During this fellowship, I conducted three field seasons in free living Cape ground squirrels at the unique field site of the Kalahari Research Centre (
http://www.kalahari-meerkats.com/index.php?id=krr(s’ouvre dans une nouvelle fenêtre)) at the Kuruman River Reserve, South Africa, which is maintained and managed by the University Zürich. This project is embedded in a long-term study where up to three volunteers are recording behavioural data, habituating and maintaining groups all year round. Due to my collaborator Prof. Manser, University of Zürich, I have direct access of this unique dataset that will allow investigating group stability by modelling the hierarchy within groups and obtaining information on paternity.
During the first field season I optimized trapping and adapted protocols for blood collection with a team of volunteers and field site manager. Trapping was very successful and almost all present and non-pregnant individuals were caught. While animals were anaesthetised to reduce handling stress, I collected small blood samples, blood smears, and morphological measurements, such as weights, skull, tarsus lengths, etc., which will provide insight into individual body condition. For most individuals I have samples for several field seasons, which will allow me to compare data points between winter/summer and among years. However, the initially planned collection of sperm was omitted due to logistic reasons (i.e. to minimise the length of anaesthesia) and remains a potential project for the future.
The blood samples were shipped to the host’s lab in Glasgow where I conducted DNA extractions, as well as molecular assays to measure markers related to the ageing process including telomere length. The collected blood smears were analysed by a postgraduate volunteer, who counted white blood cells, which provide details on health status of individual animals.
In addition, I performed oxidative stress assays at my collaborator’s lab at the University of Neuchâtel, Switzerland and measured damage to lipids using malondialdehyde in plasma and red blood cells and the ratio of oxidized to reduced glutathione concentrations in the plasma using assays on the high-performance liquid chromatography. Further, a subset of the samples collected have been sent to my collaborator at the University of Pretoria in order to measure testosterone in plasma.
Analyses of these physiological and molecular data are still on-going. However preliminary results suggest that telomere shortening is affected by age i.e. subadults have longer telomeres compared to older individuals, which is in line with the expectations based on other species. Adding information on individual behaviour, group sizes and composition, hierarchy, and the associated physiological changes, will complete the picture about the costs of sociality.
The preliminary results of this project have been presented at several meetings including one symposium on the diversity of telomere dynamics organized in Edinburgh in 2017 to a broad audience (from ecologists to epidemiologists) interested in telomeres and ageing. In addition, I will present my research at the Conference on Behavioural Biology in Liverpool in 2018, all of which enables me to reach a broad audience and will open new perspectives for collaborations.
