Bimodal nocturnal activity and age-specific burrow entrance use in a social fossorial rodent: implications for conservation

Understanding the behavioural patterns of fossorial and colonial rodents is crucial for effective conservation and management strategies, particularly in the face of population declines and local extinctions. Translocation projects are increasingly used to restore populations in protected areas and promote ecological restorations, yet limited knowledge of species-specific behaviours may compromise their success. In this study, we focused on the plains vizcacha ( Lagostomus maximus ), a highly social and fossorial rodent native to South America, currently facing such conservation challenges. We characterized its behavioural repertoire, and examined activity patterns and burrow entrance use, considering time of day, age differences, and burrow characteristics. We found a previously undocumented bimodal nocturnal activity pattern, with peaks between 22:30–00:00 and 3:00–6:00, which may be linked to thermoregulation and predator avoidance. The different age classes exhibited distinct behaviours at burrow entrances. While adults used all available entrances, juveniles and young individuals preferred those without tree cover, likely reducing aerial predation risk while facilitating access to foraging resources. These findings provide key insights for conservation efforts, emphasizing the need to optimize capture times and design artificial burrow systems that account for age-specific spatial use and predator avoidance strategies in translocation programs.