Meeting Abstract
Resource mobilization and reallocation is a major endpoint of the physiological response to acute stress. However, energy metabolites have not been the focus of most field studies. Here we characterized the glycemic and free fatty acid (FFA) response to acute-handling stress in a breeding, free-living, population of Mountain Dark-eyed Juncos (Junco hyemalis) in Mono County, CA. Juncos were trapped in seed-baited Potter traps at Tioga Pass Meadow from May 17 to June 20, 2018, coinciding with territory establishment and the early nesting period. Blood samples were collected at 0, 15 and 30 min post-capture. Blood glucose levels were higher than baseline at 15 min (43% increase) and 30 min post-capture (67% increase). FFA levels were also higher than baseline at 15 min (29% increase) and 30 min post-capture (22% increase). Predictors of energy mobilization including date, scaled body mass, fat score, hematocrit, sex, and bleed delay time were modeled using backward and forward stepwise regression. Analysis showed that juncos mobilize glucose and FFA in response to acute handling stress, and these responses are best modeled when scaled mass, abdominal fat, and initial glucose response from baseline to 15 min are included as predictor variables. These results suggest that energy mobilization capacity is influenced by measures of body condition.
