Lions are famously dubbed the "kings of the jungle," but they aren't the predators African wildlife fears most. According to a study published by ScienceAlert, mammals across the African savannah are significantly more terrified of humans than lions, highlighting the profound, disruptive footprint people leave on wild ecosystems.
To measure how wildlife perceives different threats, researchers conducted a series of experiments at waterholes in South Africa's Greater Kruger National Park, which hosts the world's largest remaining lion population. The team broadcasted various audio recordings, ranging from ordinary human conversations and hunting cues (like gunshots and barking dogs) to lion growls and snarls and used motion-triggered cameras to capture the animals' reactions.
According to the ScienceAlert report, the findings were striking. Nearly all of the 19 mammal species studied, including elephants, rhinos, giraffes, zebras, leopards, hyenas and warthogs, were about twice as likely to flee after hearing human voices as they were after hearing lion growls or hunting-related sounds. The researchers said the results suggest that wildlife perceives humans as the greatest threat.
Conservation biologist Michael Clinchy of Western University said the fear of humans is "ingrained and pervasive". He added that even animals living in protected areas where hunting does not take place do not become accustomed to the presence of people.
The researchers said similar patterns have also been observed in Australia, where kangaroos and other marsupials reacted more strongly to human voices than to the sounds of their natural predators. They believe the findings suggest wildlife across different continents recognises humans as the planet's true "super predator".
The discovery could also have practical benefits for conservation. Scientists are exploring whether recordings of human voices could be used to keep endangered animals, including southern white rhinos, away from areas where poachers are active. However, they also warned that constant fear of humans can alter animal behaviour and, over time, contribute to declining populations.
The study was published in Current Biology, with the findings further supported by later research published in Proceedings of the Royal Society B.
