“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)

Walkers cross the river Waalbrug during the first day of the 98th annual four-days walking event, the “Vierdaagse” in Nijmegen, Netherlands, July 15, 2014. The “Nijmeegse Vierdaagse” is an annual public four-day field march which is held since 1909 in the third week of July. (Photo by Erik van 't Wout/EPA)

An injured woman is pictured near the Blue Parrot nightclub in Playa del Carmen, Quintana Ro state, Mexico where 5 people were killed, three of them foreigners, during a music festival on January 16, 2017. A shooting erupted at an electronic music festival in the Mexican resort of Playa del Carmen early Monday, leaving at least five people dead and sparking a stampede, the mayor said. Fifteen people were injured, some in the stampede, after at least one shooter opened fire before dawn at the Blue Parrot nightclub during the BPM festival. (Photo by Victor Vargas/AFP Photo)

A five-week-old orphaned Southern Sea Otter pup rests on a rubber mat after arriving at the Shedd Aquarium's Abbott Oceanarium in Chicago, Illinois October 28, 2014 in this handout photo provided to Reuters on November 5, 2014. The stranded pup was found on September 30 on Coastways Beach in California and was rescued the next day to be brought back to health at the Monterey Bay Aquarium. Southern sea otters were listed as “threatened” under the U.S. Endangered Species Act in 1977. (Photo by Brenna Hernandez/Reuters/Shedd Aquarium)

In this Tuesday, January 22, 2019 photo, the wife of Saghir Khan,Anisa Khan, holds their daughter, Alfisa, at the family's house in Mirzapur. Saghir was beaten by a group of Hindus after being spotted transporting cows. (Photo by Bernat Armangue/AP Photo)

A woman with a snake on her body, taken in Rio de Janeiro, Brazil, April 2017. A holistic therapist uses snakes to massage her clients – claiming it cures depression and even helps victims of abuse. Instead of traditional massaging techniques, Sarah Zaad uses up to six pythons and boa constrictors on brave customers who want to relax or be treated for mental disorders. The flamboyant therapist from Rio de Janeiro, Brazil believes her snakes have a magic touch, which can benefit people by massaging their bodies. (Photo by Kadeh Ferreira/Barcroft Images)

A Bangladeshi girl watches from a nearby building after a five-story building was raided by police in Dhaka, Bangladesh, Tuesday, July 26, 2016. Police in Bangladesh's capital raided a five-story building Tuesday that was used as a den by suspected Islamic militants, killing nine of them, the country's police chief said. Police said they belonged to a Bangladeshi group blamed for an attack on a Dhaka cafe earlier this month in which 20 hostages, mostly foreigners, were killed and had been planning another large-scale assault. (Photo by AP Photo)

The Soyuz TMA-11M capsule with the International Space Station (ISS) crew members Japanese astronaut Koichi Wakata, Russian cosmonaut Mikhail Tyurin and U.S. astronaut Rick Mastracchio lands south-east of the town of Dzhezkazgan in central Kazakhstan, May 14, 2014. The first Japanese to command a space mission and crewmates from the United States and Russia landed safely in Kazakhstan on Wednesday, wrapping up a 188-day stay aboard the International Space Station. (Photo by Dmitry Lovetsky/Reuters)