The Effects of Simulated Competition on Foraging Behavior in Sciurus carolinensis

Ecological communities are often shaped by competition between individuals for a shared limited resource (Rohde 2011). Competition may be between individuals of the same species (intraspecific competition) or between individuals of different species (interspecific competition). In forest communities, squirrels and other rodents rely on the same food sources and are still able to coexist. Gray squirrels (Sciurus carolinensis) have been known to strategically forage in order to maximize energy intake and minimize exposure to predators (Lima et al., 1985). However, it is unclear if S. carolinensis take into account competitors when calculating optimal foraging levels. Sciurus carolinensis are generally not aggressive towards each other, with the exception being during autumn, in order to deter immigrants from invading (Koprowski, 1994). Otherwise, territoriality is uncommon, and often home ranges overlap (Lewis, 1980). Therefore, S. carolinensis are typically expected to compete exploitatively and not through direct interference. There is also evidence that a social hierarchy within species can be constructed based on body size, which discourages overt aggression (Gurnell, 2004). Nonetheless, the influence of competitors on the foraging habits of S. carolinensis is not fully understood. Initially, two preliminary studies were conducted in order to assess the feeding habits of local squirrels. These data, although insignificant, was used in order to design an experiment to evaluate the effects of competition on the foraging habits of S. carolinensis. Because S. carolinensis are not known to be offensive, we hypothesize that these squirrels will be more likely to forage from a vacant food source than a food source with competitors present. Our goal is to better understand the dynamics of competition in a population of S. carolinensis.