“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)

Iraqi Kurdish refugees wait with children in Cukurca refugee camp in Turkey April 8, 1991. Reuters photographers have chronicled Kurdish refugee crises over the years. In 1991 Srdjan Zivulovic documented refugees in Cukurca who had escaped a military operation by Saddam Hussein's government in Iraq aimed at “Arabising” Kurdish areas in the north. Hundreds of thousands fled into Turkey and Iran. Images shot in recent months show familiar scenes as crowds of people flee Islamic State militants in Syria. There are as many as 30 million Kurds, spread through Turkey, Iraq, Syria and Iran. Most Kurds are Sunni Muslims, but tend to feel more loyalty to their Kurdishness, rather than their religion. (Photo by Srdjan Zivulovic/Reuters)

A woman poses next to a giant mining truck at the entrance of the Dakar Rally camp in Calama, Chile. The truck operates in copper mines near the city. (Photo by Victor R. Caivano/Associated Press)

A motorcycle Majestic 350 CC 1931 is displayed on February 5, 2014 at the Grand Palais in Paris on the eve of an auction of luxury vintage cars. (Photo by Francois Guillot/AFP Photo)

“The Independence day”. While on storm chasing expeditions in the Tornado Alley in USA I have encountered many photogenic supercell storms. This photograph was taken while we were approaching the storm near Julesburg, Colorado on My 28th, 2013. The storm was tornado warned for more than one hour, but stayed an LP storm through all its cycles and never produced a tornado, just occasional brief funnels, large hail and some rain. Photo location: Julesburg, Colorado, USA. (Photo and caption by Marko Korošec/National Geographic Photo Contest)

The jewelled flower mantis, commonly found in Asia, is believed to be the inspiration for many martial artists is seen in Jakarta, Indonesia on August 2, 2016. (Photo by Prabu Dennaga/Barcroft Images)

The northern lights, or aurora borealis, appear in the sky over the Bamburgh lighthouse at Stag Rock in Northumberland, England on September 28, 2016. (Photo by Owen Humphreys/PA Wire via ZUMA Press)

Performers take part in a rain soaked Notting Hill Carnival on August 25th, 2014 in London, England. Despite the bad weather over 1 million visitors are expected to attend the two-day event which is the largest of its kind in Europe. The event has taken place on the West London streets every August Bank Holiday weekend since 1964. (Photo by Mary Turner/Getty Images)