A greater bird of paradise (Paradisaea apoda) displaying in Badigaki Forest, Wokam Island (Aru Islands, Indonesia). Found here in Aru and on adjacent New Guinea, the greater bird of paradise represents about 40 different species of birds of paradise that depend on intact rainforest across the New Guinea region spanning eastern Indonesia and Papua New Guinea. With more than 80% of forest cover still intact, this region represents the largest remaining block of rainforest in the entire Asia-Pacific. (Photo by Tim Laman/naturepl.com/LDY Agency)

Indonesian residents look at the Mount Sinabung volcano as it spews volcanic ash near the Tiga Pancur village in Karo, North Sumatra on August 3, 2016. Volcanic eruptions in Indonesia in recent days have forced the closure of two airports and disrupted some flights to the holiday island of Bali, officials said August 3. Mount Sinabung, a volcano on the western island of Sumatra which has been rumbling for some time, also erupted violently on August 2, although its ash clouds did not disrupt any flights. (Photo by Y.T. Haryono/AFP 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)

“Double head vulture”. On the day of windy days during raptors migration some people in my country start to catch these tired raptors, so in this day we go to photograph some raptors and we saw these tow tired vultures, so we start to drag them away from the hunters until they reach a good hidden place, to make them safe until they start a new journey. Photo location: Kuwait. (Photo and caption by Mohd Khorshed/National Geographic Photo Contest)

Arctic wolves in their new enclosure in the wildlife park in Hanau, Germany, 10 February 2015. The pack is one of the park's main attractions, which specializes in local and European breeds. (Photo by Boris Roessler/EPA)

A wax figure of U.S. actress Scarlett Johansson stands outside Madame Tussauds New York attraction shortly after the figure was unveiled in Times Square in New York, July 30, 2015. (Photo by Mike Segar/Reuters)

In this Thursday, December 1, 2016 photo, Cat Bigney, part of the Oglala Native American tribe, waits on the shore of the Cannonball river for travelers to arrive by canoe at the Oceti Sakowin camp where people have gathered to protest the Dakota Access oil pipeline in Cannon Ball, N.D. So far, those at the camp have shrugged off the heavy snow, icy winds and frigid temperatures. But if they defy next week's government deadline to abandon the camp, demonstrators know the real deep freeze lies ahead. Life-threatening wind chills and towering snow drifts could mean the greatest challenge is simple survival. (Photo by David Goldman/AP Photo)

A shoebill is displayed at Ueno Zoo in Tokyo August 28, 2012. (Photo by Itsuo Inouye/Associated Press)