Proceedings of the Vertebrate Pest Conference

California ground squirrels have been implicated in causing damage to anthropogenic structures, critical infrastructure, sensitive wildlife species, and agricultural areas in California. Current methods employed to reduce the abundance of California ground squirrels include trapping, shooting, exclusion, fumigation, filling of burrows, natural predation, habitat modification, and use of rodenticides. Recent technological advances in rodent traps provide an opportunity to test CO2-powered, self-resetting traps to reduce California ground squirrel abundance. Goodnature A24 automatic rat+stoat traps deployed in three 80 × 80 m trapping arrays reduced the relative abundance of California ground squirrels on average by 84.8% over a period of nine days. When trapping arrays were compared to control arrays, A24 automatic traps also significantly reduced the relative abundance of California ground squirrels. Inspection of California ground squirrel carcasses indicated that A24 automatic traps successfully controlled adult male and adult and juvenile female California ground squirrels. Although these data are preliminary, A24 self-resetting traps show promise as an effective and efficient means to reduce California ground squirrel abundance, potentially reducing the need to implement less efficient methods and methods that pose a risk to non-target wildlife in higher trophic levels, including rodenticides. Logistical issues, non-target wildlife effects, human safety concerns, and future directions of this research are also discussed.