oli Scarff/Getty Images)