LEOTHREAT carried out fieldwork in Uganda and Tanzania. In Uganda, samples were collected from 8 lions in Queen Elizabeth National Park, together with prey and environmental samples along a potential exposure gradient from the Kilembe mining area. The Ugandan samples have not yet reached NTNU because of unresolved export and shipment issues, so their analytical work remains pending.
In Tanzania, samples were collected from 29 lions in Serengeti National Park, together with prey, soil, vegetation and water samples. The field strategy had to be adapted to the real distribution of lions during the expedition, which was strongly influenced by seasonal prey movements. Most samples were therefore obtained in the southeastern part of Serengeti, where lion availability was higher during the field campaign.
The main analytical work was completed for the Tanzanian dataset. Metals were analyzed in lion whole blood, lion hair, lion feces, prey hair and muscle, soil, vegetation and water. Blood plasma clinical-chemical parameters were also analyzed in lion plasma, and stable isotopes were analyzed in lion hair. These results provide the first core dataset of the project and support the interpretation of metal exposure, physiological status and trophic ecology in Serengeti lions.
The first results indicate generally low metal concentrations in the sampled Serengeti lions and their environment. Blood plasma clinical-chemical parameters were within reported physiological ranges, and metal concentrations were generally lower than those reported for other terrestrial carnivores. Therefore, the Tanzanian dataset is currently interpreted as a low-metal-contamination or reference dataset. This limits the assessment of strong pollution-related effects in Tanzania, but provides valuable baseline information for future comparison with more impacted areas.
The project also advanced the evaluation of lion hair as a non-invasive biomonitoring matrix and generated the basis for future comparison between hair and internal exposure matrices. In addition, PFAS and TOPA analyses were added to the Tanzanian samples, expanding the project beyond metals and opening a new research line on emerging persistent pollutants in East African lions.