Species traits associated with hosting and transmitting viruses
Nearly all the important human pathogens are zoonoses (transmitted from animals to humans, such as Lyme disease, rabies, & bird flu) or originated as zoonoses (like HIV), and more than 70% of these originated in wildlife. There is an urgent need to understand which species may be of the most concern. We have compiled databases of published accounts of viruses in bats and rodents and use statistical and network analyses to examine which species are important reservoirs and their characteristics.
Trophic cascade hypothesis for hantavirus outbreaks
Since its discovery in 1993, Sin Nombre hantavirus has infected more than 600 people and has killed more than 200. Humans contract this deadly disease when they come into contact with excrement from an infected rodent. We are examining the dynamics of this infection in the reservoir host, the deer mouse. Among other things, we are examining the relationship between climate, deer mouse population density, and Sin Nombre hantavirus prevalence in deer mice.
Large mammal predator-prey dynamics
The study of predator-prey population dynamics is dominated by simplified mathematical models that focus on the relationship between a single predator and prey, exemplified by the Isle Royale wolf-moose system. However, few systems are this simple in nature. Most assemblages contain multiple predator and multiple prey species, and their inclusion may spur novel and complex predator-prey interactions. We use mathematical models to represent multi-predator/prey population dynamics to understand what drives populations of large mammals and how to better manage them in the Rocky Mountain West.
Small mammal diversity and SNV
Sin Nombre hantavirus (SNV) appears to be less prevalent in the reservoir host, the deer mouse, when there is higher species diversity in the small mammal community- termed 'the dilution effect'. We are examining the role of host density, contact rates, and transmissibility in driving this relationship. Additionally, we are interested in how chronic stress may play a role, examining such questions as: What causes chronic stress (competition, climate, anthropogenic disturbance)? How is immunity affected? Are stressed mice more likely to acquire infection, or shed more virus if infected?
The importance of bats as reservoirs of viruses
Bats are the source of several deadly viruses, including Ebola and SARS, and this has led to speculation that bats may be special as disease reservoirs. From published data we are comparing bats to other host groups and examining the importance of bat traits, such as gregariousness and flight, in their propensity to host and transmit viruses.
Theory of disease ecology
We are broadly interested in the theory of infectious disease ecology. We use mathematical models to explore questions such as how disease ecology theory applies to systems not at equilibrium, inference from age-serology curves in hosts with various life histories, and how strategies to deal with seasonal availability of resources (hibernation and migration) affect disease dynamics.