1995 Ph.D. in Biology, University of California, Santa Cruz, CA
1992 M.S. in Marine Sciences, University of California, Santa Cruz, CA
1987 B.S. in Applied
Biology, Georgia Institute of Technology
Professor, Sonoma State University, 2008 - present.
Associate Professor, Sonoma State University, 2003-2008.
Assistant Professor. Sonoma State University, 2000-2003.
Assistant Research Ocean Scientist, University of California, Santa Cruz, 2001-2004.
Assistant Research Biologist. University of California, Santa Cruz, 1997-2001.
Postdoctoral Researcher. University of California, Santa Cruz, 1995-1997.
Research Interests: Comparative Physiology of Vertebrates; Physiological Ecology; Bioenergetics; Behavioral Ecology; Biology of Marine Mammals.
Research Program: My research is focused on the physiological and
behavioral ecology of pinnipeds, seals and sea lions.
My approach is to integrate physiology and behavior with the aim of addressing
ecological theory. I am investigating physiological factors that impact the
reproductive and foraging strategies used by marine predators. Much of my
current research is focused on the physiology and behavior of northern elephant
seals. These investigations include both field and laboratory studies. My field
research focuses on studies of fasting physiology and reproduction when seals
are hauled out on land to breed and diving physiology and foraging when animals
are at sea. My graduate students are exploring a wide variety of research
areas including fasting physiology, foraging behavior and life history strategies.
My lab has a strong collaborative relationship with the
This work is sponsored by NSF in collaboration with Dorian Houser and Cory Champagne from the National Marine Mammal Foundation and others. We investigate the metabolic adaptations that allow animals to go for weeks and months without food and water while undergoing costly activities like breeding. These studies use cutting edge metabolic tracer technologies and 'omics approaches to better understand the regulation of metabolism under the constraints of extreme fasting and include investigations of the endocrine regulation of fasting.
We've found that, unlike other animals, elephant seals maintain high rates of glucose production while fasting, mainly by recycling glucose carbon through the Cori Cycle in association with high rates of pyruvate and TCA cycle activity. These features allow elephant seals to provide fuel for glucose dependent tissues while maintaining high rates of fat oxidation without significant accumulation of ketoacids or use of protein from vital organs. These unusual features allow elephant seals to exhibit some of the highest sustained metabolic rates during fasting found in nature.
This work is sponsored by NSF and many others. In collaboration with Dan Costa's lab at UCSC, my lab participates in the Tagging of Pacific Predators (TOPP) project. My interest is in the foraging strategies used by elephant seals and other marine predators and how these strategies vary with intrinsic state variables (like mass or age) and ocean climate. These studies also integrate with our conservation physiology research which seeks to understand how foraging effort and success influences reproductive effort, stress and health. These studies have also included work on the foraging behavior of several Antarctic pinnipeds and their responses to the rapidly changing climate.