Tanzania’s lions need protecting in one of the species’ last remaining strongholds
June 24, 2025The Selous-Nyerere ecosystem in southern Tanzania is one of Africa’s largest wilderness areas. Although considered one of the last remaining strongholds for lions, this population had not been studied for more than a decade until recent efforts by WildCRU researchers to shed light on the current status of the population.
This assessment, which looked not just at lions but also at leopards, spotted hyaena, and African wild dogs, presented a considerable challenge: the entire ecosystem spans more than 80,000 km2, with Selous Game Reserve and Nyerere National Park together covering nearly 50,000 km2 – an area larger than Switzerland. In addition to having to cover an enormous area, the researchers also had to contend with the challenge of collecting data on large carnivores, whose naturally low densities and secretive behaviour make population monitoring particularly difficult.
Over three dry seasons (2020-2022), the researchers set 638 remotely triggered camera traps along roads and trails at seven sites, each spanning 500–2500 km2. After they individually identified all lions in the photos, the researchers estimated population density based on where and when each lion was captured using a method called spatially explicit capture-recapture (SECR) modelling. Density appeared to mostly be driven by the availability of prey, which is itself primarily driven by the food available in miombo woodlands – an understudied but important habitat for lions, making up nearly a quarter of the species’ present range (24%).
However, the study revealed human impacts in areas close to boundaries, including bushmeat snaring and intentional poisoning. This may explain why the lowest population density was found in the survey site closest to unprotected village lands – which had the second highest number of recorded illegal incursions and animals with visible snare injuries – despite this site also having the second highest abundance of preferred prey.
Image: Charlotte Searle
The researchers are now putting their findings into action with a long-term carnivore monitoring and conservation programme in Selous-Nyerere, which includes:
- Regular population monitoring for lions and other large carnivores to monitor population trends, via repeat camera trap surveys.
- More in-depth monitoring of lion prides and wild dog packs, achieved by deploying GPS collars on lions and wild dogs to understand how they are moving and dispersing through high-risk areas and inform de-snaring patrols and other protection activities.
- Continuing efforts to reduce human-lion conflict in neighbouring village lands.
Lead researcher Dr Charlotte Searle said:
“After three years of incredibly hard work by an international team of collaborators*, our surveys have helped us understand how lions are currently faring in the Selous-Nyerere landscape and, even more importantly, identify what actions should be taken to safeguard this lion stronghold into the future. This programme has the potential to bring benefits for both biodiversity and poverty reduction, thanks to these species’ role in shaping wider wildlife communities and generating income and employment through tourism.”
The WildCRU team worked closely with colleagues from the local protected area management authorities TAWA & TANAPA and the Tanzania Wildlife Research Institute (TAWIRI). This highly-collaborative approach not only equipped local participants with the skills and knowledge to monitor large carnivores, but also ensured local perspectives and knowledge fed into the work, resulting in much more impactful – and actionable – conclusions and recommendations. Now, participants in the assessment are using their new skills to carry out their own research: Singira Parsais, the Head Ecologist of Selous with TAWA, is studying the status of and threats to Selous-Nyerere’s wild dogs, while TAWIRI’s Leonard Haule is researching lion and wild dog distributions and genetics. These efforts represent the first ever Tanzanian-led research on these globally important carnivore populations.
Image: Charlotte Searle
*This study was carried out by researchers from Oxford Biology’s Wildlife Conservation Research Unit (WildCRU) and the NGO Lion Landscapes, in close collaboration with protected area management authorities TAWA & TANAPA and TAWIRI.
The work was also supported by Frankfurt Zoological Society, and was funded by the Wildlife Conservation Network’s Lion Recovery Fund, the UK Government through the Darwin Initiative Capability & Capacity fund, WWF Germany, and the National Geographic Society Big Cats Initiative.
To read more about this research, published in Journal of Zoology, visit: https://doi.org/10.1111/jzo.70019