An autonomous recording Unit (left) and camera trap station.CREDIT: Jonathan Growcott
Researchers have found a way to identify individual leopards by analysing the unique temporal patterns in their roars. A team from Tanzania and the United Kingdom conducted the first large-scale study of leopards using bioacoustics—a technique commonly used to monitor birds and marine life. Their analysis, published in Remote Sensing in Ecology and Conservation1 distinguished individual animals at 93% accuracy.
“Leopards are solitary, nocturnal creatures that live across huge expanses of terrain, and scientists struggle to gather reliable data that would help them reverse population declines,” says Jonathan Growcott, the study’s lead author from the Centre for Ecology and Conservation, University of Exeter, in the United Kingdom. “There is little research about the ‘sawing roar’ of a leopard — a repeated low-frequency pattern of strokes, often audible from at least a kilometre away, used primarily to attract mates, and for territorial defense.”
With other species such as lions, wild dogs, and spotted hyenas all having unique vocalisations, the researchers hypothesized that the same could apply to leopards. They studied leopards’ voices across a 450 km2 expanse of the Nyerere National Park in Tanzania, by attaching 50 pairs of cameras to trees along roads and trails. They placed microphones next to each camera so that they could identify the leopard from the vision and extract the roaring bouts from the audio.
Growcott says that a combination of microphones with large detection ranges and improving AI tools that allows researchers to analyse audio data quickly and accurately will enable the inclusion of species such as large carnivores that have not historically been bioacoustically studied.
Leopards are listed as vulnerable to extinction according to the IUCN Red List of Threatened Species. The approach could help conservationists track leopards over much larger areas.
