I study disease ecology and animal ecology, with a focus on environmentally transmitted parasites that infect herbivorous mammals. Environmentally transmitted diseases tend to have complex interactions between hosts, parasites and the environment, which may affect the intensity or timing of disease outbreaks. My approach to studying these disease systems is to evaluate how variation in host ecology, pathogen persistence and environmental factors together contribute to patterns of
disease incidence. I have worked with gastrointestinal nematodes and coccidia, and the anthrax bacterium, Bacillus anthracis
, during the course of my postdoctoral and PhD research. The focal host species have included plains zebra (Equus quagga
), springbok (Antidorcas marsupialis
), elephant (Loxodonta africana
), blue wildebeest (Connochaetes taurinus
) and gemsbok (Oryx gazella
My current postdoctoral research evaluates how and when Bacillus anthracis
is transmitted to grazing wildlife in Etosha National Park, Namibia. This study, funded primarily by the National Science Foundation, was initiated in 2010 and will continue until 2014, with three main field components. Firstly, I examine how the persistence of B. anthracis
spores in soil and on grasses at anthrax carcass sites varies in relation to soil characteristics, grass morphology and environmental
conditions. Secondly, I examine how nutrients released into the environment from anthrax carcass sites alter soil fertility, grass biomass and grass quality, and the duration of this effect. Finally, I use motion-sensing camera traps to compare herbivore visitations and foraging behaviors at carcass and control sites, and how these change seasonally and with time since animal death. The results of these studies will be combined to assess if the seasonality of anthrax incidence in
grazing hosts can be predicted based on seasonal changes in exposure to B. anthracis
at locally infectious carcass sites. My previous postdoctoral work through UC Berkeley assessed how seasonal changes in herbivore soil ingestion, nutrition, diet selection and foraging efficiency may relate to the seasonality of anthrax infections, in part by co-supervising two Master's students at the University of Namibia.
For my Ph.D. from the UC Berkeley, I studied gastrointestinal parasites infecting herbivorous hosts in a semi-arid savanna ecosystem of Etosha National Park, and examined how host-parasite relationships are modulated by host ecology, parasite interactions and environmental variability. I am also collaborating on projects linking gastrointestinal parasitism to co-infection with other parasites/pathogens and host individual variation in disease susceptibility. This includes relating MHC diversity in plains zebra to parasite-mediated immune tradeoffs in response to nematode versus ectoparasite infections, and determining how immune parameters, stress and reproductive hormones relate to rates of parasitism and the timing of anthrax coinfections in zebra and springbok.
I volunteered as a field/research assistant for a variety of research projects in New York, California and South Africa after graduating from Cornell University. I fell in love with southern Africa, and started my research career in Hluhluwe-iMfolozi Park, located in KwaZulu-Natal, South Africa, where I did Master's research through the University of the Witwatersrand. For my Master's I studied the activity patterns of African buffalo (Syncerus caffer
). This research was conducted in the context of a larger bovine tuberculosis project, to understand the behavioral processes behind why male buffalo moved in and out of breeding and bachelor herds.
Ongoing collaborations extend my primarily field-based ecological research in new directions, such as assessing climate effects on animal populations and disease dynamics, developing methods to assess how animal movement and home ranges change over space and time, developing methods and software for managing the deluge of data from camera trap studies, and studying pathogen diversity, strain competition and micro-evolution of B. anthracis
. I am also co-supervising an MSc student
at the University of Namibia to study if dust bathing behavior may put herbivores at risk for inhalational anthrax. This project uses a combination of camera trap and behavioral observations and a microbiological survey for B. anthracis
in dust bath soils.
A female springbok (Antidorcas marsupialis) nursing her lamb.