Meeting Abstract
The endocrine stress response allows vertebrates to appropriately react to stressful stimuli such as predator presence, low food availability, and social instability. By releasing glucocorticoids (GCs) into the bloodstream, the endocrine stress response essentially redirects energy from unnecessary physiological processes (e.g. reproduction, digestion) to those immediately necessary for survival (e.g. energy mobilization, heightened fight-or-flight response). Ectoparasitism may be one such stressor that elevates GC levels, yet the relationship between ectoparasite numbers and the endocrine stress response has not been well defined. We measured ectoparasite numbers and GC (cortisol) concentrations in two ecologically and geographically distinct populations of free-living degus (Octodon degus) in central Chile. Exotic fleas have been identified as the predominant ectoparasites in one population. Between populations, there may be variation in the ectoparasite species and their bacterial communities, potentially influencing cortisol levels. Thus, our aim is to explore the relationship between cortisol levels and ectoparasitism, including their associated bacterial communities, in two populations of degus.
