This post was originally published in September 2013. We’re resurfacing it as part of our #Throwback series—which gives more love to our favorite posts. Sartore’s Photo Ark project continues, and so far he has photographed more than 5,000 species.—The Proof Team

National Geographic photographer Joel Sartore is on a mission in what may be the biggest assignment of his life. For decades Sartore has photographed some of the world’s wildest places for National Geographic, from Antarctica to the Amazon rain forest.

But Sartore didn’t feel like he was making a dent in species conservation. Eight years ago, Sartore began a project called Photo Ark, which aims to photograph the roughly 6,000 species currently inhabiting zoos around the world. Now he’s more than halfway there, at 3,050 captive species and counting.

View Images A flock of scarlet ibis (Eudocimus ruber), Caldwell Zoo, Tyler, Texas Photograph by Joel Sartore

A lot of advance work and behind-the-scenes prep happens in concert with zoo employees to ensure the animals are comfortable before he starts photographing. For each picture he installs a stark black or white background. “It allows us to get close and personal and look them in the eye,” Sartore said. “You can see details and what makes them marvelous.”

“It’s easier to photograph captive animals, because we’re pretty sure we’re going to get their picture. We can control the lighting and we know we’re not going to get skunked. But it’s harder in a sense to make an interesting picture.”

View Images A six-day-old Malayan tapir (Tapirus inducus), Minnesota Zoo Photograph by Joel Sartore

He likes to create a harmonious chaos by grouping certain animals together, like a flock of flamingos.

Among the most beautiful animals he’s photographed, Sartore said, are the birds, especially pheasants and birds of paradise. “They are absolutely stunning, with just fantastic colors,” he said.

Big cats, great apes, and bears are some of the most challenging (“they shred background material”), so he often uses latex paint that they can’t tear up.

Through the process of making these portraits, Sartore said he’s learned that animals, like us, have a range of emotions. “They have thoughts and feelings. They’re happy, mad, sometimes malicious, sometimes playful. They’re a lot like us—we’re animals too,” Sartore said. “I’ve learned they’re all important and they all count.”

Zoos are the ark now and a lot of species would already be extinct without them, Sartore said.

View Images Cecropia moth (Hyalophora cecropia), Minnesota Zoo Photograph by Joel Sartore

National Geographic Q & A with photographer Joel Sartore

National Geographic: What was the evolution of Photo Ark?

Joel Sartore: My wife was diagnosed with breast cancer nearly nine years ago. During her recovery, on the days she was feeling better, I went to the Lincoln [Nebraska] Children’s Zoo, very near my home, and started to do photos of small animals using black and white backgrounds and studio lighting. I just needed to shoot something, anything, as I’d never been “grounded” or made to stay home in all the years since starting to work for [National Geographic magazine]. The first couple species I did were a naked mole rat and a pair of poison dart frogs.

How did it expand into a bigger project?

I found that I liked the way the backgrounds gave all species equal weight and importance. Plus, I could look each creature directly in the eye, which was engaging. In time I found myself going to the zoos in Omaha, Kansas City, and Sioux Falls to do more and more portraits. The project has grown ever since.

Zoos take care of them and breed them and save them. Zoos are the keepers of the kingdom from now on. It’s important for people to support zoos financially and find out how they can volunteer their time and help zoos preserve what we have left of nature.

View Images Sand cat (Felis margarita), Chattanooga Zoo Photograph by Joel Sartore

What is the goal of Photo Ark?

The goal of all this is to simply get the public to finally wake up and pay attention. Half of all species could go extinct by the turn of the next century if we don’t stop tearing up the planet. This will be a lose-lose situation for all of us.

The species we share the Earth with are not only amazing, but very beneficial to humans. Indeed, they hold the key to our very survival. We need pollinating insects to produce fruit and vegetables. We need healthy forests to regulate our climate. So when we save other species, we’re actually saving ourselves.

But we won’t care, and certainly won’t be moved to save anything, if we don’t know these species exist, and that many are in trouble. That’s where these photos come in.

View Images Spectacled eider (Somateria fischeri), Cincinnati Zoo Photograph by Joel Sartore

How does Photo Ark inform the assignments you take on in the wild?

I try to select assignments where I can do Photo Ark shoots as well. When I covered the koala crisis in Australia, I spent a lot of time working with zoos and wildlife rehab facilities in the area as well. By combining both, I’m able to get studio shots of the animal and then go an extra step and show what is happening to the animal in the wild, whether it’s habitat loss, disease, or poaching.

View Images A five-month-old Tasmanian devil (Sarcophilus harrisii) named Mulana (which means ‘spirit’ in the aboriginal language) at Healesville Sanctuary, Australia Photograph by Joel Sartore

What are your most recent projects?

I’ve been doing nonstop Photo Ark shoots since I finished the zoos story [“Building the Ark” in National Geographic magazine’s October 2013 issue], every week now. I was in Australia two weeks ago, then Kansas, and now Grand Rapids.

What has been the greatest challenge or disappointment you have faced with this project?

That people still care more about the price at the pump and what’s on TV instead of waking up and realizing that we’re on the cusp of the biggest extinction since the dinosaurs vanished. There’s no time to lose for this project to catch fire.

What has been your greatest accomplishment with Photo Ark?

It’s the opportunity to tell the story of each and every species that I photograph. For many, this will be the only national attention they’ll ever get before they no longer exist, either in captivity or in the wild.

How can people who would like to help get involved?

People can visit photoark.com to learn more and donate to the project. They can also write to us at info@joelsartore.com. We’ve got no shortage of ideas.