Scholar shedding light on how animals perceive threats

It was Badru Mugerwa’s curiosity that drove him to find out who, or what, was killing the cat. The African Golden Cat, to be more specific. But, he wondered, was it actually being killed? Or was ecotourism behind its marked drop in sightings in the Bwindi National Park in southern Uganda?

What he discovered, in association with Western partners, may help conservationists strike a greater balance between wildlife and ecotourism, while also shedding new light into how animals perceive threats from predators and poachers.

“The African Golden Cat is a very cool species we don’t know that much about,” explained Mugerwa, a Queen Elizabeth (QE) II Scholar, hailing from Uganda. “It’s a medium-sized wild cat, about double the size of a domestic cat, and it’s one of Africa’s least known wild cat species, endemic only in the part of Africa where we have forest.”

One such forest is Uganda’s Bwindi Impenetrable National Park, where Mugerwa has been working as part of a large consortium, monitoring biodiversity in tropical ecosystems. Motion-triggered camera traps, placed systematically in a grid, allowed Mugerwa to observe the temporal trends of elusive wildlife, without needing to be there physically.

“My camera trap data was showing the populations of the Golden Cat were going down. I didn’t really know why, but I had some thoughts on what could be driving those trends. I didn’t think it was hunting, because the cat is a carnivore and, in Uganda, people don’t hunt carnivores. I wondered if it could be ecotourists because in Bwindi, where I worked, there are lots of ecotourists. The numbers are huge.”

Frank Neufeld // Western NewsWhile studying at Oxford University, Queen Elizabeth (QE) II Scholar Badru Mugerwa, who hails from Uganda, connected with Western Biology professors Liana Zanette and Michael Clinchy. Through The Africa Institute at Western, Mugerwa and Zanette have been unlocking the secrets of animal fears and instincts within Uganda’s Bwindi Impenetrable National Park.

So are the dollars, with tourists paying approximately USD$750 to see endangered mountain gorillas. Of the 880 mountain gorillas left in the world, half of them live in Bwindi, a premier African-protected area and the main source of Uganda’s ecotourism revenue.

“My reasoning was these cats are likely not declining in populations per se, but it may be just an avoidance of ecotourists.” But he knew his reasoning wasn’t conclusive, being that traditional camera traps only provide correlative data, without experimental controls.

He needed a better method to understand what was behind the cats’ behaviour. And while studying at Oxford University, he found it, through a chance meeting with Western Biology professors Liana Zanette and Michael Clinchy, who were there on sabbatical.

And it was Zanette that drew Mugerwa to The Africa Institute at Western as a master’s candidate in Biology & Collaborative Program in Global Health Systems in Africa. “Liana is the expert; she is the authority in these kinds of questions in the playback experiment world,” he said.

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“Animals don’t lie. They tell us who they’re afraid of.”

Zanette said this with great authority. And, she’s earned it, having studied the many dimensions of predator-induced fear on animals around the world.

Her lab has demonstrated although fear in animals can help restore ecosystems, it is also powerful enough to reduce the birth and survival rates of songbird prey, and can cause cascading effects down through ecosystems and down food webs.

“We know animals know who their enemies are, and they are able to tell us,” she explained. “Even though it’s all people, they can discriminate, and know which ones they should fear.”

CBC’s Nature of Things followed her team to South Africa last July to show how cameras and her ABR system are transforming our understanding of nature, for an episode to air in early 2018.

To unlock these secrets, Zanette and her team have created the Automated Behavioural Response (ABR) system to study and directly test fear responses on badgers in the U.K., pumas in California, black bears on Vancouver Island and many species of wildlife in South Africa. The system integrates playback experiments into camera trap studies.

Her highly cited work has attracted Natural Sciences and Engineering Research Council of Canada (NSERC) funding and international media attention.

“Playback experiments allow us to directly test the behavioural responses of animals,” Zanette explained, “allowing us to make rigorous conclusions.”

Zanette’s ABR system is comprised of a custom-built motion-sensitive speaker system that can be paired with any commercially available camera trap, providing the means to conduct playback experiments directly testing the behavioural responses of any species ‘caught’ on a camera.

