Cape Ground Squirrels 

My research on Cape ground squirrels (Xerus inauris), which was in collaboration with the Waterman lab, investigated how consistent individual behavioural differences shape survival and reproductive outcomes in a communally breeding group-living mammal. Across multiple studies, we showed that personality traits such as docility, boldness, or exploratory tendency had sex‑specific and context‑dependent fitness consequences. In females, behavioural variation predicts survival but not reproductive success, suggesting that personality influences how individuals navigate predation risk and group dynamics. In males, docility enhances reproductive success without affecting survival, indicating that reduced aggression may facilitate mating opportunities in a system where males cannot monopolize females. Conversely, personality traits do not predict the alternative reproductive tactics males employ, highlighting the dominant role of ecological and social constraints over intrinsic behavioural tendencies. Collectively, this work demonstrates that personality–fitness relationships in social mammals are nuanced, flexible, and shaped by the demands of group living.

Furthermore, we also demonstrated that these arid‑zone mammals are undergoing temperature‑associated morphological changes as their environment warms. Specifically, using nearly two decades of field data, findings indicate that rising maximum temperatures ( ca. 2.5 °C over 18 years) are linked to shifts in body size and appendage dimensions with squirrels exhibiting larger extremities and subtle reductions in body size to improve heat dissipation. These findings provide rare contemporary evidence that mammals are “shape‑shifting” in response to climate change, highlighting both the plasticity and potential vulnerability of species living in extreme thermal environments.