Ark of images

A Bornean orang-utan and a Bornean/Sumatran orang-utan cross at the Houston Zoo. Photo / Joel Sartore for National Geographic

http://nationalgeographic.org/projects/photo-ark/

National Geographic has started an ambitious project to document all 12,000 species in captivity - many of which are endangered. The Photo Ark project is led by photographer Joel Sartore, whose portraits of wildlife worth saving have been projected around the world on landmarks like the Empire State Building, UN headquarters, and even the Vatican.

Giant panda at the Zoo Atlanta. Photo / Joel Sartore for National Geographic

Guianan cock of the rock at the Dallas World Aquarium. Photo / Joel Sartore for National Geographic

American flamingos at the Lincoln Children's Zoo, Nebraska. Photo / Joel Sartore for National Geographic

Green tree python at the Riverside Discovery Centre, Nebraska. Photo / Joel Sartore for National Geographic

All the images are from the April issue of National Geographic magazine.

Photo / National Geographic