Images from camera traps: From the left: female leopard, hyena, male leopard Credit: Rasmus W Havmøller
Spotted hyenas (Crocuta crocuta), one of Africa’s most successful hunters, are outcompeting leopards in a Tanzanian protected area with human help, a study by Danish researchers has found.
This could have serious ‘cascade effects’ in the long run, according to the researchers.
The scientists from the University of Copenhagen studied the inter-specific dynamics between hyenas and leopards using camera traps in Tanzania’s Udzungwa Mountains.
This is an approximately 2,000-square kilometre national park completely surrounded by agricultural and populated areas.
“The study is the first to combine camera observations of large predators over both time and space in a single analysis,” a statement by the university on July 2 noted.
Leopards outsmarted
Leopard populations have been declining worldwide, even as hyena populations have been increasing.
The researchers noted that the species’ social structure, size and sex, as well as their dynamic with humans, all had a role to play in this.
Leopards are solitary animals, except during mating season. Spotted hyenas, on the other hand, live in groups known as ‘clans’ or ‘cackles.’ They are also ‘kleptoparasitic’, in that they steal kills from other predators, including leopards.
“Female leopards (approx. 20-43 kg.) are about half the size of male leopards (approx. 51-72 kg). Hyenas are in the middle in terms of weight (approx. 48-56 kg),” the statement noted.
Leopards are unpopular among locals near the park as they hunt livestock and attack humans. Hyenas, on the other hand, are tolerated as they scavenge on dead or sick livestock and do not usually attack people.
While male leopards can fend off hyenas, they give way to their rivals in human-dominated areas, which usually have the richest pickings.
Female leopards, on the other hand, completely change their behaviour. They become diurnal as hyenas are nocturnal.
“As the local people definitely don’t like leopards, the leopards retreat as far away from humans as possible. Hyenas, on the other hand, benefit from the fact that humans don’t feel threatened by or pursue them. Consequently, hyenas live in close to human populations and may even exploit humans as shields against the leopards,” the statement quoted Rasmus Havmøller from the Natural History Museum of Denmark, University of Copenhagen.
“This suggests that the hyena’s ability to adapt to areas of human activity may strengthen their overall success as a species and their competitive advantage over other large predators as we humans disturb more and more nature,” said Havmøller.
He added that this could have serious consequences as populations of monkey species, kept in check by leopards, would spike and change the balance of the entire ecosystem.
Sex and size matter: Intricate dominance relationships in an East African large carnivore guild has been published in the scientific journal Ecosphere.
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