Capsicum-laden soils decrease contact time by northern pocket gophers.

Area of Science:

• Wildlife Management
• Pest Control
• Behavioral Ecology

Background:

• Fossorial rodents, such as northern pocket gophers (Thomomys talpoides), cause significant damage to lawns, agricultural crops, and water impoundments.
• Effective and environmentally conscious methods for managing rodent populations are crucial for mitigating these damages.

Purpose of the Study:

• To evaluate the efficacy of capsicum-oleoresin soil mixtures as a deterrent for northern pocket gophers.
• To assess the impact of varying concentrations of capsicum-oleoresin on gopher behaviors, including soil contact, digging, and grooming.

Main Methods:

• A two-choice, parametric study design was employed.
• Northern pocket gophers were exposed to soil mixtures containing 0.00% (placebo), 0.75%, 1.50%, and 2.25% capsicum-oleoresin over three alternate-day sessions.
• Behaviors such as soil contact, soil digging, and pelage grooming were systematically recorded and analyzed.

Main Results:

• Exposure to capsicum-oleoresin soil mixtures at concentrations of 1.50% and above significantly reduced mean soil contact time by 46% compared to placebo.
• Gophers exhibited increased grooming in the initial exposure, but this decreased over trials, attributed to reduced soil contact rather than habituation.
• Soil-digging behaviors were minimally affected by the presence of capsicum-oleoresin.

Conclusions:

• Capsicum-oleoresin soil mixtures are a feasible and effective repellent for deterring northern pocket gophers from inhabiting treated areas.
• The findings suggest that incorporating natural chemical irritants into soil can be a practical strategy for managing gopher-related damages.