“Our innovation is that we use the exact same sorts of cameras, but we use a video component as well, so we can watch the animal’s behavior,” she explained. “Then we hook up our custom-built speaker into the camera so when the animal walks by it will start recording its behaviour, and a sound will play – any sound that we want. We then can gauge the animal’s response to that stimulus.”

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The sounds selected for Mugerwa’s investigation on the Golden Cats included insects, as the control variable, since animals in Bwindi have no reason to fear bugs; humans speaking English, to represent the ecotourists; sounds of dogs, both free-running, and those used in poaching; and leopards, Bwindi wildlife’s most feared native predator, extinct in the park for more than 50 years.

“I wanted to know if we could use an animal’s fear response to cues that represent human activities to understand how human impacts threaten wildlife in national parks,” he said.

Using three data points – when the animal was first seen in the video, when the playback was set off and when the animal was last seen in view – Mugerwa constructed an index that measured the animals’ response to each sound. The animal remaining standing, not scared, was registered at ‘zero.’ The value reduced if the animal walked away, and the value became even more negative if the animal bolted and ran away.

“I had three predictions: The wildlife would respond fearfully to ecotourists as predators; the wildlife would respond fearfully to dogs as predators; and the wildlife in Bwindi will be naive to the sounds of extinct large carnivores, reflecting the loss of the behaviour affected by large carnivores,” he explained.

There were some surprises.

“We did that experiment for 45 days and we had more than 2,000 videos. That was big. We not only got videos for one species, but actually 14, from sizes ranging from an elephant to something as small as a squirrel,” Mugerwa said. “That was huge for us. It was exciting.”

And from a conservation perspective, so were the overall results.

“We saw the animals responded similarly the first time to humans as they did to the insects. But with the dogs and leopards, the animals responded more significantly than they did compared to the insects.

He continued, “Also, after repeated exposures to the sounds, animals at Bwindi continued not to respond to the sounds of insects and not to respond to the sounds of humans. However, they did continue to respond to dogs and leopards, suggesting the animals in Bwindi may not be perceiving ecotourism as a threat, but they do perceive dogs, as a major predator and a threat, and they still recognize cues or sounds of the extinct large carnivore predator.

“These findings have conservation implications,” Mugerwa continued. “One of them being that ecotourism is a good thing, and can be shared with organizations such as the Uganda Wildlife Authority, and other national parks as well.”

That’s good news for Uganda, where most of the population suffers in poverty. With a large portion of their GDP coming from ecotourism, its rise could also increase the amount of foreign revenue available to help fund roads, schools and hospitals.

“Secondly,” Mugerwa continued, “dogs are really bad. They’re not cute, little cuddly dogs like you have here. These dogs are trained to hunt and kill. The parks should find ways of controlling not only the village, free-running dogs, but also, the poaching dogs.

“And lastly, animals still recognize leopards. They have been gone for the past 50 years in national parks, but the animals still recognize them, meaning the leopards could be reintroduced into the parks without causing significant predation on the wildlife. The animals at Bwindi clearly still see leopards as a threat.”

Mugerwa went on to note that leopard re-introduction will only be possible through consultative agreements with all stakeholders, as leopards kill people, livestock and may also kill gorillas.

But what is happening to the African Golden Cat if it’s not afraid of ecotourists?

Mugerwa fears illegal poachers are snaring them, removing them as competitors in their hunt for small antelope.

And, with his studies at Western complete, and heading back to Uganda, it’s on poaching that Mugerwa wishes to focus next.

“I’ve shown the animals have responded to tourists. Now I want to show how they respond to the local people, poachers who don’t speak English, but speak the local languages. With the ABR and this kind of work, we can actually measure the level of poaching, just based on how these animals react to the sound of the local languages. So, if the animals respond fearfully, it will indicate they perceive some level of threat, and that can be used to index the level of illegal hunting or poaching.”

QE II Scholars

In 2015, The Africa Institute at Western was awarded the prestigious scholarship. Since then, Western students have taken part in experiential learning experiences in Kenya, Uganda, Nigeria, Ghana and Tanzania. Conversely, several faculties at Western have also hosted graduate students from Kenya, Ghana, Nigeria, Rwanda, Uganda and Tanzania enrolled through the Collaborative Graduate Program in Global Health Systems. This year, 21 students took part in the program.