What we do - research

Wildlife populations grow and shrink one individual at a time. 

As a result, the biochemistry, physiology, and behavior of individual animals are fundamental to their ecology. To improve our understanding of organismal biology and to provide a scientific basis for wildlife conservation, we study animal physiology in ecosystems from the poles to the equator, and from alpine regions to the deep sea.

Our projects include:

1) an organismal focus;

2) questions on the themes of metabolism, nutrient processing (assimilation, storage, use), and major physiological events such as reproduction;

3) inferences about animal performance, ecological interactions, and conservation.

Many of our projects have both lab-based and field-based components. For example, in Whiteman et al. 2019 (BioScience 69:658-668), we collected data from mice in a controlled experiment to demonstrate that our novel measurement of oxygen isotopes in body water (Δ17O) reflects water intake and energy use. We then measured Δ17O in samples from wild animals (e.g., black bears, Ursus americanus, in Minnesota, USA) to evaluate differences in the rates of use of water and energy.

Examples of recent and ongoing projects:

Influence of climate on energetics

This project evaluates the energy demands for basic physiological function and relates variation in this parameter to environmental conditions. Field work focused on Asiatic black bears (Ursus thibetanus) and sun bears (Helarctos malayanus) in Cambodia, with additional work using captive marsh rice rats (Oryzomys palustris) as a model endotherm.

Using Δ17O to trace water inputs and metabolism in wild animals

This project investigates how the new variable Δ17O can be used to understand the interaction between water balance and energy use. Validation studies focused on deer mice (Peromyscus maniculatus) and collared lizards (Crotaphytus collaris), with field studies of mule deer (Odocoileus hemionus) and other vertebrates.

Seasonal nutritional physiology in a semi-arid climate

This project applies a physiological perspective to seasonal nutrition in guanacos (Lama guanicoe) in Patagonia, Argentina, and pairs this with similar metrics measured in their primary predator (pumas; Puma concolor).

Nitrogen uptake and cycling in elasmobranchs

This project characterizes the novel ability of elasmobranchs (e.g., Atlantic stingrays; Dasyatis sabina) to take up environmental nitrogen and use it to build new body tissues. Because nitrogen is a limiting resource, this process may represent an adaptation that can release species from a nutritional restriction.

Organismal dynamics of energy storage and use across seasonal extremes

This project compares how polar bears (Ursus maritimus) obtain, store, and eventually use nutritional resources across “boom” and “bust” periods during the plentiful spring hunting season and the food-limited season of summer ice melt. Field work focused on the Southern Beaufort Sea subpopulation, near the northern coast of Alaska, USA.