Giraffes cross under the bridge of the Standard Gauge Railway (SGR) line inside the Nairobi National Park in Nairobi, Kenya, May 25, 2020. (Photo by Baz Ratner/Reuters)

Military Personnel sing and dance during celebrations for Independence Day in Dakar on April 4, 2022. Senegal Celebrates its sixty second Independence Day after gaining independence from France in 1960. (Photo by John Wessels/AFP Photo)

Firefighters watch as an air tanker drops retardant while battling the Ferguson fire in the Stanislaus National Forest, near Yosemite National Park, California on July 21, 2018. A fire that claimed the life of one firefighter and injured two others near California's Yosemite national park has almost doubled in size in three days, authorities said Friday. (Photo by Noah Berger/AFP Photo)

American model Kaia Gerber wears a creation as part of the Prada Fall/Winter 2022-2023 fashion collection, unveiled during the Fashion Week in Milan, Italy, Thursday, February 24, 2022. (Photo by Luca Bruno/AP Photo)

A wild elephant eats garbage containing plastic waste at a dump in Sri Lanka's eastern district of Ampara on June 3, 2023. Sri Lanka is set to launch a nation-wide clean up of plastic waste ahead of new laws banning the sale of single use plastics, the Environmental ministry said, after a spate of deaths of elephants and deer in the island's northeast after foraging at open garbage tips filled with plastic waste, whilst shrinking habitat has led to jumbos raiding villages looking for food. (Photo by Ishara S. Kodikara/AFP Photo)

Expedition 44 flight engineer and NASA astronaut Scott Kelly seen inside the Cupola, a special module which provides a 360-degree viewing of the Earth and the International Space Station. Kelly is one of two crew members spending an entire year in space. (Photo by Scott Kelly/NASA)

Heidi Klum attends the Heidi Klum's 16th Annual Halloween Party sponsored by GSN's Hellevator And SVEDKA Vodka At LAVO New York on October 31, 2015 in New York City. (Photo by Mike Coppola/Getty Images for Heidi Klum)

“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)