IRCEB: The Life History-Physiology Nexus--Constraints on the Evolutionary Diversification of Avian Life Histories

University Of Missouri-Saint Louis, Saint Louis MO

Investigators

Abstract

This project brings together a team of ecologists and physiologists to investigate how physiological mechanisms constrain the evolution of parental investment and self-maintenance in tropical and temperate environments. Life-history theory predicts that long-lived organisms should allocate more resources to enhancing survival, thereby protecting future reproduction, at the expense of current reproduction. Many of the predicted responses of physiology and behavior are controlled by endocrine and immune system mechanisms that establish incompatible physiological states and limit individual responses of organisms and evolved responses of populations. This collaborative study will compare related species of birds living in contrasting tropical and temperate environments to determine population parameters (adult survival and reproductive rate) and physiological and behavioral responses. Incorporating a strongly developed student-training component in the project, measurements will include activity, metabolism, health status, and endocrine profiles in the field, and metabolism, hormonal stress response, and immune system response in the laboratory. Analysis and interpretation of these data will relate variation in life-history attributes to phylogenetic relationship, region, and ecological measures of habitat, diet, and predator environment. This project is unique in that it integrates studies in ecology, physiology, and demography to focus on major patterns of diversification of life histories.