White-footed mouse (Peromyscus leucopus) response to restoration of grassland alvar

Grassland alvar is a rare plant community that occurs throughout North America and northern Europe, and may require control of encroaching vegetation to be maintained or restored. We evaluated the hypothesis that restoration techniques used to restore the alvar ecosystem do not lead to declines in small mammal abundance. More specifically, we used a Before-After Control-Impact (BACI) design to compare how two methods of vegetation control, prescribed burns and mechanical removal, affected small mammal populations. The restoration was conducted beginning in 2019 on Pelee Island, Ontario, Canada. Live trapping of small mammals and associated vegetation sampling were conducted before and after on treatment and control locations. The only small mammal species to be caught during the study was the white-footed mouse ( Peromyscus leucopus (Rafinesque, 1818)), which had an observed decrease across all treatment sites and the control site. Generalized linear mixed effects models demonstrated that the main effects of treatment and year best explained mouse abundance at the site level. Interannual variability appeared to explain more variation in mouse abundance than treatment effects. Our study did not provide strong evidence that the vegetation control measures we employed might limit white-footed mouse abundance.