Carnivore conservation has become a global challenge, as populations of many large carnivore species are declining worldwide and becoming increasingly restricted to protected areas. Collecting baseline information on carnivore populations, such as abundance and distribution, is crucial to making informed conservation and management decisions, as well as guiding wildlife experiences for tourists. However, population estimates for more elusive species and those occurring at low densities can be difficult to obtain, and data are often lacking, even for the most renowned protected areas, such as Etosha National Park.
Similar to numerous other places in the world, large carnivores are keystone species in the Greater Etosha Landscape and a major tourist attraction within the Park and surrounding properties. While lion population surveys have been conducted in the past, very little is known about other large predator species such as spotted hyenas, leopards, and cheetahs. Further, there has been no comprehensive survey that has included both the Park and game reserves that border the park, which are also home to numerous carnivore species. This represents a major knowledge gap and in the absence of updated population estimates, conservation and management initiatives are severely handicapped, risking undetected population declines.
Counting carnivores is no simple task though. The most reliable methods for estimating population sizes often depend on identifying individuals – typically by their unique coat patterns. While this works well for species like cheetahs and leopards (see our previous blog entry), it’s far more challenging for lions and spotted hyenas. Luckily, these two species are social animals that rely on long-distance communication, which allows us to “trick” them into responding to playing back recordings of their own calls or those of prey species in distress. Although this method is less precise than identifying individuals, it enables us to cover larger areas and survey multiple species more efficiently.
Building on previous lion playback surveys conducted in Etosha National Park, we extended the approach to include neighbouring reserves. This survey also targeted additional species, such as spotted hyenas and black-backed jackals.
In September 2024, around full moon, our nights were spent driving through Etosha and the surrounding properties. Equipped with a loudspeaker mounted on the vehicle’s roof, we played recordings of distressed springbok, barking black-backed jackals, and whooping, quarrelling hyenas at a carcass. This effort was realised through collaboration. Our partners within the Greater Etosha Carnivore Programme (Ministry of Environment of Forestry and Tourism, Etosha Ecological Institute, University of Georgia, Leibniz Institue for Zoo and Wildlife and University of Ljubljana) contributed extra hands, equipment, vehicles, and other essentials. Our colleagues from the Giraffe Conservation Foundation, Onguma Game Reserve and the Lion Rangers also joined this effort and conducted the survey on Etosha Heights Private Reserve, Onguma Game Reserve and the Hobatere Concession. Additionally, the financial support from Wilderness and the Namibian Chamber of Environment was instrumental in bringing this survey to life.
So, how exactly does a playback survey work? The first step is to select the locations for playback stations. Most of our stations were near waterholes, as these are critical hubs in our arid ecosystem. However, we also incorporated GPS data from collared lions and hyenas to ensure no carnivore groups were missed. The surveys began about 30 minutes after sunset, continuing through the night and sometimes until dawn. Each night, we tried our luck at three to six stations.
At each station, we mounted the speaker to the vehicle’s roof and played a sequence of recordings for one hour, with pauses in between. Lions and hyenas, which can hear the playback within roughly a 3-km radius, often responded by approaching the vehicle. In contrast, jackals typically barked in reply. Interestingly, jackal responses can also help estimate whether they belong to the same family group, as group members often respond together, while calls from different groups rarely overlap.
We carefully recorded every response, noting the species, group composition, and time of arrival. Then we moved to the next station and repeated the process. However, not all carnivores that hear the recordings will actually respond. For instance, individuals feeding or caring for young are less likely to approach. This means the carnivores observed during playback surveys, likely represent an underestimation of the actual population.
Over six nights, seven teams and vehicles surveyed a total of 122 stations—92 within the Park and 30 on surrounding reserves. In the end, we recorded 87 lions, 183 spotted hyenas, and 252 black-backed jackals. Particularly interesting were the observations of nine brown hyenas, two leopards and five cheetahs.
Some of the teams had the luxury of using thermal vision instruments, which proved to be a game-changer. These tools allowed us to detect approaching animals much earlier and with greater accuracy, especially in areas where dense vegetation surrounded the vehicle. Beyond their scientific value, the thermal vision devices added an element of excitement to our nights, capturing fascinating and often entertaining footage of the wildlife in action.
The results of this survey will offer updated population size estimates for lions, spotted hyenas, and jackals, providing crucial data to guide conservation and management decisions in this vast and intricate landscape. Watch this space for Part II, where we’ll unpack some of the exciting findings from this survey.
