To generate precise and reliable data on lion populations in Uganda’s Nile Delta, a critical stronghold for African lions within Murchison Falls National Park, wildlife rangers from the Uganda Wildlife Authority (UWA), the country’s leading conservation agency, have showcased their ability.
On 15th October 2024, the findings of the study titled: “Rangers on the Frontline of Wildlife Monitoring: A Case Study on African Lions in Uganda’s Nile Delta,” were published in the journal Nature Communications Biology.
The study carried out between April 6, and June 19, 2022, demonstrates that rangers trained in search-encounter surveys—the scientific gold standard for lion monitoring—can provide robust and cost-effective data on lion populations, which are among the most charismatic yet imperiled species on the African continent.
The study shows that wildlife rangers, a critical component of global conservation efforts but often underutilized in scientific research, can play a pivotal role in the conservation science surrounding the world’s most attractive big cat.
we could ensure a future for Uganda’s lions by empowering rangers and focusing on protecting critical habitats such as the Nile Delta. “This study offers a useful case study for scaling up lion monitoring efforts across Africa, using the invaluable skills of rangers to safeguard these iconic predators.”
Rangers are an underutilized resource.
“Regular population monitoring of imperiled charismatic species such as large carnivores is critical for conservation. Yet, the effectiveness of such monitoring is often compromised due to isolated surveys, limited on-ground capacity, and inappropriate methods.” the researchers noted. They added saying that wildlife monitoring is often resource-intensive, and the utility and cost of different field protocols are rarely reported.
Wildlife rangers are uniquely positioned to contribute to this effort according to the researchers. They live and work in the areas where data is collected and possess intimate knowledge of these landscapes and species. As such, their involvement not only enhances monitoring efforts but also garners governmental support for the outcomes.
The researchers added saying that because rangers frequently have ecological training, they represent a valuable stakeholder group for wildlife monitoring, especially in governments’ long-term conservation programmes.
Their involvement may generate support for the outcomes of monitoring because they work for governments.
The researchers say that because rangers frequently have ecological training, they represent a valuable stakeholder group for participation in wildlife monitoring, especially where governments seek to install long term monitoring programmes.
“Monitoring programmes that are collaborative in nature tend to build capacity, share the resource load amongst conservation stakeholders, increase spatial coverage and are often integrated into local and national conservation plans.” The researchers say.
The study also compares the efficacy and cost-effectiveness of surveys conducted by government tourism rangers against traditional methods using infra-red camera traps. In both instances, the study was motivated by the desire to apply the current state-of-the-art methods for abundance estimation (spatial capture-recapture), which require unambiguous and correctly assigned individual identities.
A previous study designed to collect such data on lions made use of white flash cameras and suggested that infra-red camera traps were likely to be unsuitable for obtaining individual identities.
However, this was not quantified and warrants further investigation since infra-red cameras are often preferable as they are less likely to get stolen due to the fact that they emit much less light compared to white flash cameras. In order to provide recommendations and usable information for future surveys, the researchers quantified the cost of both the camera trap survey, and the one conducted by tourism rangers.
Murchison’s Nile Delta a critical lion stronghold.
The study identified the Nile Delta within Murchison Falls National Park – Uganda’s largest protected area – as a vital area for lion conservation. Despite significant pressures from poaching and oil exploration, making it a critical priority conservation area in the country, the conservation area supports high lion densities. The researchers trained Uganda Wildlife Authority (UWA) rangers in search-encounter techniques, the industry gold standard for monitoring lions for the first protocol.
The second protocol involved deploying 32 paired stations of the state-of-the-art infra-red camera traps. Recording 102 detections (30 individuals) in a 256 sq km area, the search-encounter protocol, two rangers covered 2939km in 76 days.
The lion density in the Murchison Falls Nile Delta was estimated at 13.91 lions per 100 sq km, highlighting this area as a significant stronghold for lion conservation with 102 detections over 76 days. While rangers were often on the front lines of wildlife protection, they were rarely included in scientific research efforts.
