Exploring the Efficacy of Prairie Dog Boundary Management and its Application Toward Density Control

Abstract

Despite providing numerous ecosystem services, black-tailed prairie dogs (Cynomys ludovicianus) can negatively impact livestock production, presenting a challenge for rangeland management. Lethal control along public-private boundaries is one approach to balance competing stakeholder desires. A novel approach to reduce but not eliminate prairie dogs on public land (“density control”) was proposed to increase forage availability for livestock while maintaining other prairie dog-associated ecosystem services. Little research on this approach exists, but we posit that where boundary management leads to population reduction but not elimination (the case on many U.S. Forest Service National Grasslands), boundary management is one form of density control. We reviewed the literature on boundary management and density control, and then evaluated boundary management as one form of density control using a before-after control impact design in the Thunder Basin National Grassland of Wyoming. We found scant literature describing either management approach; resources reporting efficacy were typically management documents not found in traditional literature searches. Boundary management did not reduce adult prairie dog density relative to untreated areas (β_treatment = 0.28, 95% CI [−0.28, 0.85]), but pup numbers were lower following treatment (β_treatment = −1.43, 95% CI [−2.12, −0.79]). Bird communities and overall plant biomass were largely unaffected by treatment, although forb biomass was 5x higher on sites that experienced treatment. Forbs often increase within the months following prairie dog reductions; this paired with high numbers of prairie dogs on treated areas in the following spring indicate treatment was temporarily effective but that prairie dogs rapidly re-colonized. Studies of these management approaches are rare and difficult to access by managers, which is concerning because we found little support for positive impacts (i.e., increased forage) of density control at local scales. While it may be effective for small colonies, boundary management that results in partial lethal control (density control) may be economically and ecologically ineffective.