In the Savanna, human voices scare mammals more than lions’ roar

For generations, lions have been revered as the ultimate apex predators, often referred to as the “kings of beasts.” Now, a groundbreaking study led by Western University biologist, Professor Liana Zanette, in collaboration with renowned lion expert, Craig Packer from the University of Minnesota, has unveiled a profound shift in the understanding of fear dynamics within the African savanna.
Their pioneering research lays bare a startling revelation: the reign of fear held by humans, dubbed the “super predator,” transcends that of lions and casts a shadow of apprehension across nearly all mammal species inhabiting the expanse of South Africa’s Greater Kruger National Park.
Zanette and her team conducted experiments that provided compelling evidence of the pervasive fear of humans among wildlife. They deployed hidden automated camera-speaker systems at waterholes, triggering animal responses when creatures approached within approximately 10 metres or 30 feet. The sounds included humans speaking calmly in locally-used languages, lions snarling and growling, hunting sounds, and non-threatening controls like bird calls.

The results were staggering. “Wildlife in the area were twice as likely to flee and abandon waterholes 40% faster upon hearing human voices compared to lions or other hunting sounds. Remarkably, almost 95% of species surveyed reacted more strongly to human sounds than those of lions,” according to the study published in the journal Current Biology on Thursday.
The finding was true for giraffes, leopards, hyenas, zebras, kudu, warthogs, and impalas, all of which exhibited heightened fear responses to human voices. Elephants and rhinos were also observed to abandon waterholes significantly faster upon hearing humans than lions.
“These findings add a new dimension to our worldwide environmental impacts,” said Zanette, adding, “The very substantial fear of humans demonstrated here, and in comparable recent experiments, can be expected to have dramatic ecological consequences, because other new research has established that fear itself can reduce wildlife numbers.”
Global surveys show humans kill prey at much higher rates than other predators, making humans a “super predator.” “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 that each system’s non-human apex predator, like lions, leopards, wolves, cougars, bears and dogs,” said Zanette.
Researchers emphasise that the substantial fear of humans demonstrated can have dramatic ecological consequences. Recent research has shown that fear itself can reduce wildlife populations.
As a result, protected areas management and wildlife conservation face a significant new challenge. It is clear that even benign humans, such as wildlife tourists, can induce previously unrecognised impacts due to the fear they instil in wildlife. Conservation efforts must now consider not only the direct threats posed by humans but also the indirect consequences of the fear they evoke in the animal kingdom.
With this newfound understanding, wildlife conservationists face a pressing challenge to protect and preserve the natural world in the face of the pervasive fear of the human “super predator.”