Young U.S. visitors pose for a photograph next to a vintage car in Havana March 16, 2016. (Photo by Ueslei Marcelino/Reuters)

“Cassowaries are large, flightless birds related to emus and (more distantly) to ostriches, rheas, and kiwis”, writes Olivia Judson in the September issue of National Geographic magazine. How large? People-size: Adult males stand well over five foot five and top 110 pounds. Females are even taller, and can weigh more than 160 pounds. Dangerous when roused, they’re shy and peaceable when left alone. But even birds this big and tough are prey to habitat loss. The dense New Guinea and Australia rain forests where they live have dwindled. Today cassowaries might number 1,500 to 2,000. And because they help shape those same forests – by moving seeds from one place to another – “if they vanish”, Judson writes, “the structure of the forest would gradually change” too. (Photo by Christian Ziegler/National Geographic)

Two men ride a motorcycle away from a fire in Athens on Friday, July 17, 2015. Greek firefighters battled large brush and forest fires on the outskirts of Athens and in the country's southern Peloponnese region Friday, where flames forced the evacuation of at least three villages and two summer camps. (Photo by Giorgos Bamboukos/InTime News via AP Photo)

A boy uses remnants of ordnance as he prepares dough inside Abu Khaled's shop in the Douma neighborhood of Damascus April 28, 2015. Abu Khaled opened a shop for making “barley bread” using remnants of weapons including rockets, tank shells and other ordnance fired by forces loyal to Syria's President Bashar al-Assad. (Photo by Amer Almohibany/Reuters)

A Thai policeman patrols around a bar area in central Bangkok, Thailand, August 19, 2015. Thai police on Wednesday issued an arrest warrant for an individual they described as a “foreign man”, in connection with a bomb blast in Bangkok that killed 20 people, including many foreigners. (Photo by Kerek Wongsa/Reuters)

A man dressed as Hindu Lord Shiva looks into the mirror as he gets ready to take part in a religious procession on the eve of Janmashtami festival in Amritsar, India, September 4, 2015. The festival, which marks the birth anniversary of Lord Krishna, will be celebrated across India on Saturday. (Photo by Munish Sharma/Reuters)

Alpine Skiing, FIS Alpine Skiing World Cup, Men's Parallel Giant Slalom, Alta Badia, Italy on December 19, 2016. Hostesses take a bath in a Jacuzzi pool during the race. (Photo by Stefano Rellandini/Reuters)

A horse named Quinn, with a skeleton painted on it to help educate officers, is pictured during a visit by Britain's Queen Elizabeth II (unseen) and Britain's Prince Charles, Prince of Wales (unseen) to the Household Cavalry Mounted Regiment at the Hyde Park Barracks in west London on October 24, 2017. (Photo by Chris Jackson/AFP Photo)