The King of the Jungle may be scary, but when it comes to instilling fear he has nothing on that global super predator – the human being.

Humans are so feared that even their voices can make the biggest animals turn and flee, and proof of this comes from a recent study conducted in the Greater Kruger National Park.

Researchers were able to show this after setting up hidden camera-speaker systems at a number of waterholes and collecting thousands of videos.

When triggered by a passing animal, the system would either broadcast audio of humans talking, lions growling or snarling, dogs barking, gunshots or the more neutral sound of birds calling. Video recorded how the animal responded.

The human soundtracks were of people in casual conversation, talking about growing up, or about speaking Afrikaans. But that sound was enough to scatter a herd of giraffes, and get a leopard to drop the impala it was carrying and bolt for cover. 

“On average, things were twice as likely to flee upon hearing humans speaking as they were from hearing lions. We could also measure how long it took them to abandon the waterhole. They were 40%, faster when they heard humans, to when they heard lions,” explains Dr Michael Clinchy, of the University of Western Ontario and a co-author of the paper that appeared in the latest issue of Current Biology.

Both big and small animals were found to be more afraid of human chatter than the snarls of a lion.    

“Everything from a Steenbuck to an elephant is more afraid of us than a lion,” says Clinchy.

Deer flee at the sound of a wolf howl, even though they might live in areas where these apex predators have been extinct for hundreds of years.

They found that of the animals that triggered the camera-audio trap, 95% of them fled when they heard a human.

And South African wildlife is not unique.

“Consistent with humanity’s unique lethality, data from North America, Europe, Asia and Australia and now our work in Africa is demonstrating that wildlife worldwide fear the human super predator far more than each system’s non-human apex predator like lions, leopards, wolves, cougars, bears and dogs,” said the lead author on the paper University of Western Ontario biology Professor Liana Zanette.

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For those animals forced to live in close proximity to predators it is a life consumed by stress that can even threaten their species’ survival.

Lead author Liana Zanette sets up the camera trap and speaker system in the Greater Kruger National Park. (Photo: Supplied)

Studies have shown that this fear of predators can have an effect on reproduction. In one study predator calls were played near nesting songbirds. They were found to forage less and raised half as many chicks.

Interestingly some animals even have fear of predators they have never encountered.

Elephants might remember culling events from decades ago or have been the victim of poaching incidents.

Deer flee at the sound of a wolf howl, even though they might live in areas where these apex predators have been extinct for hundreds of years.

Perhaps this might have to do with inherited memory, passed down from ancestors who did see and were eaten by wolves.

Generational memories might also explain how animals in Kruger are scared of humans. Some animals like elephants, explains Clinchy, could have memories of traumatic experiences involving humans. Elephants might remember culling events from decades ago or have been the victim of poaching incidents.

Other species might just know that it is best for them if they stay away from a predator that has a rap sheet of killing that goes back tens of thousands of years.

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The researchers are now looking at how animals react to humans in vehicles, a common combination in the Kruger National Park.

The soundtracks on the camera traps include humans speaking in cars and the scientists will soon be sifting through thousands of videos to see how the animals react.

Possible uses

But there might be an advantage to this universal fear of humans, that can be used in nature conservation.

Human voices could be used as audible scarecrows to keep some animals from venturing into areas of danger, or chase predators away.

In Florida, in the US, there are plans to protect shorebirds from raiding coyotes and raccoons, by using human soundtracks.

Human audio could in the future chase off rhino and prevent them from entering poaching hotspots.  

“What you need to remember is that humans are the best wildlife deterrents,” explains Clinchy. DM

This story first appeared in our weekly Daily Maverick 168 newspaper, which is available countrywide for R29.