Assessment of adrenocortical and gonadal hormones in male spider monkeys (Ateles geoffroyi) following capture, restraint and anesthesia.

The spider monkey (SM) (Ateles geoffroyi) a New World primate species native to Mexican forests, has become endangered in the wild due to environmental perturbations. Little is known about adrenal function and its relationship to reproduction in this species. Our objectives were to assess serum glucocorticoid (GC), mineralocorticoid (MC) and testosterone concentrations in captive SM and evaluate adrenal and testicular responses to potentially stressful animal handling procedures. Seven adult males, housed in a single mixed gender group in an off-exhibit enclosure at the University Park were captured for anesthesia every 2 months over a 1-year period. Blood samples were collected from each male at three time points: (1) ∼5-10 min after ketamine injection in the outdoor enclosure; (2) ∼2 hr later following animal transport to the laboratory and immediately after tiletamine-zolazepam injection; and (3) ∼20-30 min following the second anesthetic injection. Serum samples were frozen and later analyzed for cortisol, corticosterone, aldosterone and testosterone via radioimmunoassay. Cortisol was the primary GC detected in SM serum with much higher mean concentrations than for corticosterone. Capture, restraint and anesthesia resulted in significant increases in both cortisol and corticosterone concentrations. Whereas aldosterone concentrations were unchanged by animal handling procedures, testosterone concentrations significantly declined under anesthesia over time. In summary, these results provide data for the main adrenocortical hormones in male SM and characterize their acute adrenal responses to potentially stressful handling and anesthesia procedures. Our findings also suggest an interaction between acute increases in corticosteroids and decreased concentrations of serum testosterone.

Stress in wildlife species: noninvasive monitoring of glucocorticoids.

Depression and stress are related pathologies extensively studied in humans. However, this relationship is not well known in animals kept in zoos and even less known in wild animals. In zoo animals, acute and chronic stress caused by difficulties in coping with stressors such as public presence and noise, among others, can induce the appearance of repetitive pathological behaviors such as stereotypies, many times associated with organic pathologies that deeply affect their health and welfare. In the wild, factors such as deforestation, habitat fragmentation, lack of food and water, and human disturbances are potential causes of acute and chronic stress for the resident fauna. Glucocorticoids (GC) have been extensively used as stress indicators in many species including humans. Since chase and handling of wild animals immediately raise their GC serum levels, noninvasive methods have been developed to assess stress without interference caused by sample collection. The hormones and their metabolites can be measured in various body fluids and excreta and detect basal feedback free hormone concentrations as well as the response to ACTH and handling. In order to study the influence of disturbing factors we have measured GC as stress indicators by noninvasive techniques in dolphins and felids (ocelots, jaguarundis and margays) and cortisol and testosterone in spider monkeys.