National Geographic’s December issue spotlights the world’s big cats and the dangers they face thanks to "habitat loss, illegal hunting for skins and other body parts and retaliatory killing when they prey on livestock."
"The great cats represent the ultimate test of our willingness to share this planet with other species," field biologist George B. Schaller wrote in a National Geographic essay "Politics is killing the big cats."
National Geographic photographer Vincent J. Musi spent a week at the Houston Zoo last winter to shoot a photo gallery of seven big cats to accompany the article.
Musi set up inside a small holding area on zoo grounds. He worked behind a fence, but was never more than 8 feet from the animals.
Musi’s photos are gorgeous, but the assignment was far from glamourous.
"You’re sitting, kneeling or laying down, sometimes in cat urine, for 8 to 12 hours a day. It smelled nasty! Not to mention their breath,z" Musi said.
The magazine is on newstands now.
Click here to read more about endangered big cats and see more photos.