The role of stress in natural populations

The objective of my research is to understand the role that stress plays in nature, both in terms of individual effects and population consequences. The stress axis is one of the key physiological systems that mediates the relationship of an organism with its environment, acting both on a daily basis to affect physiology and behavior and in response to acute and chronic environmental stressors.  We use the tools of endocrinology, animal physiology and metabolism, epigenetics, population ecology, and behavioral manipulations to study the stress axis. Our primary research models are wild mammals in northern Canada. Our goals over the next five years focus on three main areas: a) Maternal programming through stress-induced epigenetic changes resulting in long-term population effects. The effects in snowshoe hares can affect the ecosystem dynamics of the entire 5,000,000 km2 boreal forest in Canada. Our continuing work in the Yukon on snowshoe hares focuses on epigenetic changes caused by the stress of high predation risk. b) Buffering of maternal stress during and after pregnancy: Of the 19 orders of mammals, few have been studied and of those that have, some but not all, appear highly vulnerable to maternal programming in nature. c) Adrenal steroids and life history processes: These have evolved not only to deal environmental stressors, but also unique ecological problems such as nonbreeding season territoriality and preparation for hibernation. We are experimentally examining the role of adrenal androgens and their precursors in pikas and arboreal and ground squirrels.