Since 2006, the annual assessment of the planet's imperiled wildlife has grown by more than a thousand species and now totals 41,415.

Many great apes end up on the list, as their habitat is continually under threat from human activities. (Read about the charcoal trade and Congo's mountain gorillas.)

Western lowland gorilla populations in central Africa have collapsed due to the commercial bushmeat trade and the Ebola virus. And in Indonesia, orangutans are critically endangered because of forest logging and clearing land for palm oil plantations.

• More Photos in the News
• Today's Top 15 Most Popular Stories
• Free Email Newsletter: "Focus on Photography"