“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)

Elephants spray tourists with water in celebration of the Songkran water festival in Thailand's Ayutthaya province, about 80 km (50 miles) north of Bangkok, April 9, 2014. (Photo by Rungroj Yongrit/EFE)

A Japanese white-eye is seen on a branch of cherry blossoms at Kyoto Imperial Palace on March 26, 2010 in Kyoto, Japan. (Photo by Akihiro I/Getty Images)

A member of the Eton public school O.T.C. (Officers Training Corps) practising shouting out orders during a training session, 20th January 1940. (Photo by Hulton Archive/Getty Images)

The European Football Championship will take place in Donetsk 2012. The city is currently home to two major professional football teams in Ukraine: Shakhtar Donetsk and Metalurh Donetsk, both of which currently play in the Ukrainian Premier League. (Photo by: LancerenoK; Source: Flickr)

A fruit importer's lorry at Covent Garden, London, with its driver's cabin in the shape of an apple. (Photo by Harold Clements/London Express/Getty Images). October 1928

A Chinese man made up like “Wutu” which means tiger in ancient time, dances during an annual exorcism ceremony of the local Tu ethnic minority group at Nianduhu Village on December 31, 2004 in Tongren County, northwest of China. (Photo by China Photos/Getty Images)

Indian soldiers practice their stunts on Royal Enfield motorcycles in preparation for the upcoming Republic Day parade on January 11, 2012 in New Delhi, India. (Photo by Daniel Berehulak /Getty Images)