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Who is stronger? A lone leopard or giggling hyenas? And what is the best way to get along with people?

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

“We humans continue to make our way in the little wilderness left in the world. As we do so, we impact wildlife. This study shows that human disturbance disrupts the balance between competing species and that this benefits hyenas,” says Rasmus U. Havmöller, first author of the study and a postdoctoral fellow at the Danish Museum of Natural History, University of Copenhagen.

For months, Havmøller used camera traps to observe the dynamics between hyenas and leopards living in the Udzungwa Mountains of Tanzania – approximately 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 carnivores across time and space in a single analysis.

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

“Because the local people definitely don’t like leopards, they retreat as far away from people as possible. Hyenas, on the other hand, benefit from the fact that humans do not feel threatened by them and do not chase them. Therefore, hyenas live in close to human populations and may even exploit humans as a shield against leopards,” says Hawmöller.

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

Size matters

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

“Even though the male leopards are the ones in charge, the hyenas aren’t exactly scared of them. They just hang around in the background – probably to follow the leopards and steal their prey. But the physical inferiority of hyenas seems to be compensated for in the areas closest to humans, because the male leopards get away,” says Hawmöller.

“Female leopards, on the other hand, completely change their behavior when hyenas are in the area. They become diurnal while hyenas are mostly nocturnal. This is probably due to the fact that female leopards are smaller than hyenas and that they are likely to lose in any battle over prey.”

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

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

When leopards are under pressure, cascading effects can follow

According to the researcher, the change in hunting patterns of the female leopard could have negative consequences. “If you open up to more tourism and build more roads in the national park, the female leopards will immediately be squeezed. They are unable to differentiate between safari tourists, who are most active during the day, and poachers.

“Over time, they will probably learn that safari guests are not dangerous.” But if there’s a large and rapid influx into the area, you’re likely to see a decline in their population,” Hawmöller says.

If leopards are seriously pushed out of the food chain, what are known as cascading effects in the ecosystem should be expected. “Putting a large predator like leopards out of the food chain, which can be the ultimate consequence of human disturbance, can have very cruel consequences.

“Populations of other species, such as some monkeys whose populations are controlled by leopards, will suddenly become too large 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 show that human disturbance can alter competitive relationships between important predators. So I hope they will be taken into account when expanding activities in wildlife areas so that they roll out slowly and give the animals a chance to adapt.

“Also, it would be good to monitor the effects of human disturbance in more places using camera traps,” Hawmöller concludes.

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, “scavenge” by eating sick or dead livestock and pose no problem to humans.
• Female leopards (approximately 20 kg–43 kg) are about half the size of male leopards (approximately 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 encounters with leopards.
• Hyenas are kleptoparasites that regularly steal the prey of other carnivores, including leopards.
• Leopards on the other hand are master tree climbers which allows them to protect their prey from hyenas.