Last week poachers broke into a zoo outside of Paris and shot a 4-year-old white rhino in the head before trying to hack off its horn with a chain saw.

In a world where even our zoos can’t safely protect animals threatened by extinction, people like National Geographic photographer Joel Sartore are needed more than ever.

Sartore has devoted his life to snapping every single animal species held in captivity — yes, every single one of the 12,000 creatures held in zoos and sanctuaries around the world from Tampa, Fla., to Cundinamarca, Colombia.

He has compiled the results of his efforts in a gorgeous new coffee-table book “The Photo Ark” (National Geographic), out now.

His end goal is ambitious: to build a modern-day visual ark and “halt, or at least slow, the loss of global diversity.”

Time is of the essence. Scientists estimate that every day around 200 plant and animal species go extinct. At this rate, half of Earth’s species will be extinct by 2100.

“I think of myself as an animal ambassador, a voice for the voiceless,” he writes. “If [readers] look into the eyes of these animals and see what is at stake, I’m hoping they will learn to care more and find ways that they, too, can make a difference.”

Sartore’s mission started with a naked mole rat, whom he photographed against a white background at the Lincoln Children’s Zoo a few miles from his Nebraska home in 2006. Now, more than a decade later, he has photographed 6,583 animals and counting. He estimates that the project will take 25 years to complete, but because the list of animals is ever-growing as new species are discovered and placed in captivity, he may never finish.

Each animal in his book is pictured against a stark white or black background because it “levels the playing field. The tortoise counts as much as the hare, and a mouse is every bit as magnificent as a polar bear,” he writes.

But wrangling a polar bear is not as easy as he makes it look. A cast of characters — including zookeepers, volunteers and his own trained crew — help build the backdrop, calm the animal and hide the equipment and lights from particularly anxious critters.

The result, for every specimen, shows the true beauty of our planet’s beasts.

Siamese fighting fish

(Betta splendens)

Walk into most pet stores and you’ll find a section dedicated to betta fish, one of the most popular aquarium fish in the world, bred for their aggressive temperaments. “Known for flaring their fins and fighting whenever they see another male, these fish have been bred for longer and longer fins for the pet trade,” writes photographer Sartore. This breeding for certain characteristics has led to a loss of genetic diversity in captivity and the wild. Combine this with the greater pollution and habitat loss in their native Thailand and now these fish are “vulnerable,” meaning they are on the path to becoming an endangered species.

Gang-gang cockatoo

(Callocephalon fimbriatum)

Sartore shot this male red-crowned cockatoo at Parrots in Paradise in Glass House Mountains of Australia, the bird’s native home. “[It] was part of a bird show for tourists,” Sartore tells The Post. “He was super smart and ate snacks throughout the shoot.” Like many of the smaller animals in his collection, Sartore likely shot this bird in a white cloth tent, arranging it so that the cockatoo would only see the camera lens, allowing him to shoot the bird without spooking him. The gang-gang cockatoo is beloved for its creaky birdsong that resembles a “cork being pulled from a wine bottle.” Though the gang-gang cockatoo is not endangered, the destruction of its habitat due to climate change and fire are considered serious threats to the bird’s long-term survival.

Oncilla

(Leopardus tigrinus pardinoides)

One of the smallest wild cats in South America — it weighs between 3 and 6 pounds — the oncilla or “tiger cat” is listed as “vulnerable” on the International Union for Conservation of Nature’s Red List due to deforestation and poaching (their thick, spotted coats are prized). Sartore shot this “really sweet in temperament and easy to photograph” cat at the Jaime Duque Park in Cundinamarca, Colombia. There’s so much more to learn about these majestic creatures — and their ilk. Just three years ago, scientists discovered that identical appearing oncillas located in Brazil were actually different species with different sets of genes.

Springbok mantis

(Miomantis caffra)

Beware the new girl! Though native to Southern Africa, the springbok mantis somehow made its way to New Zealand, where the females are wrecking havoc on local mantis males. Unlike New Zealand’s Orthodera novaezealandiae females, the springboks cannibalize their mates after sex. It isn’t pretty: “Females simply lunge and attack males as they get within striking distance and start consuming them immediately,” zoologist Greg Holwell told Science News. “Sometimes they start at the head; sometimes they hold them widely in both arms and start in the middle, looking like they are eating a cob of corn.”

Panther chameleons

(Furcifer pardalis)

Sartore photographed these brightly colored chameleons — the female is on top of the male, which are typically more brightly colored, an example of sexual dimorphism — at the Dallas World Aquarium in Texas. Chameleons change colors depending on the environment and the situation. When males fight, they will often change color and inflate their bodies until one backs down and returns to his dull base color. Though these animals are not officially threatened in their native Madagascar, they were exported and sold in the pet trade, dwindling their numbers in the wild.

Mexican gray wolf

(Canis lupus baileyi)

The Mexican gray wolf is the most endangered animal shown here. This gray wolf, the rare subspecies of the common wolf, once roamed wild over wide swathes of Central America, Arizona and New Mexico. But when the wolves started preying on valuable livestock, humans retaliated — nearly eradicating them from existence. Thankfully a successful recovery program commenced, and Mexican gray wolves are once again being introduced into the Blue Range Wilderness in Arizona. They remain critically endangered.

Chimpanzee

(Pan troglodytes)

By far the cutest picture of the lot, Sartore captured the humor of the baby chimp at Lowry Park Zoo in Tampa, Fla. “This baby was being raised by human moms who worked at the zoo. She refused to not be held by a human at all times, so we had to do the portrait with her caregiver holding on from the waist down, just out of frame. That made the baby feel safe, secure and even willing to ham it up a bit for the camera,” writes Sartore. Despite the cuteness of the image, the stark reality is that chimpanzees, the great apes that share 99 percent of our DNA, are endangered.