A member of the Edo Firemanship Preservation Association displays his balancing skills atop bamboo ladder during a New Year presentation by the fire brigade in Tokyo January 6, 2015. (Photo by Thomas Peter/Reuters)

Michael Kefalianos of Australia prepares backstage prior to the pre judging for the 2012 IFBB Australian Pro Grand Prix XII at The Plenary on March 17, 2012 in Melbourne, Australia. (Photo by Robert Cianflone/Getty Images)

Edward Nunn of the USA, Toney Freeman of the USA and Dexter Jackson of the USA pose during the IFBB Australia Pro Grand Prix XII at The Plenary on March 9, 2013 in Melbourne, Australia. (Photo by Robert Cianflone)

Luke Timms of Australia poses during the pre judging of the IFBB Australian Pro Grand Prix XI at Plenary Hall on March 12, 2011 in Melbourne, Australia.

Russian oppostion activists take part in a rally and march to Bolotnaya Square on February 4, 2012 in Moscow, Russia. Demonstrators braved temperatures as low as -20 degrees celsius as they took to the streets exactly one month before the presidential elections in protest against Vladimir Putin's efforts to return to the Kremlin for an unprecedented third term as President. (Photo by: Ilya Varlamov; Source: LiveJournal)

Wedges of an orange generate enough current and electrical juice – 3.5 volts – to power an LED. The fruit’s citric acid helps electrons flow from galvanized nails to copper wire in this 14-hour exposure. This image was published in September’s Visions of Earth, a trio of photos that appear in each issue of National Geographic. (Photo by Caleb Charland/National Geographic)

This close-up image – of a Holi Festival celebrant in Vrindivan, India, coated in neon-colored powder – was submitted to National Geographic’s Your Shot in the last week of March. On April 1 we published it on our Daily News site, along with seven other bright scenes captured during the Hindu spring Festival of Colors. (Photo by Tinto Alencherry/National Geographic)

“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)