Meeting Abstract
P3.24 Monday, Jan. 6 15:30 Neither chronic stress nor a costly-life history stage affect wound-healing in European Starlings (Sturnus vulgaris) DURANT, SE*; DE BRUIJN, R; TRAN, M; ROMERO, LM; Oklahoma State Univ; Tufts Univ; Tufts Univ; Tufts Univ sarah.durant@okstate.edu
Chronic stress, potentially through the actions of corticosterone, is thought to have negative consequences for immune function in birds. However, chronic stress may also influence allocation of energy, ultimately shifting resources away from the immune system. If so, then the effects of chronic stress on immune responses may be greater during costly life history stages like molt. To test whether the effects of chronic stress on immune responses differ during life history stages, we exposed both molting and non-molting starlings to 28 d of chronic stress. We minimized disturbance experienced by control birds. Prior to the start of chronic stress we collected baseline, stress-induced, Dex-induced, and ACTH-induced blood samples to determine whether corticosterone correlated with wound healing rates. After 8 days of exposure to chronic stress, we wounded both control and chronically stressed birds and monitored healing daily. We also monitored body mass of birds every two days. Contrary to work on lizards and small mammals, all birds, regardless of stress or molt status, fully-healed wounds at similar rates. Body mass data suggest that chronically stressed birds initially lost weight after wounding, whereas control birds did not. However, about 6 d post wounding both control and chronic stress birds continually gained weight throughout the rest of the study. Increased body mass could suggest compensatory feeding to offset energetic or resource (e.g., proteins) demands of wound healing. Interestingly, pre stress baseline corticosterone concentrations positively correlated with healing rates. Although chronic stress did not inhibit healing, our data suggest that corticosterone may play an important role in mediating healing processes.
