Tanzania, 1964. A touching moment between primatologist and National Geographic grantee Jane Goodall and young chimpanzee Flint at Tanzania's Gombe Stream Reserve. (Photo by Hugo van Lawick via National Geographic)

Two stallions confront each other at a horse fighting contest in Rongshui, China. More than 30 horses from surrounding regions took part in the traditional activity of the Lantern festival. (Photo by China Foto Press)

Four-year-old Solaris Arias (right) jumps through water spraying from an open fire hydrant in Providence, Rhode Island, on June 20, 2012. Much of the state remained under a heat advisory Tuesday afternoon because of the steamy air mass that has moved into the region resulting in temperatures in the 90s. (Photo by Steven Senne/AP Photo)

A Russian-made rifle, carried by this woman when she was captured in Nearby Brush, is slung around her neck by South Vietnamese soldiers before they began their interrogation of her as Viet Cong suspect near AP La Ghi in Vietnam, August 25, 1965. The girl behind the woman, also was captured in the brush. (Photo by AP Photo)

A model train travels past a scaled model of New York's Grand Central Station built entirely with plant parts during a media preview of the 25th annual Holiday Train Show at the New York Botanical Garden in the Bronx borough of New York City, U.S., November 14, 2016. (Photo by Mike Segar/Reuters)

Female soldiers march in formation in St Petersburg' s Palace Square during a rehearsal of a Victory Day military parade marking the 72 nd anniversary of the victory over Nazi Germany in the 1941-1945 Great Patriotic War, the Eastern Front of World War II, on May 5, 2017. (Photo by Peter Kovalev/TASS)

A baby tamandua, or anteater, named Poco sticks out its tongue on May 31, 2018. ZSL London Zoo is celebrating the creature’s surprise birth after they found a male to be the companion of its mother Ria last October. (Photo by ZSL London Zoo/PA Wire)

Farmer Ash Whitney stands in the middle of a dried-up dam in a drought-effected paddock on his property located west of the town of Gunnedah in New South Wales, Australia, June 3, 2018. “I have been here all my life, and this drought is feeling like it will be around a while”, said Whitney. (Photo by David Gray/Reuters)