Our research interests
We try to understand what animals eat and why. We then use foraging behavior to study individual animals, species’ populations, and entire ecosystems.
Current Research Projects
In Mozambique’s Gorongosa National Park as well as protected and agricultural lands in California, we use DNA metabarcoding to study what animals eat. This means we handle a lot of poop, which is the raw material from which we can extract DNA and reconstruct diets. Primarily, we focus on ungulate herbivores (from zebra to pronghorn to cattle) and the intricacies of their plant diets. A core question across this research is: what are the aspects of plant chemistry that herbivores use to select foods and how do those indicators relate to individual nutritional condition? Ultimately, our aim is to develop and validate predictive models of herbivore foraging behavior that can guide population management.
We also dabble in carnivore diets, particularly through our work in Mozambique. In these projects, we are aiming to understand how carnivore diets adapt to novel environments by studying either translocated or rehabilitated populations.
Linking foraging behavior with individual- and population-level consequences relies on our ability to accurately measure an individual’s body condition. For large animals, like ungulates, this can requires invasive or destructive sampling methods.
In collaboration with engineers at UC Merced, we are developing a platform for automated measurement of body mass and size in large animals. This platform will allow scientists and ecosystem managers to track body condition non-invasively across populations in real time and also provide data on population age structure and overall health.
Large herbivores must navigate dramatic changes in quality and availability of plant foods as seasons shift from summer to winter or wet to dry. Using fine-scale temporal sampling of diet composition across entire communities of herbivores, we are investigating how dietary-niche overlap among species changes with the seasons. Alongside collaborators at Wake Forest University and in The Netherlands, we also study how the seasonal wildebeest migration in the Serengeti alters niche overlap among non-migratory species and based on the water dependence of those species.
We are currently developing a project with collaborators at Montana State University, the University of British Columbia, and Princeton University to study how seasonal flooding in Gorongosa National Park alters niche overlap among herbivore species, with the community crowded into woodland habitat in the wet season and dispersed across the now-dry floodplain in the dry season.
Through the sheer size of their appetites, large herbivores have inordinate impacts on the ecosystems they are part of. We are studying how their presence alters ecosystem-wide processes. In previous work, we showed (alongside collaborators at the University of Florida) that the presence of large herbivores greatly diminishes floral resources for pollinators.
Our current work explores the impact of large herbivores on ecosystem-wide plant productivity and the additional impacts of their dung deposition on the broader community.