A generalized fecal glucocorticoid assay for use in a diverse array of nondomestic mammalian and avian species.

Noninvasive fecal glucocorticoid analysis has tremendous potential as a means of assessing stress associated with environmental disturbance in wildlife. However, interspecific variation in excreted glucocorticoid metabolites requires careful selection of the antibody used in their quantification. We compared four antibodies for detecting the major fecal cortisol metabolites in yellow baboons following (3)H cortisol administration, ACTH challenge, and HPLC separation of fecal glucocorticoid metabolites. The most effective antibody (ICN corticosterone RIA; Cat. No. 07-120102) demonstrated relatively high cross-reactivities to the major cortisol metabolites present in feces during peak excretion, following both radiolabel infusion and ACTH challenge. This same antibody also detected increased fecal glucocorticoid metabolites after ACTH administration in the African elephant, black rhinoceros, Roosevelt elk, gerenuk, scimitar-horned oryx, Alaskan sea otter, Malayan sun bear, cheetah, clouded leopard, longtailed macaque, and northern spotted owl. Results suggest that (1) fecal glucocorticoid assays reliably detect endogenous changes in adrenal activity of a diverse array of species and (2) where comparisons were made, the ICN corticosterone antibody generally was superior to other antibodies for measuring glucocorticoid metabolites in feces.

Behavior, appetite, and urinary cortisol responses by adult female pigtailed macaques to cage size, cage level, room change, and ketamine sedation.

Pigtailed macaques (Macaca nemestrina) and longtailed macaques (M. fascicularis) show behavioral, ecological, and possible temperament differences, and their responses to the laboratory environment might therefore be quite different. We tested pigtailed macaques under the same conditions that were investigated in a previous study with longtailed macaques, using the same comprehensive set of physiological and behavioral measures of stress. First, eight adult females' adaptation to a new room in regulation-size cages was monitored, and in the third week their responses to ketamine sedation were measured. Then they spent two weeks singly housed in each of four cage sizes (USDA regulation size, one size larger, one size smaller, and a very small cage). Half of the subjects were in upper-level cages and the remainder in lower-level cages for the entire study. Cage size, ranging from 20% to 148% of USDA regulation floor area, was not significantly related to abnormal behavior, self-grooming, manipulating the environment, eating/drinking, activity cycle, cortisol excretion, or biscuit consumption. Locomotion and frequency of behavior change were significantly reduced in the smallest cage, but did not differ in cage sizes ranging from 77% to 148% of regulation size. The only manipulation to produce an unequivocal stress response, as measured by cortisol elevation and appetite suppression, was ketamine sedation. Room change and cage changes were associated with minimal cortisol elevation and appetite suppression. Wild-born females showed more appetite suppression after room change than captive-born females. No differences were related to cage level. Pigtailed macaques strongly resembled longtailed macaques except they showed weaker responses to the new room and cage change, probably because the pigtails had spent more time in captivity. These findings support the conclusion that increasing cage size to the next regulation size category would not have measurable positive effects on the psychological well-being of two species of laboratory macaques.

Differences in stress reactivity of laboratory macaques measured by heart period and respiratory sinus arrhythmia.

Some laboratory primates are more likely than others to react to anxiety-provoking stressors. Individuals that overreact to stressors may experience diminished psychological well-being and would be inappropriate for some experiments. The differences between reactive and nonreactive individuals may be reflected in heart period and respiratory sinus arrhythmia (RSA). Using surface electrodes and radio telemetry, we measured these two cardiac variables in seven male and ten female singly caged longtailed macaques (Macaca fascicularis) when they were exposed to two stressors, a sudden noise (whistle test) and an unfamiliar technician wearing capture gloves (glove test). Behavior was videotaped during both tests. For the whistle test, cardiac data were recorded before, during, and after two 1 minute whistle blasts separated by 90 min. For the glove test, data were recorded in 1 minute blocks every 8 minutes over 96 minutes before, during, and after 1 minute exposure to the gloved technician. Heart period was decreased and RSA was suppressed during both the whistle and glove exposures. After the whistle test, the cardiac activity of most subjects returned to baseline levels within 10 minutes. The glove test produced more extended suppression, with greater individual differences, than the whistle test. There were greater individual differences in RSA than in heart period. These enhanced individual differences were used to define stress reactors that differed from nonreactors in their cardiac data profiles. Of 16 subjects that completed the glove test, five were identified as reactors.