Human presence is shifting the balance between leopards and hyenas in East Africa

Who is stronger? A lonely leopard or cackling hyenas? And which one is the best at getting along with people?

Scientists from the University of Copenhagen studied this in detail in a large natural area in East Africa surrounded by rural settlements. A study published in Ecosphereshows that the presence of humans has a direct impact on the competitive relationship between two large predator species: leopards (Panthera pardus) – the iconic spotted cat, and spotted hyena (Crocuta crocuta) – a kleptoparasitic and pack hunter, known for its comical appearance and characteristic “laugh”.

“We humans continue to make our way through the little bit of wilderness that is left in the world. Just as we affect wildlife. This study shows that human disturbance disrupts the balance between competing species and that hyenas benefit from this,” says Rasmus W. Havmøller . , first author of the study and a postdoctoral fellow at the Natural History Museum of the University of Denmark in Copenhagen.

Havmøller has been using camera traps for months to observe the dynamics between hyenas and leopards living in Tanzania’s Udzungwa Mountains – some 2,000 km² a national park that is completely surrounded by agricultural and populated areas. The study is the first to combine camera observations of large predators across time and space in a single analysis.

While hyenas as a species appear to be on the rise, leopard populations have been in significant decline for decades, both in Africa and globally. Since hyenas are the only competitor of leopards in this particular natural area, the ability of the two species to coexist is important for their survival. And here the local population is an important factor.

“Since local people definitely don’t like leopards, leopards move as far away from people as possible. Hyenas, on the other hand, benefit from the fact that people don’t feel threatened and don’t chase them. They live close to human populations and can even use people as shields against leopards,” says Havmøller .

“But the areas closest to humans are also the areas with the most prey. And as hyenas assert dominance over these areas, it increases their ability to defeat leopards and potentially threaten the leopard’s adaptability,” adds Havmøller.

Size matters

Scientists’ observations confirm that size matters. While male leopards, who are larger, maintain dominance over hyenas, the situation is different for female leopards, who are smaller.

“Although the male leopards are in charge, the hyenas are not exactly afraid of them. They just hang around in the background – probably to follow the leopards and steal their prey. But the physical inferiority of the hyenas seems to be compensated in the areas closest to humans, because the males leopards are pulled out,” says Havmøller.

“Leopard females, on the other hand, completely change their behavior when hyenas are in the area. They become diurnal, while hyenas are primarily nocturnal. This is probably because female leopards are smaller than hyenas and they are likely to lose any fight.” over prey.”

Overall, the study shows that hyenas benefit from living near humans.

“This suggests that hyenas’ ability to adapt to areas of human activity may enhance their overall success as a species and their competitive advantage over other large predators as we humans disturb more and more of nature,” says Havmøller.

When leopards are under pressure, cascading effects can follow

According to the researcher, the shift in leopard hunting patterns may have negative consequences. “If you open up to more tourism and build more roads in the national park, there will be immediate pressure on female leopards. They can’t tell the difference between safari tourists who are most active during the day and poachers.”

“Over time, they will probably learn that the safari guests are not dangerous. But if there is a large and rapid influx of people into the area, you will probably see a decline in their population,” says Havmøller.

If leopards are seriously pushed out of the food chain, so-called cascade effects can be expected to occur in the ecosystem. “Putting a large predator like leopards out of the food chain, which may be the ultimate result of human disturbance, can have very violent effects.

“Populations of other species, such as certain monkeys whose populations are held in check by leopards, suddenly become too numerous and change the balance of the entire ecosystem,” says the researcher.

As such, Havmøller hopes the study will serve to encourage restraint when it comes to managing wilderness areas.

“Our results clearly indicate that human disturbance can change the competitive relationship between important predators. So I hope that considerations will be taken into account when expanding activities in wilderness areas to develop them slowly and give the animals a chance to adapt.

“In addition, it would be good if the effects of human disturbance were monitored using camera traps in more places,” concludes Havmøller.

hyenas vs. leopards

• Leopards are unpopular with local people in many places because they can hunt livestock and attack people. Hyenas, on the other hand, “clean up” by eating sick or dead farm animals and are not a problem for humans.
• Female leopards (approx. 20 kg–43 kg) are roughly half the size of male leopards (approx. 51 kg–72 kg). Hyenas are in the middle in terms of weight (approx. 48 kg–56 kg).
• Leopards are solitary hunters, while hyenas hunt in large packs (clans), which can be an advantage for hyenas in confrontations with leopards.
• Hyenas are kleptoparasites that regularly steal prey from other carnivores – including leopards.
• On the other hand, leopards are master tree climbers, which allows them to protect their prey from hyenas.