People take photos as an Ariane 5 space rocket with a payload of four Galileo satellites lifts off from ESA's European Spaceport in Kourou, French Guiana, on November 17, 2016. Ariane 5 successfully launched on November 17 four satellites which will be part of the Galileo global satellite navigation system. (Photo by Jody Amiet/AFP Photo)

An employee of a bakery talks on his mobile while balancing on his head a tray of freshly baked bread from a local bakery in a street in Cairo, Egypt, January 12, 2016. (Photo by Asmaa Waguih/Reuters)

Crews move a 39 foot long, 16 foot tall, 2400 lbs. replica of a Tyrannosaurus Rex from behind the Museum Of Science And History in Jacksonville, Fla., to its new location in front of the entrance of the museum Wednesday morning, May 20, 2015, to kickoff the upcoming Dinosaurs Unearthed exhibit. The exhibiti, which opens this week, includes animatronic dinosaurs as well as prehistoric fossils and runs through September 7. (Photo by Bob Self/The Florida Times-Union via AP Photo)

“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)

Beachgoers watch the detonation of a 500 pound British bomb on the beach on May 19, 2014 in Wassenaar, Netherlands. The bomb was dropped by the British allied forces during the second world war over nearby Leiden where it was found on a building site. (Photo by Michel Porro/Getty Images)

White lioness Azira lies in the cage with her three white cubs, on February 4, 2014. Zoo owner Andrzej Pabich says white lions often have defects that prevent giving birth, or the mother rejects her cubs, but Azira has been patiently feeding and caring for her little ones. (Photo by Czarek Sokolowski/Associated Press)

Revellers pose during the 24th Street Parade dance music event in Zurich, August 29, 2015. (Photo by Arnd Wiegmann/Reuters)

A twelve foot long giant hamster has surprised Londoners along the South Bank, Millennium Bridge and Clapham Common on May 26, 2016. A 4-metre pedal-powered mechanical model hamster, which has been created in the likeness of Jaffa the hamster, who is listed as one of the 10 oddest discoveries made by Kwik Fit technicians in customers’ cars. (Photo by Joe Pepler/Rex Features/Shutterstock)