Intellectual Merit: Why do we need sleep? The sleep-wake cycle is perhaps the most important biological rhythm in the animal kingdom, yet there exists no good explanation for its function. To date, most studies of animal sleep have been conducted on mammals in the laboratory. The proposed research will serve to examine wild sleep behavior in the House Sparrow. Birds are ideal models for studying the adaptive nature of sleep because of their strong seasonal behaviors (e.g. breeding) and overall sensitivity to local environmental changes. Examining how sleep-wake patterns and nighttime sleep characteristics change in response to seasonal variation in ecological factors such as temperature, daylight, and predation pressure, and in seasonal variation in behaviors such as foraging and aggression, will reveal which factors impact sleep the most. Identifying these external influences and the sleep characteristics that change in response will provide great insight into sleeps function. The proposed research is designed to explore the function of sleep by: 1) developing a non-surgical method of measuring sleep in small vertebrates, 2) examining the priority assigned to sleep by measuring sleep behavior and rest-activity patterns during each season of the year, and 3) establishing direct causal relationships between daytime behaviors and nighttime sleep characteristics. This study will: a) ask questions about sleep in an ecological context, b) utilize non-invasive measures to examine sleep in small vertebrates, and c) examine sleep behavior in wild animals.
Broader Impacts: This research involves the exploration of a fundamental yet unanswered question in biology. While we know that a certain amount of sleep is necessary, the exact function of this state remains unknown. Improvement in the quality and quantity of sleep in the human population at large requires the understanding of sleeps function. The broader impacts of this research also lie in the development of non-invasive methods that will expand the field of sleep research to investigators who were previously excluded due to the cost of electroencephalograph (EEG) equipment and the surgical skills required for EEG implantation in small animals. Further, this work will disseminate knowledge of sleep to the general public, as the field site is located next to a local convenience store where interactions with curious bystanders occur daily. Finally, this work will train young, scientific minds. As House Sparrows occupy the field site year round, it will be used as a place to train undergraduate students in basic behavioral observation techniques as part of Princeton Universitys Animal Behavior course. In addition, the two-year duration of this project will permit at least two undergraduate students per year to devise corollary projects investigating bird sleep for their senior theses.
