Just after sunrise, a cacophony of whoops and chatter can be heard over the verdant forests of the Afi mountain wildlife sanctuary. Nestled within the Cross River rainforest in south-east Nigeria, and spanning an area about the size of central Paris, the steep sanctuary is a haven for endangered gorillas, drill monkeys, the grey-necked rockfowl – and the short-tailed roundleaf bat.

The Nigerian biologist Iroro Tanshi remembers the moment she first spotted the endangered bat in 2016, during a field expedition for her PhD research. “We were trapping near a roost that night, so we caught a lot of bats,” says Tanshi. But, she adds: “This looked very, very different. Big-eared.” She promptly turned to her identification guide, which revealed that the tiny furry creature she was holding between her fingers was Hipposideros curtus, better known as the short-tailed roundleaf bat, last recorded in the wild in the 1970s.

“That was the moment that changed everything. Actually, there was the catching and the moment of realisation, like: ‘Oh my gosh,’” she says of her breakthrough.

Spurred by this discovery, Tanshi and her small crew of local assistants set up harp traps and mist nets, tracking the cave networks within the Afi sanctuary and the nearby Cross River national park. During their gruelling survey, they found 15 more of the bat species.

The short-tailed roundleaf bat weighs about the same as a level teaspoonful of salt. Unlike large fruit bats, it has relatively small eyes and a large intricately folded nose, which helps it to navigate total darkness through echolocation. It is extraordinarily sensitive to noise and bright lights, so Tanshi typically uses red light during her field research.

“You put it on for a short time and turn it off again to kind of see your way or see the bat that’s hanging there,” she says.

For decades, the species was believed to exist only within specific forest caves in Cameroon and Equatorial Guinea. Thanks to human activities such as deforestation and hunting, all previously documented roosts had been erased by the 2010s. Scientists feared that the species had quietly gone extinct – until Tanshi’s all-important discovery. The small colony she rediscovered around the Afi sanctuary is the only confirmed population of the endangered bat still actively roosting.

However, having rediscovered the bat, Tanshi noticed that most of the attention in the sanctuary went to primates and other large animals, which local people treated with respect.

“People were very familiar with the need to protect nature and conserve these animals,” Tanshi says. “You couldn’t kill those animals in the village without getting reported. But everything else was up for grabs. Regardless of the fact that we were in a protected area, bats were still heavily hunted.”

Historically, bats have been burdened by negative stereotypes, commonly linked to witchcraft and bad omens. Their association with health emergencies, including the Ebola outbreak and Covid, has not helped. “Bats can’t catch a break, sadly,” says Tanshi, who describes the cultural perception of bats in Nigeria as a “complex scenario”. Amid the broader cultural aversion, some Nigerian communities treat the bats as food.

In Abia, a remote village 70km (45 miles) from the Afi sanctuary, the straw-coloured fruit bat is regarded as “normal bushmeat for us, like fish and chicken in other places”, says one villager, Judith Ojong, adding that bats for meat are typically sold in fours for 5,000 naira (about £2.70).

In response, Tanshi, along with Benneth Obitte, another bat specialist, set up the Small Mammal Conservation Organisation (Smacon) in 2016 to champion bats, rodents and other little creatures. The next year they launched the Zero Wildfire Campaign, to combat the destructive blazes that pose another threat to bats.

As part of the campaign, Tanshi and the team at Smacon designed colour-coded alert systems to guide farmers on safe bush burning. To supervise farmers during burning and provide a swift response in the event of an outbreak, Tanshi also formed a group called Forest Guardians. The incidence of wildfires within the forest area has plummeted in the past five years, she says.

In April, Tanshi became one of only six women globally to receive a Goldman environmental award, in recognition of her successful wildfire campaign around the Afi mountain wildlife sanctuary. She was also recently named a National Geographic explorer and has won a Whitley award.

A decade after finding the short-tailed roundleaf bat, Tanshi, a postdoctoral fellow at the Washington Research Foundation, remains enraptured by the hidden diversity in Nigeria’s rainforest and is still amazed at her discovery.

“Something that we thought was extinct was in this beautiful place that nobody goes to,” she says.

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