Abstract: The capercaillie (Tetrao urogallus), the largest grouse species in the world, is decreasing in numbers in major parts of its distribution range. Disturbances by human outdoor activities are discussed as a possible reason for this population decline. An indicator for disturbances is the increase of the glucocorticoid corticosterone, a stress hormone, which helps to cope with life-threatening situations. However, repeated disturbances might result in a long-term increase of the basal corticosterone concentration, which can result in detrimental effects like reduced fitness and survival of an animal. To measure corticosterone metabolites (CMs) noninvasively in the droppings of free-living capercaillies, first an enzyme immunoassay (EIA) in captive birds had to be selected and validated. Therefore, the excretion pattern of intravenously injected radiolabeled corticosterone was determined and 3H metabolites were characterized. High-performance liquid chromatography (HPLC) separations of the samples containing peak concentrations revealed that corticosterone was extensively metabolized. The HPLC fractions were tested in several EIAs for glucocorticoid metabolites. The physiological relevance of this method was proved after pharmacological stimulation of the adrenocortical activity. Only the recently established cortisone assay, measuring CMs with a 3,11-dione structure, detected an expressed increase of concentrations following ACTH stimulation. To set up a sampling protocol suited for the field, we examined the influence of various storage conditions and time of day on concentrations of CMs.

Abstract: During the past 20 years, measuring steroid hormone metabolites in fecal samples has become a widely appreciated technique, because it has proved to be a powerful, noninvasive tool that provides important information about an animal's endocrine status (adrenocortical activity and reproductive status). However, although sampling is relatively easy to perform and free of feedback, a careful consideration of various factors is necessary to achieve proper results that lead to sound conclusions. This article aims to provide guidelines for an adequate application of these techniques. It is meant as a checklist that addresses the main topics of concern, such as sample collection and storage, time delay extraction procedures, assay selection and validation, biological relevance, and some confounding factors. These issues are discussed briefly here and in more detail in other recent articles.

Abstract: A multitude of endocrine mechanisms are involved in coping with challenges. Front-line hormones to overcome stressful situations are glucocorticoids (GCs) and catecholamines (CAs). These hormones are usually determined in plasma samples as parameters of adrenal activity and thus of disturbance. GCs (and CAs) are extensively metabolized and excreted afterwards. Therefore, the concentration of GCs (or their metabolites) can be measured in various body fluids or excreta. Above all, fecal samples offer the advantages of easy collection and a feedback-free sampling procedure. However, large differences exist among species regarding the route and time course of excretion, as well as the types of metabolites formed. Based on information gained from radiometabolism studies (reviewed in this paper), we recently developed and successfully validated different enzyme immunoassays that enable the noninvasive measurement of groups of cortisol or corticosterone metabolites in animal feces. The determination of these metabolites in fecal samples can be used as a powerful tool to monitor GC production in various species of domestic, wildlife, and laboratory animals.

Abstract: Although many Malagasy lemurs are thought to be female dominant and to have female feeding priority, to date the relationship between these behaviors has been rigorously established only in Lemur catta, and other ways that females might achieve feeding priority have not been examined closely. Erhart and Overdorff [International Journal of Primatology 20:927-940, 1999] suggested that one way female primates achieve feeding priority is to initiate and lead groups to food, thereby gaining access to the food first and positively influencing their food intake compared to other group members. Here we describe female dominance patterns and potential measures of feeding priority in two groups of black-and-white ruffed lemurs (Varecia variegata) that were observed over a 15-month period in southeastern Madagascar. We predicted that the females would 1) be consistently dominant to males, 2) lead groups to food sources more often than males, and 3) have higher feeding rates compared to males when they arrived at food sources first. The results were dissimilar between the study groups. During the study, the oldest adult female in group 1 died. There was no evidence for female dominance in this group, and the remaining (likely natal) female did not lead the group more often, nor did she have a higher food intake than males. Group 1 dispersed shortly after the time frame reported here. In contrast, the resident female in group 2 was dominant to group males (based on agonistic interactions), led the group to food sources more often, and experienced a higher food intake when she arrived first at a food source. How these patterns vary over time and are influenced by the number of females in groups, group stability, food quality, and reproductive condition will be examined in future analyses.

Abstract: In recent years there has been a marked increase in awareness of issues involving the psychological well-being of nonhuman primates (NHPs) used in biomedical research. As a result, many facilities are starting to train primates to voluntarily cooperate with veterinary, husbandry, and research procedures, such as remaining still for blood draws or injections. Such training generally reduces the stress associated with these procedures, resulting in calmer animals and, ultimately, better research models. However, such training requires great investments in time, and there can be vast individual differences in training success. Some animals learn tasks quickly, while others make slower progress in training. In this study, we examined whether temperament, as measured by response to a novel food object, correlated with the amount of time it took to train 20 adult female rhesus macaques to perform a simple task. The monkeys were categorized as “exploratory” (i.e., inspected a novel object placed in the home cage within 10 sec), “moderate” (i.e., inspected the object within 10-180 sec), or “inhibited” (i.e., did not inspect the object within 3 min). We utilized positive reinforcement techniques to train the monkeys to touch a target (PVC pipe shaped like an elbow) hung on their cage. Temperament correlated with training success in this study (Pearson chi2=7.22, df=2, P=0.03). We easily trained over 75% of the animals that inspected the novel food (i.e., exploratory or moderate individuals) to touch the target. However, only 22% of the inhibited monkeys performed the task. By knowing which animals may not respond to conventional training methods, we may be able to develop alternate training techniques to address their specific needs. In addition, these results will allow us to screen monkeys to be assigned to research projects in which they will be trained, with the goal of obtaining the best candidates for those studies.