9222369 Rashotte To survive in vastly different environmental conditions, such as occur across the seasons of a year, animals and humans must have good strategies for keeping their energy expenditure in balance with energy intake. Endothermic (warm-blooded) animals, including humans, face the most serious problem because of the need to maintain high body temperature and metabolic rate. This project will use advanced experimental methods to study in greater detail than has previously been possible the ways a very widely distributed and, in survival terms, highly successful endothermic animal (the pigeon) manages to cope with the range of environmental conditions in which it is found. By using unique computerized environments, this project will vary the ambient temperature, the difficulty associated with finding food, and the length of the daily light-dark cycle in ways that simulate some natural conditions for these animals. The experimental situation in which they live is highly instrumented to record their use of strategies for achieving energy balance through changing their feeding behavior, body temperature, metabolic rate, and overall daily activity level. In some cases, the environmental conditions are specifically designed to elucidate factors that influence which of these strategies are brought into play when the environment changes. This project is unique in providing new information about the changing interplay of these strategies across the animal's normal daily cycle of activity and inactivity, and in providing such data from animals which are free to adopt varied combinations of these strategies over the long term as they become acclimated to new environmental conditions. The outcome of this research is likely to deepen our knowledge of the survival strategies used by endothermic animals to cope successfully with varied environmental conditions. With the new and detailed information in hand which this project promises to provided, it shoul d be possible to encourage new lines of future research on specific brain and hormonal bases for these strategies. A thorough understanding of the relationship between changes in environmental conditions and the appearance of certain survival-related strategies involving feeding, metabolism, activity, and energy balance will contribute to basic knowledge in the life sciences and may ultimately have relevance for problems as diverse as the proper management of animal habitats and seasonally related human disorders involving metabolism and feeding.
