UCLA

Animals must deal with fluctuations in food availability across time. Long-term food hoarding species solve this problem by storing food in times of abundance. This turns a formally fleeting resource temporally concentrated at a singular time point, into a sustainable life source. Food-hoarding is a cognitively demanding task that requires individuals to account for competing variables to meet immediate and future needs. The first step in hoarding is the choice to eat or cache. This dissertation investigates the influence of environmental factors, individual experiences, and social competition on eat-cache decisions within a marked population of free-living western gray squirrels (S. griseus). Squirrels were presented with a feeding station that provided a choice between a cacheable in-shell item and a minced item only suitable for immediate consumption. Chapter 1 reviews recent studies on the socioeconomics and cognition of food hoarding in tree squirrels. These studies collectively inform the theoretical framework upon which this research is built. Chapter 2 examines the impact of time at varying scales. The eat-cache decision involves the interplay of factors such as satiety, food quality, competition, and predation risk. Results demonstrate that overlayed onto these considerations are seasonal variations in food abundance and immediate energy needs, along with the number of items already handled, and the assessment of item storability. Chapter 3 explores the influence of the presence of other squirrels on eat-cache decisions. Findings indicate a reduction in caching behavior when potential observers are present, highlighting squirrels' sensitivity to competition and their adeptness at integrating this information into their decision-making processes. Overall, this dissertation contributes to our understanding of the decision-making processes in a food-storing species through the collection of thousands of individual decisions in a natural setting.