Female Chimpanzee “Fifi” eats carrots as she sits in her enclosure at Taronga Zoo on her 60th birthday May 21, 2007 in Sydney, Australia. Fifi is the oldest of the Zoo's chimp population, which consists of 19 individuals. (Photo by Ian Waldie/Getty Images)

Iraqi women cry over their brother's body, who was killed by a mortar shell fired by Islamic State (IS) group jihadists on civilians who were gathered to receive aid, in Al-Risala neighbourhood on March 22, 2017, as an ongoing offensive by Iraqi forces to retake the city from the group continues. Iraqi forces launched a major operation to recapture west Mosul – the most-populated urban area still held by IS – on February 19, and have retaken a series of neighbourhoods from the jihadists. (Photo by Ahmad Al-Rubaye/AFP Photo)

Sheep are herded during the annual sheep parade through Madrid November 2, 2014. Shepherds parade the sheep through the city every year in order to exercise their right to use traditional routes to migrate their livestock from northern Spain to winter grazing pasture land in southern Spain. (Photo by Susana Vera/Reuters)

A tiger cub has a short chat with a chimp. (Photo by Ian Tyas/Keystone Features/Getty Images). 27th November 1979

Young gymnasts practice pull-up on a bar at a gymnasium of a sports school in Jiaxing, Zhejiang province April 11, 2015. (Photo by William Hong/Reuters)

Children react after what activists said was shelling by forces loyal to Syria's President Bashar al-Assad near the Syrian Arab Red Crescent center in the Douma neighborhood of Damascus May 6, 2015. (Photo by Bassam Khabieh/Reuters)

An Indian Sikh devotee spits fire as he performs during religious procession ahead of the birth anniversary of the first Sikh Guru or master, Sri Guru Nanak Dev Ji, the founder of Sikhism, in Jammu, the winter capital of Kashmir, India, 21 November 2018. The birth anniversary of Guru Nanak Dev Ji will be observed on 23 November 2018. (Photo by Jaipal Singh/EPA/EFE)

Harris & Ewing Inc. photographed people, events, and architecture, particularly in Washington, D.C., during the period 1905-1945. Photo: Tests of Curtiss Palne for Army, Single Control. Created by Harris & Ewing. Published in 1912.