Local drivers of blacklegged tick ecology in an emergent area for tick-borne disease

As the geographic range and population density of the blacklegged tick (Ixodes scapularis) expands in North America, factors including host abundance and human-induced land-use changes can play a contributing role in this expansion. Small mammal hosts serve as important reservoirs of tick-borne pathogens, with Peromyscus leucopus (the white-footed mouse) often considered the principal reservoir. A sympatric species, P. maniculatus (the deer mouse), is a competent reservoir of tick-borne pathogens, although its role in the maintenance of these pathogens has not been widely characterized. Anthropogenic land-use changes can alter the suitability of fine-scale tick habitat, potentially impacting the density of ticks both on and off-host. In this study, we tested the hypotheses that tick infestation and tick-borne pathogen prevalence differ between two Peromyscus spp., and across land-use types within an emergent area for tick-borne disease. We conducted small mammal and tick collections across three land-use classifications within the Penobscot River Valley in Maine. While both Peromyscus spp. serve as hosts for immature I. scapularis, P. leucopus was more frequently parasitized and exhibited higher mean tick infestation intensity. Conversely we found that P. maniculatus was more frequently infected with B. burgdorferi than P. leucopus. We examined I. scapularis abundance and infection prevalence across both a habitat and land use gradient, confirming the importance of fine-scale habitat availability but finding less support for the impacts of specific human activities within similar sites. These findings provide more insight into the tick-borne disease maintenance cycle in an emerging region.