Waura Indians wrestle during 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, Brazil August 25, 2013. (Photo by Ueslei Marcelino/Reuters)

Thousands of species of amphibians are endangered and hundreds have already disappeared, but in recent years, a team of scientists and conservationists have re-discovered some of these “lost” species and uncovered previously unknown varieties. Here: Miniature glass frog. (Photo by Robin Moore)

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)

Fisherwomen laying barrels with salt in preparation for herring curing, 1937. (Photo by Topical Press Agency)

This photo of an elephant seal and Gentoo penguin shot by Andrew James in Yankee Harbour, Antarctica. (Photo by Andrew James/Travel Photographer of the Year)

A woman sits in a cell at the Los Angeles County Women's jail in Lynwood, California April 26, 2013. (Photo by Lucy Nicholson/Reuters)

Tribal artists and supporters from the southern Indian state of Karnataka dance outside the residence of Congress Party President Sonia Gandhi during her birthday celebrations in New Delhi, India, Wednesday, December 9, 2015. The Italian-born Gandhi is the widow of former Prime Minister Rajiv Gandhi and has led the Congress party since 1998. (Photo by Altaf Qadri/AP Photo)

Palestinian children warm themselves by a fire on a stormy day at Shati (beach) refugee camp in Gaza City January 18, 2016. (Photo by Mohammed Salem/Reuters)