Singer/Songwriter Chris Janson (center black shirt) with fans during Country Thunder USA – Day 3 on April 11, 2015 in Florence, Arizona. (Photo by Rick Diamond/Getty Images for Country Thunder USA)

“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)

Britain Horse Racing, Royal Ascot, Ascot Racecourse on June 14, 2016. Racegoers in Britain and EU referendum themed dresses. (Photo by Toby Melville/Reuters/Livepic)

An artist's impression of a growing supermassive black hole located in the early Universe is seen in this NASA handout illustration released on June 15, 2011. Using the deepest X-ray image ever taken, astronomers found the first direct evidence that massive black holes were common in the early universe. This discovery from NASA's Chandra X-Ray Observatory shows that very young black holes grew more aggressively than previously thought, in tandem with the growth of their host galaxies. (Photo by Reuters/NASA/Chandra X-Ray Observatory/A.Hobart)

The sculpture “It Takes Two to Tango” by Scottish sculptor David Mach is seen in front of the headquarters of the CMA-CGM shipping company office tower in the port of Marseille, France, March 15, 2016. (Photo by Jean-Paul Pelissier/Reuters)

An Indian Sikh devotee takes a dip in the holy sarover (water tank) at the Golden Temple on the eve of “Ghallughara Diwas”, the 29th Anniversary of Operation Bluestar, in Amritsar on June 5, 2013. The 1984 assault on the Golden Temple complex by the Indian army was conducted in an attempt to arrest separatists Sikh leader Sant Jarnail Singh Bhindranwale and his militant followers who had initiated a movement for a separate Sikh state. (Photo by Narinder Nanu/AFP Photo)

A woman is consoled by her relative as she mourns after seeing her house getting burned during a fire that broke out in one of the houses and got spread in more adjoining houses, in a residential locality in Srinagar, November 21, 2016. (Photo by Danish Ismail/Reuters)

Dancers prepare before a performance in the backstage area of the Buick exhibition during the “Auto China 2014” Beijing International Automotive Exhibition in Beijing on April 21, 2014. Leading automakers have gathered in Beijing for the kickoff of China's biggest car show, but lackluster growth and environmental restrictions in the world's largest car market have thrown uncertainty into the mix. (Photo by AFP Photo)