In this photo taken Friday, September 4, 2015, tourists Sarah and John Scott from Worcester, England, take a step back as a male silverback mountain gorilla from the family of mountain gorillas named Amahoro, which means “peace” in the Rwandan language, unexpectedly steps out from the bush to cross their path in the dense forest on the slopes of Mount Bisoke volcano in Volcanoes National Park, northern Rwanda. Deep in Rwanda's steep-sloped forest, increasing numbers of tourists are heading to see the mountain gorillas, a subspecies whose total population is an estimated 900 and who also live in neighboring Uganda and Congo, fueling an industry seen as key to the welfare of the critically endangered species as well as Rwanda's economy. (Photo by Ben Curtis/AP Photo)

Sasha Muir and Margaret Davidson sit in a car as some of the 30 barbary macaques, known as the Middle Hill Troop after living between the top of Gibraltar rock and the town, show what happens when motorists forget to lock their luggage compartments, as Scotland’s only monkey drive-through section opens at Blair Drummond safari park in Stirling, Scotland on October 8, 2015. (Photo by Andrew Milligan/PA Wire)

A member of the “Los Danzantes y Los Boteiros” folk group performs during the parade of the 10th International Festival of the Iberian Mask in Lisbon, Portugal May 9, 2015. The festival runs until next Sunday and about 690 masked people from Spain and Portugal are participating, according to organizers. (Photo by Rafael Marchante/Reuters)

An Afghan man is carried out of a hospital after receiving treatment following a suicide truck bomb attack in Kabul, Afghanistan August 7, 2015. The bombings were the first in Kabul since Mullah Akhtar Mansour took charge of the Taliban last week, and followed a rare truck bomb attack in an eastern province on Thursday. (Photo by Omar Sobhani/Reuters)

A cat dressed in a traditional Ukrainian embroidered shirt takes part in a parade in Kiev, Ukraine on May 28, 2016. (Photo by Gleb Garanich/Reuters)

A flood affected family moves on a banana raft past a fishing net in Morigaon district, east of Gauhati, northeastern Assam state, India, Sunday, July 31, 2016. A week of heavy rain has killed dozens of people and uprooted tens of thousands of others from their homes. Floods are an annual occurrence in Assam and many parts of India during the June-September monsoon season. (Photo by Anupam Nath/AP Photo)

A Santa Claus puppet holding a Christmas tree is pictured against the sun in Berlin November 23, 2014. (Photo by Hannibal Hanschke/Reuters)

A riot policeman uses a baton to hit a rioting University of Nairobi student in Kenya's capital Nairobi, in this May 20, 2014 file photo. (Photo by Noor Khamis/Reuters)