Abstract: Invasions and anthropogenic disturbances challenge species with rapid environmental changes. Understanding how organisms respond to these changes is of major concern for the future of biodiversity. The house mouse on a Sub-Antarctic island (Guillou Island, Kerguelen Archipelago) had to face such challenges twice: first when invading the island two centuries ago; and nowadays when coping with an in-depth remodeling of its habitat due to a cohort of anthropogenic changes. Morphometric and biomechanical results show that the initial invasion triggered the evolution of a jaw shape adapted to the local food resources. Contemporary changes are also associated to changes in jaw morphology, but are not directly functionally relevant. Here, a complex response integrating feeding behaviour, investment in feeding structure, and degree of mineralization, may provide the mice with a better tool to benefit of wider resources utilization and/or better cope with intra-specific competition in a changing habitat. These Sub-Antarctic mice exemplify that success of invasive species rely on the capacity of facing rapidly varying environments through integrated, multi-faceted responses involving behaviour to morphology through life-history traits.