Large numbers of hyenas and humans coexist, study finds
Large hyena populations are living alongside human communities in Africa without coming into conflict, a recent study has found.
An international team of scientists surveyed the population size and diet of spotted hyenas in northern Ethiopia.
The study found a large hyena population with a diet that consisted almost exclusively of domestic animals.
Humans and hyenas are able to coexist because the cost of livestock predation to the local people is relatively low.
The results are published in the journal of Mammalian Biology.
Laughs and giggles
Spotted hyenas (Crocuta crocuta) are common large carnivores of sub-Saharan Africa, and are the most important large scavengers and hunters in many areas of Ethiopia.
According to lead author Gidey Yirga of Mekelle University, Ethiopia, these findings demonstrate a "remarkable case of co-existence between spotted hyena and local communities".
The study, conducted in the Wukro district of northern Ethiopia, determined that this area has very little natural prey because agriculture has degraded and fragmented the habitat.
The consequence is that "spotted hyenas are almost entirely dependent on anthropogenic food," Mr Yirga told BBC Nature.
"Based on regular sightings of hyenas we hypothesised that our study area will have moderately high densities, in spite of the absence of native prey," he said.
To estimate the hyena population the team played continuous gnu-hyena distress sounds, as well as spotted hyena sounds, through a megaphone at randomly selected calling stations.
End Quote Gidey Yirga Mekelle University, Ethiopia
Spotted hyenas benefit from waste disposal and human communities benefit from the waste-clearing service”
They found 52 hyenas per 100 square kilometres living alongside 98 people per square kilometre.
By analysing hairs in the hyenas' droppings they found that 99% of their diet was made up of domestic animals - chiefly cattle, donkeys, goats and sheep.
Mr Yirga explained that it is likely that waste scavenging is one of the most important food sources for spotted hyenas and that the associated cost to people is both marginal and tolerable.
This peaceful coexistence is mutually beneficial - "spotted hyenas benefit from waste disposal and human communities benefit from the waste-clearing service," Mr Yirga explained.
He also commented on the wider significance of these findings: "This also indicated that large carnivores could coexist with people at remarkably low costs."