In this October 29, 2013 photo, Daniel smokes marijuana inside his apartment where he uses a hydroponics system to grow his weed in Mexico City. “I'm not a narco, dude. I just like to smoke”, said Daniel, who spoke on condition that his last name not be used because, he said, his home-grow operation is "super-illegal" despite being for personal use only. (Photo by Eduardo Verdugo/AP 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)

Passengers travel in an overcrowded train in the eastern Indian city of Patna, February 23, 2010. (Photo by Krishna Murari Kishan/Reuters)

A Muslim dervish sings a traditional Sufi song near a rally for the Mawlid al-Nabi holiday, marking the birthday of Islam's prophet, Muhammad, in Lahore, Pakistan, Sunday, November 10, 2019. To mark the holiday, thousands take part in religious processions, ceremonies and distribute free meals to the poor. (Photo by K.M. Chaudary/AP Photo)

Tens of thousands of HIV positive prostitutes in the slums of Lagos to ensure a rapid spread of the epidemic. “If you arrive by car, you can smell the HIV virus outside”, joked my driver as we are on track to Badia a criminal slums of Lagos. Badia is a corruption of “Bad Area”. Nigerians have a lack of everything, except black humor. The poor West African country Nigeria, with a population of 140 million people, after India and South Africa the highest number of people with HIV / AIDS. (Photo by Ton Koene/Exclusivepix Media)

Vincent Yu is a multiple award winner who won Honorable Mention in the 2013 Photographer of the Year category for Pictures of the Year International. Photo: A statue of Hotei Buddha sits in the debris in the tsunami-destroyed town of Sendai, Miyagi Prefecture, northern Japan Friday, April 1, 2011. (Photo by Vincent Yu/AP Photo)

After 12 years photographing models, musicians, and celebrities, Brad Wilson decided that he wanted to photograph something a little more unpredictable: wild animals. Photo: Serval. (Photo by Brad Wilson)

Students pose for a pictures taken by their friends during spring break on the beach in the resort city of Cancun, Mexico, February 27, 2009. (Photo by Israel Leal/AP Photo)