Malian workers haul out a boat they use to carry sand collected from the river bed during a routine maintenance on October 7, 2018, in the port of Bamako. Increasing construction in the Malian capital has boosted the demand for bricks made out of high-quality Niger River sand. (Photo by Michele Cattani/AFP Photo)

A picture taken on October 5, 2018, shows a general view of Migingo island which is densely populated by residents fishing mainly for Nile perch in Lake Victoria, the continent's largest lake, on the border of Uganda and Kenya. More than 500 people live on the island, which is barely 2,000-square-metres. (Photo by Yasuyoshi Chiba/AFP Photo)

A picture taken on August 7, 2017 shows a Snow Leopard (Panthera uncia) at the NABU center (Nature and Biodiversity Conservation Union), a German organization that aims at reintroducing the panther and fighting against poaching, near the Issyk Kul lake, in the outskirts of Semenovka village, some 330 kilometers southeast of Bishkek, the capital of Kyrgyzstan. (Photo by Vyacheslav Oseledko/AFP Photo)

Bangladeshi Muslims travel on the roof of an overcrowded train as they head to their hometowns ahead of Eid al-Adha in Dhaka, Bangladesh, Friday, September 1, 2017. The festival commemorates the story of Abraham and his readiness to sacrifice his son as an act of obedience to God, who provided a lamb to be used instead. (Photo by Bernat Armangue/AP Photo)

Municipal workers try to retrieve the lid of a manhole to prevent pedestrians from falling in, in Mumbai, India, Wednesday, September 20, 2017. Incessant rainfall in India's commercial capital has affected air and rail traffic, and schools and colleges remained shut for the day. (Photo by Rafiq Maqbool/AP Photo)

A woman sits on a curb at the scene of a shooting outside of a music festival along the Las Vegas Strip, Monday, October 2, 2017, in Las Vegas. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip. (Photo by John Locher/AP Photo)

The aerial view shows three uprooted trees at a road near Hildesheim, Germany Friday, October 6, 2017. Seven people died Thursday as high winds knocked over trees and caused widespread travel chaos in northern Germany. (Photo by Julian Stratenschulte/DPA via AP Photo)

A charity runner dressed as Father Christmas steps out of a portable toilet ahead of the “Santa Run” charity fun run in Stockholm on December 10, 2017. Hundreds of participants dressed in Santa suits and wearing white beards ran through the streets of the old town in Stockholm in an all charity run. (Photo by Jonathan Nackstrand/AFP Photo)