Introduction

• Urban rodent management faces challenges such as overreliance on rodenticides and resistance to alternative methods.

• The goal is efficient population control while reducing environmental and health risks.

• Integrated Pest Management (IPM) is advocated, though it often lacks validated methods for urban environments.

Methods

• Site Selection: Four treatment types—Bait, Mixed (bait and traps), Trap, and Control—were tested in commercial, residential, and institutional settings in Orange County, California.

• Monitoring Tools:

  • Tracking tunnels measured rat activity.

  • Rat telemetry tracked individual movements.

  • Bait consumption and mortality rates were assessed.

• Analysis: Occupancy modeling and statistical tools assessed effectiveness.

Results

• Effectiveness of Treatments:

  • Trap Treatment was the most effective, reducing activity significantly compared to baiting or mixed methods.

  • Bait Treatment and Mixed Treatment showed lower mortality and bait consumption issues.

• Mortality & Survival:

  • Mortality was highest in Trap Treatment but delayed in other methods, possibly due to bait neophobia or sublethal doses.

• Rat Activity: Control sites showed the highest activity, indicating the need for intervention.

• Management Time: Trap treatments required significantly more time and labor than bait treatments.

Discussion

• Rodent neophobia, resource abundance, and bait station design hinder effectiveness.

• Tracking tunnels provided valuable data but faced practical challenges like theft and vandalism.

• Sustained lethal management may not significantly reduce populations due to compensatory reproduction and survival mechanisms.

• Current rodenticide applications are hindered by low uptake and delayed effects.

Conclusions

• Trap-based management was effective but labor-intensive and costly.

• There’s a critical need for better tools, strategies, and education on rodent behavior to improve urban rodent management practices.

• Development of BMPs must focus on practical, scalable methods that balance cost, effectiveness, and ecological impact.