Hot and bothered: Tick attachment and white-footed mouse stress in a burned landscape

Lyme disease, caused by a pathogen transmitted by the blacklegged tick (Ixodes scapularis), is an increasing problem across the U.S. with an estimated 476,000 human cases annually. Concurrently, ongoing habitat fragmentation, forest management policy, climate change, and other environmental transformations continue to support key tick hosts and habitats. Controlled burns, which have the capacity to reduce host habitat and leaf litter refuge for ticks, have been investigated as a mechanism for tick control. The immediate reduction of tick populations following fire has been investigated to some extent but has largely focused on Amblyomma americanum. However, there is more to learn about tick-host interactions following these burn events. In the northeastern United States, white-footed mice (Peromyscus spp.) are an important reservoir for the pathogen that causes Lyme disease, Borrelia burgdorferi. The purpose of this study is to evaluate the effect of historic prescribed burns on white-footed mouse populations, stress-indicating hormone levels, and blacklegged tick burdens in these same forests. Mice will be trapped in three Pennsylvania forests using Sherman live traps. Trapping will occur in areas treated with a prescribed burn within the past three years and in paired, non-burned control sites. Ticks, tissue, mouse morphometric data, and mouse hair will be collected from captured mice. Hair will be analyzed for corticosterone levels using commercially available assays. Understanding how host population and tick-host relationships change in response to large-scale landscape change can help develop Lyme disease prevention methods and inform land managers about tick-borne disease risks across an ever-changing landscape.