“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)

In this Wednesday, November 11, 2015 photo, one of the giant mechanical sharks that starred in the movie “Jaws” is seen at Aadlen Brothers Auto Wrecking, also known as U Pick Parts, in the Sun Valley section of Los Angeles. It's not just a junkyard or even a really big junkyard, but a living, breathing monument to Los Angeles pop culture. But the family business is closing on New Year's Eve, and everything must go by then, the cars, the shark, the arches, even the giant car-crushing machine. (Photo by Jae C. Hong/AP Photo)

Pakistani Waseem Akram, 27, dances during a private party in Rawalpindi, Pakistan. By day, Akram sells mobile phone accessories from an alleyway shop in an old neighborhood of this Pakistani city, Thursday, January 15, 2015. Across conservative Pakistan, where Islamic extremists launch near-daily attacks and many follow a strict interpretation of their Muslim faith, male cross-dressers and the transgendered face a challenge of balancing two identities. Some left their villages for the anonymity of a big city, fearing the reactions of their families while still concealing their identity from neighbors and co-workers. (Photo by Muhammed Muheisen/AP Photo)

Jorge, an immigrant from Mexico, exits a subway station dressed as the Sesame Street character Elmo in Times Square, New York July 30, 2014. Elmo and Cookie Monster have long delighted young viewers on TV's “Sesame Street”, but the recent antics of New York street performers dressed as the beloved characters have drawn the ire of city officials and now the show's producers. Sesame Workshop, which owns the rights to Big Bird, Ernie and the assorted puppet monsters on the 45-year-old program, said on July 29, 2014 it was drafting plans to stop performers who dress up as the characters from appearing in Times Square, where they pose for photos with tourists and then demand tips. (Photo by Eduardo Munoz/Reuters)

These ink-redible, explosive masterpieces are like say-what-you see inkblots tests only in water. The vibrant colors burst from Brian Tomlinsons works, appearing as though they may be coloured ash clouds from an erupting volcano, rather than simply everyday substances. By doing so, Brian challenges viewers to identify what images can be imagined when mixing one fluid with another. In order to shoot the series, entitled Liquid Ink Art, Brain, 40, drops different coloured inks into a fish tank full of water before capturing high-speed shots with a flash. Here: Brian Tomlinsons ink artwork. (Photo by Brian Tomlinsons/Caters News Agency)

Igor Shpilenok works in the reserve at Kamchatka, Russia. Igor is a fellow of the International League of Conservation Photographers and a winner of the 2006 BBC Wildlife Photographer Competition. Igor’s work has been published in numerous international and Russian magazines, including Smithsonian, National Wildlife, Geo, and BBC Wildlife.

“How does a bear behave when encounter a human? In most cases he runs away. But before running he almost always would rise to stand on his rear feet. And this behavior does not indicate the attack, as many people think...” – Igor Shpilenok. (Photo by Igor Shpilenok via Wildlife Photo Russia)

An Andean man and a woman, depicting Inca's legendary characters Manco Capac and Mama Ocllo, pose for a portrait in a Uros island at Lake Titicaca before a re-enactment in Puno November 5, 2014. The Uros islands are a group of 70 man-made totora reed islands floating on the lake, which according to Peru's tourism board iPeru is the world's highest navigable lake at over 4,000 meters above sea level. The Uros people fish and hunt, but tourism is their main source of livelihood. (Photo by Enrique Castro-Mendivil/Reuters)

Water is seen on part of the glacial ice sheet that covers about 80 percent of the country is seen on July 17, 2013 on the Glacial Ice Sheet, Greenland. As the sea levels around the globe rise, researchers affilitated with the National Science Foundation and other organizations are studying the phenomena of the melting glaciers and its long-term ramifications. The warmer temperatures that have had an effect on the glaciers in Greenland also have altered the ways in which the local populace farm, fish, hunt and even travel across land. In recent years, sea level rise in places such as Miami Beach has led to increased street flooding and prompted leaders such as New York City Mayor Michael Bloomberg to propose a $19.5 billion plan to boost the citys capacity to withstand future extreme weather events by, among other things, devising mechanisms to withstand flooding. (Photo by Joe Raedle)