Aptitude in American Alligators: ecological factors affecting cognition and behavior
American alligators (Alligator mississippiensis) possess flexible cognitive abilities. Given these cognitive abilities, we hypothesized the capacity for flexible learning is significantly affected by ecological factors such as environmental temperature and contaminants. Additionally, we reasoned that the same ecological modifying inherent cognitive capacities also shape other traits in adaptive ways. In order to explore these relationships we utilized three separate studies divided between four chapters. In the first three chapters our research employed serial-reversal experiments to quantify the total number of errors in a series of discrimination problems to investigate the effect of temperature and environmental contaminates on inherit cognitive abilities. Chapter 4 is devoted to an investigation of the effect of these same environmental contaminates on thermoregulatory behavior and metabolism. Specifically, experiments presented in chapter one investigated the visual learning abilities of juvenile American alligators in order to determine the degree of complex learning. Chapter 2 describes the effect of temperature on the performance of juvenile American alligators in a spatial discrimination task by tasking animals to complete a series of ten reversal at two environmentally relevant temperatures. The successful development of both protocols led us to ask the question of whether or not we could apply a similar behavioral assessment of learning and memory abilities in animals exposed to environmental contaminants. Recognizing that organochlorines still contaminate the waters inhabited by American alligators, Chapter 3 explores the affect in ovo exposure to DDE has on learning and behavior in hatchling American alligators. Specifically, we investigated if DDE affects cognition of American alligators by comparing the performance of individuals that were exposed as embryos to the performance of control individuals in a spatial discrimination task. Organochlorines, such as DDE, can bioaccumulate and are therefore particularly problematic for top predators. Therefore, it is important to know if standard metabolism or preferred body temperatures are perturbed by DDE exposure because these changes may affect the overall health of animals, their reproductive success, and the health and growth rates of hatchlings. Therefore, in Chapter 4 we designed a study to measure changes in the thermoregulatory system and metabolism of animals exposed to DDE.