Disease Ecology: Facultative Host Response to Infection
Stressors such as parasitic infection represent central components of an animal’s ecology. Pathogenic infection can have detrimental effects on hosts, including negative impacts on immunocompetence, energetics, survival and reproductive ability. In addition, hosts may alter their physiology, behavior and life history to ameliorate the costs of infection. I have a broad interest in ecoimmunology, which is the field that examines how a host’s immune system is related to evolutionary traits (e.g. lifespan, body size, coevolutionary interactions with hosts) and current ecological state (e.g. age, sex, parasite exposure). Much of my empirical research has focused on Peromyscus mouse hosts infected with spirochete bacteria or schistosomes. Deer mice (Peromyscus maniculatus) infected with a trematode blood fluke (Schistosomatium douthitti ) develop a chronic infection and have reduced survival. In response to infection, mice increase their current reproduction, producing offspring of higher mass and lifetime fitness. This is likely an adaptive, facultative response by the host to produce more offspring immediately in the face of reduced future reproduction caused by infection. More recently, I have explored the disease ecology Borrelia burgdorferi, which is a spirochete that causes Lyme Disease in the northeastern USA. White-footed mice (Peromyscus leucopus) are an important, wild reservoir for the bacterium. Black-legged ticks transfer the parasite among a number of vertebrate species, importantly among mice and humans. Although mice mount an immune response against the bacterium, they are not obviously impacted by infection. However, when looking more closely, it seems that infection or a simulated infection leads to altered activity patterns and foraging behavior. These modest changes in mouse behavior can have extensive implications for mouse population growth, disease ecology and community ecology.
Collaborators: Dustin Brisson, Maria Gomes-Solecki, Richard Ostfeld, Andrea Previtali, Dan Warner, Suzanne McGaugh, Anne Bronikowski, Roberta diTerlizzi