NON-TECHNICAL ABSTRACT Proposal Number 9805571 PI: Creel, Scott This study will clarify how social status affects behavioral and physiological responses to stress in free-living wolves. In studies of captive rodents and primates, social subordinates often show long-term increases in the secretion of adrenal glucocorticoids, a primary constituent of the stress response. Recent studies of social birds and mammals, conducted in the wild and captivity, show that glucocorticoids are sometimes higher in dominant individuals than in subordinates. It is not yet clear what variables determine these differences among species. This research will collect non-invasive measurements of glucocorticoids from fecal samples collected from free ranging wolves, and will quantify rates of aggression and other social behaviors, to determine relationships between dominance, aggression and the glucocorticoid stress response. All animals, including humans, face a variety of stresses, ranging from physical conditions like cold or hunger to psychosocial stress due to aggressive interactions. The primary physiological response is an increase in the secretion of glucocorticoids, regardless of the specific stressor involved. This response is beneficial in the short term, but is harmful if prolonged (e.g. energy metabolism becomes inefficient, the immune system is impaired, and neurons in the brain atrophy). Because glucocorticoids have strong effects on reproduction and immunity, the study of social stress has broad ramifications for disciplines ranging from evolutionary biology to human stress management.
