European bison, or wisents, keep a safe distance from human visitors to their enclosure on the property of Prince Richard of Sayn-Wittgenstein-Berleburg in Germany's densely populated state of North Rhine-Westphalia.
Soraya Sarhaddi Nelson /NPR
Chief Almir of Brazil's Surui tribe attends a press conference with Google representatives in Rio de Janeiro last year. Chief Almir has brought technology to his previously isolated people, who now use smartphones to send photos of illegal logging in the Amazon.
Vanderlei Almeida /AFP/Getty Images
The city of Gladstone near the Great Barrier Reef is the world's fourth largest coal-export hub. Dredges, like one seen here, have turned the harbor brown as they work to expand the coal port.