On the ground and from above: a multi-scale analysis of the factors influencing small mammal populations in a restored tallgrass prairie

Background/Question/Methods

Tallgrass prairies are among the most globally threatened ecosystems, with only one percent of the historical extent remaining. Prairie restoration is an essential strategy to preserve biodiversity and reestablish threatened species. Practitioners use management tools to shift the landscape context of prairie restoration sites, such as prescribed fire and land cover change. Managers can also impact the landscape connectivity and edge proximity of certain areas through the use of mowed driving lanes. Nachusa Grasslands, a prairie restoration preserve in north-central Illinois, presents a unique opportunity to study the impacts of management on landscape ecology of small mammals due to the long-term nature of the site. Small mammal live trapping was conducted over six years at 20 sites. During those six years, different portions of the preserve were burned annually, the preserve area increased, and the land cover changed. We used various metrics of management practices and land cover to spatially analyze species-specific patterns of small mammal populations. Our objective is to gain a better understanding of the landscape ecology of small mammals in restored tallgrass systems and to fill a gap in the literature by specifically examining the landscape impacts of tallgrass prairie restoration on a ubiquitous prairie clade.

Results/Conclusions

Preliminary results support previous conclusions about species-specific impacts of local- and landscape-scale factors on small mammals. Both as a categorical and quantitative variable, deer mice (Peromyscus maniculatus) were positively associated with prescribed fire, while prairie voles (Microtus ochrogaster) were negatively associated. Visual inspection of the number of captures at individual traps within trapping grids revealed species-specific patterns associated with habitat types, with captures of white-footed mice (Peromyscus leucopus) grouping at traps closest to wooded areas and prairie vole captures clustering away from paved or gravel roads. This new work largely supports conclusions from previous research in remnant prairies regarding species-specific relationships with disturbance. Since small mammals are central in tallgrass prairie food webs, the management of these species can have significant ripple effects on the community as a whole. Understanding the impacts of landscape context change on small mammals will support land managers in making more informed decisions to best conserve this rare ecosystem.