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)

In this Friday, February 6, 2015 photo, sandhill cranes begin to stir after resting for the night at a roosting location along their winter migration route in Cecilia, Ky. According to counts made by biologists with the Kentucky Fish and Wildlife Resources, about 12,000 of the birds have stopped in Cecilia this week during their winter northward migration on their way to their nesting grounds in the Great Lakes region. (Photo by David Stephenson/AP Photo)

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)

An actor plays an injured passer-by during Exercise Strong Tower, the scene of a mock terror attack at a disused underground station in central London, Britain June 30, 2015. London police held their biggest-ever terrorism drill on Tuesday, pitting the emergency services against a group of marauding attackers, nearly 10 years since four young British Islamists killed 52 people in suicide bombings on London's transport network in July 2005. (Photo by Peter Nicholls/Reuters)

Long shadows are cast by players as Mitch Wallis of the Bulldogs passes the ball during the 2016 AFL Round 08 match between the Melbourne Demons and the Western Bulldogs at the Melbourne Cricket Ground, Melbourne on May 15, 2016. (Photo by Scott Barbour/AFL Media/Getty Images)

A policewoman reacts as she falls off from a motorcycle while taking part in a rehearsal for Independence Day celebrations, in Ahmedabad, India August 4, 2017. (Photo by Amit Dave/Reuters)

Thailand’s Sanctuary of Truth is an all-wood building filled with sculptures based on traditional Buddhist and Hindu motifs. It is covered in intricate wood carvings, meant to depict complex ideas about ancient thought, human responsibility, and the cycle of life. (Photo by Yury Taranik/Getty Inages)