The species was unknown to European scientists until a century ago. It is thought to have inspired claims of unicorn sightings by Victorian-era explorers, said Noelle Kumpel, a conservationist with the Zoological Society of London, which released the photos.
The male has two horns on its forehead, but they can look like one horn if glimpsed from the side. "Stories came back of this mythical creature and the fact that it might be a unicorn," Kumpel said.
The photos were taken by cameras set up in the Virunga National Park by the zoological society and conservationists in Congo after okapi tracks were spotted there a few years ago.
The animal's stripes are sometimes called "come follow me stripes," because their bold pattern is believed to help young ones follow their mothers through the forest. Each animal's stripes are unique, like fingerprints.
The okapi is only known to exist in Congo, primarily further north in Ituri provinces's Okapi Wildlife Reserve. There, they are difficult to spot because they are shy and usually only move around in couples. Virunga officials say before the okapi was captured on camera, it was not known whether it still roamed Virunga.
"We are encouraged by the evidence that okapis have survived in Virunga, despite the years of conflict," Virunga National Park Director Emmanuel de Merode said in an e-mailed statement to The Associated Press. "Park rangers have only recently regained control of this area that was formerly occupied by armed militias. But while it is positive that the okapi population remains, we are aware of their vulnerability to intense levels of poaching."
The photos also indicate the animals are more widely distributed in the park than was previously believed.
"We've managed to get pictures of three separate individuals, and we've also got a picture of one roaming around at nighttime and actually foraging, which is the first evidence of this behavior," said Kumpel. Scientists previously believed okapi fed only during the day, she said.
Virunga, near the Rwanda and Uganda borders, is also home to some of the world's last remaining mountain gorillas. Part of the reserve is still occupied by Congolese and Rwandan rebels, who have hidden in its dense forests for more than a decade and used parts of it as bases to launch attacks.
The reserve is located in a lawless swath of Congo adjacent to neighboring Rwanda and Uganda that the government has struggled to control for years.
Kumpel said the one other photograph of an okapi in the wild that scientists previously knew about showed only a leg.
The okapi is threatened by poachers who kill it to sell "bush meat," Kumpel say. The okapi could become extinct in the park soon because of poaching and the effects of the fighting between rebels and government forces on conservation efforts, she added.
Earlier this year, the Zoological Society photographed another shy mammal, a pygmy hippopotamus, in Liberia. That animal had not previously been photographed there, scientists said.
