Abstract: Adult male elephants periodically show the phenomenon of musth, a condition associated with increased aggressiveness, restlessness, significant weight reduction and markedly elevated androgen levels. It has been suggested that musth-related behaviours are costly and that therefore musth may represent a form of physiological stress. In order to provide data on this largely unanswered question, the first aim of this study was to evaluate different assays for non-invasive assessment of adrenocortical function in the male African elephant by (i) characterizing the metabolism and excretion of [3H]cortisol (3H-C) and [14C]testosterone (14C-T) and (ii) using this information to evaluate the specificity of four antibodies for determination of excreted cortisol metabolites, particularly with respect to possible cross-reactions with androgen metabolites, and to assess their biological validity using an ACTH challenge test. Based on the methodology established, the second objective was to provide data on fecal cortisol metabolite concentrations in bulls during the musth and non-musth condition. 3H-C (1 mCi) and 14C-T (100 microCi) were injected simultaneously into a 16 year old male and all urine and feces collected for 30 and 86 h, respectively. The majority (82%) of cortisol metabolites was excreted into the urine, whereas testosterone metabolites were mainly (57%) excreted into the feces. Almost all radioactive metabolites recovered from urine were conjugated (86% 3H-C and 97% 14C-T). In contrast, 86% and >99% of the 3H-C and 14C-T metabolites recovered from feces consisted of unconjugated forms. HPLC separations indicated the presence of various metabolites of cortisol in both urine and feces, with cortisol being abundant in hydrolysed urine, but virtually absent in feces. Although all antibodies measured substantial amounts of immunoreactivity after HPLC separation of peak radioactive samples and detected an increase in glucocorticoid output following the ACTH challenge, only two (in feces against 3alpha,11-oxo-cortisol metabolites, measured by an 11-oxo-etiocholanolone-EIA and in urine against cortisol, measured by a cortisol-EIA) did not show substantial cross-reactivity with excreted 14C-T metabolites and could provide an acceptable degree of specificity for reliable assessment of glucocorticoid output from urine and feces. Based on these findings, concentrations of immunoreactive 3alpha,11-oxo-cortisol metabolites were determined in weekly fecal samples collected from four adult bulls over periods of 11-20 months to examine whether musth is associated with increased adrenal activity. Results showed that in each male levels of these cortisol metabolites were not elevated during periods of musth, suggesting that in the African elephant musth is generally not associated with marked elevations in glucocorticoid output. Given the complex nature of musth and the variety of factors that are likely to influence its manifestation, it is clear, however, that further studies, particularly on free-ranging animals, are needed before a possible relationship between musth and adrenal function can be resolved. This study also clearly illustrates the potential problems associated with cross-reacting metabolites of gonadal steroids in EIAs measuring glucocorticoid metabolites. This has to be taken into account when selecting assays and interpreting results of glucocorticoid metabolite analysis, not only for studies in the elephant but also in other species.

Abstract: Personality ratings of 196 cats were made by their owners using a 5-point Likert scale anchored by 1: not at all and 5: a great deal with 12 items: timid, friendly, curious, sociable, obedient, clever, protective, active, independent, aggressive, bad-tempered, and emotional. A principal components analysis with varimax rotation identified three intepretable components. Component I had high loadings by active, clever, curious, and sociable. Component II had high loadings by emotional, friendly, and protective, Component III by aggressive and bad-tempered, and Component IV by timid. Sex was not associated with any component, but age showed a weak negative correlation with Component I. Older animals were rated less social and curious than younger animals.

Abstract: Reports from different laboratories have suggested that nonhuman primates have somewhat similar dimensions of personality. To date, however, no attempts have been made to statistically replicate a specific factor structure. In the present report, two independent observers recorded the behavior of 58 adult male rhesus monkeys, and then rated the animals with the use of a 50-item personality instrument. A confirmatory factor analysis (CFA) of the ratings resulted in the replication of a previously described four-factor personality structure [Maninger et al., American Journal of Primatology 61:73-83, 2003]. The first two dimensions-Sociability and Confidence-showed strong loadings and are similar to Affiliation and Agency dimensions in humans. The remaining dimensions-Equability and Irritability-were less clear, and it is possible that additional traits will have to be identified before a more robust structure can be established for these dimensions.

Abstract: The idea that consistencies in behavior exist over time and across situations underlies human personality research. Although several studies have examined personality in nonhuman primates, there are very few data showing the predictive power of personality factors. The goal of the present study was to determine whether personality dimensions, identified in adult male rhesus monkeys living in half-acre cages, predicted behavior in situations different from the one from which the dimensions were originally derived and at time points of up to 4.5 years after the original assessments. Four personality dimensions (Sociability, Confidence, Excitability, and Equability) were identified using psychometric procedures and were correlated with behaviors recorded in several situations: the animals' natal groups, during tests of behavioral responsiveness while in individual cages, in small stable and unstable social groups, while viewing stimulus videotapes, and during stable social dyads. Results indicated substantial predictability. Sociability reflected a greater tendency to engage in affiliative interactions. Confidence correlated with more aggressive behaviors and with behaviors that suggest less attractiveness. Animals high in Excitability were somewhat inconsistent in their social behavior, perhaps reflecting hyper-responsiveness to novel circumstances and thwarted opportunities for escape. Equability appeared to be related to a less aggressive, more passive, style of interaction. Excitability and Equability appear to reflect more stylistic components of social behavior, whereas Sociability and Confidence may be more content-based dimensions. Sociability was strongly related to size of kin network in the animals' natal groups, suggesting an important role for ontogeny in this dimension. These data suggest that a limited number of personality dimensions exist in adult male rhesus macaques, and that these dimensions have predictive power that is both long-term and cross situational.