It’s often surprising how little we know about the species that humans share our planet with, and the rainforests of Central Africa are a particular biodiversity blank spot. But as the BBC reports, the first large scale camera-trap survey of the Semuliki National Park in Uganda recently cast a little light on the lowland rainforest it encompases. Among the discoveries, the traps snapped the Central East African country’s first recorded sighting of the rare lowland or western bongo, the world’s largest forest antelope.

It’s surprising that the bongo subspecies, which can weight up to 800 pounds, could go so long without a sighting in Uganda. Currently, about 30,000 of the animals, listed as near threatened on the IUCN Red List of endangered species, live in the forests of West and Central Africa. “We were amazed that such a large, striking animal could go undetected for so long, but bongos are a notoriously shy and elusive species,” Stuart Nixon of Chester Zoo’s Africa Field Program, which partnered with Uganda Wildlife Authority on the survey of the 85-square-mile park, tells the BBC.

According a press release, the bongo wasn’t the only animal caught by the traps. In total, the planted cameras took 18,000 snapshots that recorded 32 mammal species, some of which, like the bongo, had never been photographed in the area before. Forest elephants, chimpanzees, buffalo and leopards all set off the traps, as well as more unusual species including elephant shrews, the weasel-like cusimanse and African golden cat.

Guma Nelson, chief warden of nearby Kibale Conservation Area, says in the release that the discovery of these rare creatures shows there are more animals to be found in the park and the other forests of the Albertine Rift, the ancient geologic formation that surrounds it. “The images of the mammal species of other genera captured by cameras attest to this fact,” he says. “With its proximity to the Pleistocene refugia, there are rare and endemic species yet to be discovered if more extensive surveys are done.”

Cataloguing these animals is also necessary for conservation work.

As Nixon of Chester Zoo’s Africa Field Program explains to the BBC, the survey suggests that bongos and other species are moving between Uganda and the bordering Democratic Republic of the Congo's Virunga National Park, demonstrating "just how important it is to protect the rainforests, which still connect the two countries."

Since no lowland bongos are held in zoos, the only way to protect the animal is to combat the illegal hunting, logging, road building and other threats encroaching on the forests they call home.

In recent years, camera traps, relatively cheap motion-activated devices, have become a staple of wildlife research. Two years ago, camera traps helped detect the elusive sand cat in the United Arab Emirates for the first time in a decade and also have proven their worth to researchers tracking snow leopards. In fact, camera traps have become so ubiquitous that researchers are currently looking to find a way to harvest data from trapping projects around the world for use in ecological research.

Editor's note, October 2, 2018: A previous version of this article incorrectly stated in the headline that the lowland bongo is the world's largest antelope, when, in fact it is the world's largest forest antelope. The story's headline has been edited to correct that fact.