The study is one of the first to demonstrate that rangers could effectively lead and contribute to data collection and population monitoring of threatened wildlife according to the researchers. The researchers said that their intimate knowledge of the landscapes and behaviour of target species make them invaluable champions for conservation.
Their results highlight the benefits of collaborating with local stakeholders (rangers) working in tandem with the tourism sector, to execute scientifically sound lion population surveys. The data collected by wildlife tourism rangers generated density estimates with acceptable levels of precision, which could likely be improved by adding more days to the sampling effort.
Cost-effectiveness of rangers.
The cost efficiency of ranger-led surveys was one of the most striking results of the study. For monitoring lions in Africa, the cost of the ranger effort was 50% lower than using remote infrared camera traps, another popular method used for surveying big cats, showing that ranger-led initiatives could be a more sustainable and cost-effective method.
Despite deploying 64 infrared camera traps, the cameras yielded only two usable detections for individual identification, suggesting that camera traps, in their current form, were not yet suitable for lion population monitoring.
Incorporating rangers’ skills in future studies.
“Where wildlife tourism rangers exist, they could be a powerful addition to future lion and wildlife census attempts across the continent.” The researchers argue.
“Their results confirm that the current technology of store-bought infra-red camera traps is not suitable for individual identification of lions, and therefore cannot be applied to analytical models that require unambiguous individual identities” the researchers say.
This may be preferable to white-flash camera traps, which can yield individual identities for lions however they encourage the continued testing and advancement of infra-red camera trap technology.
“Our study also shows the immense importance of the Nile Delta for African lions in Uganda’s Murchison Falls National Park, a protected area with both oil extraction and high rates of anthropogenic snaring pressure.” Says researchers.
In an African context, no species better exemplifies this problem than the African lion (Panthera leo), the paper reads in part. “Lions are a charismatic and imperiled species, which play a significant role in consumptive industries. As such, there is intense interest in their population numbers from a wide variety of stakeholders.”
Historically methods used to monitor lions across Africa have been inconsistent and imprecise. This is because estimating lion numbers across large spatial scales at which they exist is notoriously difficult.
For intensive surveys using rigorous methods within smaller areas, one solution is to regularly deploy multi-agency teams of local stakeholders. Monitoring is not a stand-along activity in this manner but rather a component of conservation decision-making, improving its utility in adaptive management.
To ensure more consistent and reliable wildlife data which is critical for adaptive conservation management, the authors of the research advocate for a broader adoption of incorporating the field skills of wildlife rangers to survey lions across Africa.
“Rangers are the unsung heroes of wildlife conservation. Our co-authors, Lilian Namukose and Silvan Musobozi, have worked for the Uganda Wildlife Authority for over a decade and their deeply intimate knowledge for where lions were in the Murchison landscape allowed us to get a good idea of the status of lions in this critical area. Our study shows bringing rangers into wildlife monitoring and census efforts could be immensely powerful for lions across Africa.” Dr. Alex Braczkowski, the lead author, said.
A Uganda Wildlife Authority ranger and co-author on the study Lilian Namukose added that this was the first scientific study of wildlife where she directly participated and her first entry point into science.
She said that through rigorous training in three workshops across three national parks, they quickly learned to incorporate lion data collection alongside their daily field duties. They are grateful to the Uganda Wildlife Authority for the opportunity to be involved in this work
A Uganda Wildlife Authority ranger and co-author on the study Silvan Musobozi said that rangers are arguably the closest group to wildlife on the ground and have good knowledge of animal behavior. Through capacity building and training, rangers can be better incorporated into the scientific and management process.
“Incorporating Uganda Wildlife Authority Rangers allowed our broader research team to focus on other parts of this very large national park. Their field knowledge of lion behavior meant a high sample size of great data.” the field coordinator of the Volcanoes Safaris Partnership Trust and co-author on the study Orin Cornille said.
Associate Professor at Northern Arizona University and co-author on the study Prof. Duan Biggs concludes that their paper shows that by partnering with in-country conservation agencies and enabling local rangers they can obtain a precise estimate of lion numbers at a fraction of the cost of other techniques.
