Ecological systems typically include many species that interact in complex networks of connections. We seek to determine the key ecological connections that govern the dynamics of Lyme disease risk to humans. Prior observational and experimental studies in oak forests suggest that risk of human exposure to Lyme-disease bearing ticks may be predictable almost two years in advance based on acorn production. Production of acorns - a high quality food for wildlife - by oaks varies dramatically among years. High abundance of acorns in the fall enhances survivorship, reproduction, and population growth of white-footed mice, resulting in high mouse density the following spring and summer. Newly hatched larval ticks feed more successfully, and acquire the Lyme disease bacterium more efficiently, from mice than from other hosts. Therefore, we predict that the higher the abundance of mice, the greater the expected abundance of infected ticks capable of transmitting disease to humans. Because mice are also voracious predators on eggs of ground-nesting songbirds, these rodents appear capable of regulating population size of species such as Veeries and Wood Thrush. We will test these expectations over the next five years.
Results of this project are used in Ecology and Mammalogy textbooks and for public education (local and regional presentations and newspaper/magazine articles). The proposed research has strong practical implications because it will facilitate the prediction of times and places of high disease risk. As such, it promotes both the realized and perceived utility of ecology for human welfare.
