Refugees and migrants try to find a place on an already full train headed for Serbia, near the city of Gevgelija, The Former Yugoslav Republic of Macedonia, on February 24, 2016. Refugees and migrants from Iraq and Syria continue to pass through Macedonia on their way to the European Union. (Photo by Georgi Licovski/EPA)

A musher handler with Alan Eischens team embraces one of Eischen's dogs just before the ceremonial start of the Iditarod Trail Sled Dog Race that begins a near 1,000-mile (1,600-km) journey through Alaska’s frigid wilderness in downtown Anchorage, Alaska March 5, 2016. (Photo by Nathaniel Wilder/Reuters)

Kenya Wildlife Service and Save The Elephants staff push an elephant as they undertake the collaring of ten elephants ranging near the Standard Gauge Railway to fit them with advanced satellite radio tracking collars in Tsavo National Park, Kenya March 15, 2016. (Photo by Goran Tomasevic/Reuters)

A man carries an injured girl after what activists said were five air strikes by forces loyal to Syria's President Bashar al-Assad in Douma, eastern al-Ghouta, near Damascus September 11, 2014. (Photo by Bassam Khabieh/Reuters)

Participant wearing medieval costumes perform during an annual re-enactment of a battle near the village of Libusin, Czech Republic, April 23, 2016. About 2000 enthusiasts have come to simulate the medieval battle during the 24rd annual swordsmen gathering in Libusin village. (Photo by David W. Cerny/Reuters)

Tsetse, six-year-old daughter of Dukha herder Erdenebat Chuluu, sits among her family's reindeer in a forest near the village of Tsagaannuur, Khovsgol aimag, Mongolia, April 21, 2018. Nyamaa is an ethnic Darkhad, herders of northern Mongolia who have historically inhabited the steppe that borders the Taiga forests. (Photo by Thomas Peter/Reuters)

A “colacho” (a person dressed up as a devil) chases people during “El salto del Colacho”, the baby jumping festival in the village of Castrillo de Murcia, near Burgos on June 3, 2018. (Photo by Cesar Manso/AFP Photo)

A Flame Skimmer or Firecracker Skimmer dragonfly (Libellula saturata) rests on a small branch in Topanga, California, USA, 18 June 2018. The Flame Skimmer dragonfly is found in the Western United States near ponds and creeks. (Photo by Mike Nelson/EPA/EFE)