Professor Karasov is interested in the physiological ecology of terrestrial vertebrates, particularly the ecological implications of how they process energy, nutrients, and toxins.

Nutritional ecology

The relationships between the nutrient requirements of animals and the nutritional value of their food resources potentially affect diet selection, productivity, and survival. Professor Karasov and his students have performed laboratory and field studies on the nutritional ecology of several species of mammals and birds in order to explore the significance of nutrition in their ecology. This work includes studies of how antiherbivory chemicals in plants affect food selection, digestion, physiology, and population biology of herbivores.

Digestive ecology

Vertebrates differ considerably in the types of foods that they consume, but little is known of the physiological adaptations required for effective utilization of alternate food types. Professor Karasov and his students are studying the digestive physiology of animals with different dietary habits (such as carnivores, herbivores, omnivores, frugivores, and nectarivores) and also how digestive features vary over the short-term (i.e., within a species) and between species (i.e., over evolutionary time).

Ecological energetics

All organisms need energy, and many activities of animals are centered around how to get, process it, and conserve it. Professor Karasov and his students are studying the energetics of free-living animals using doubly labeled water, micrometeorology, telemetry, and direct observation of behavior. They are documenting the physical, physiological, and behavioral factors which affect energy intake and expenditure, and the relationships between foraging behavior and reproductive success.

Wildlife Toxicology

Animals living in or feeding from the Great Lakes are exposed to a number of pollutants, notably halogenated organic compounds and heavy metals. Professor Karasov and his students are participating in studies to determine the level of exposure of fish-eating birds and amphibians, and whether the exposure causes physiological and behavioral dysfunction and effects on population biology.

International and Other Activities

Professor Karasov has served as graduate advisor for students from around the world. Additionally, he has lectured, taught and done research in a variety of locations such as: Argentina, China, Israel, Taiwan, United Kingdom, and South Africa.

Professor Karasov has served on the editorial boards of several journals: Functional Ecology (2002-2004), The Auk (2000-2004), Physiological and Biochemical Zoology (1998-2001), Ecology (1995-1997), and American Journal of Physiology (1993-2001).