Abstract: Black-and-white snub-nosed monkeys (Rhinopithecus bieti) have almost never been the subject of any behavioural observations in captivity. This study was aimed at providing preliminary information about agonistic and reconciliation behaviour in a group kept at the Kunming Institute of Zoology in China. Established procedures were used for this investigation (i.e., the postconflict/matched-control method and the time-rule method). Intra-group aggression rates were quite low. Postconflict affiliation as well as selective attraction of former opponents to each other following conflicts was demonstrated. Former opponents contacted each other earlier in postconflict periods than in matched-control periods. The average conciliatory tendency of all focal individuals combined was 54.5%. After an agonistic interaction, the first affiliative contact between former aggressors usually took place within the first minute. The behaviours most often shown as first affiliations after a conflict were body contact, mount, touch, and “hold-lumbar”, of which the latter is an explicit reconciliatory gesture. Furthermore, the adult male intervened non-aggressively in 84% of all conflicts (n=25) among the adult females. Overall, the patterns of aggression and reconciliation observed in R. bieti bear many of the traits that characterise tolerant primate species.

Abstract: The current study represents the first systematic investigation of the social communication of captive siamangs (Symphalangus syndactylus). The focus was on intentional signals, including tactile and visual gestures, as well as facial expressions and actions. Fourteen individuals from different groups were observed and the signals used by individuals were recorded. Thirty-one different signals, consisting of 12 tactile gestures, 8 visual gestures, 7 actions, and 4 facial expressions, were observed, with tactile gestures and facial expressions appearing most frequently. The range of the signal repertoire increased steadily until the age of six, but declined afterwards in adults. The proportions of the different signal categories used within communicative interactions, in particular actions and facial expressions, also varied depending on age. Group differences could be traced back mainly to social factors or housing conditions. Differences in the repertoire of males and females were most obvious in the sexual context. Overall, most signals were used flexibly, with the majority performed in three or more social contexts and almost one-third of signals used in combination with other signals. Siamangs also adjusted their signals appropriately for the recipient, for example, using visual signals most often when the recipient was already attending (audience effects). These observations are discussed in the context of siamang ecology, social structure, and cognition.

Abstract: Non-invasive techniques to monitor stress hormones in small animals like mice offer several advantages and are highly demanded in laboratory as well as in field research. Since knowledge about the species-specific metabolism and excretion of glucocorticoids is essential to develop such a technique, we conducted radiometabolism studies in mice (Mus musculus f. domesticus, strain C57BL/6J). Each mouse was injected intraperitoneally with 740 kBq of 3H-labelled corticosterone and all voided urine and fecal samples were collected for five days. In a first experiment 16 animals (eight of each sex) received the injection at 9 a.m., while eight mice (four of each sex) were injected at 9 p.m. in a second experiment. In both experiments radioactive metabolites were recovered predominantly in the feces, although males excreted significantly higher proportions via the feces (about 73%) than females (about 53%). Peak radioactivity in the urine was detected within about 2h after injection, while in the feces peak concentrations were observed later (depending on the time of injection: about 10h postinjection in experiment 1 and about 4h postinjection in experiment 2, thus proving an effect of the time of day). The number and relative abundance of fecal [3H]corticosterone metabolites was determined by high performance liquid chromatography (HPLC). The HPLC separations revealed that corticosterone was extensively metabolized mainly to more polar substances. Regarding the types of metabolites formed, significant differences were found between males and females, but not between the experiments. Additionally, the immunoreactivity of these metabolites was assessed by screening the HPLC fractions with four enzyme immunoassays (EIA). However, only a newly established EIA for 5alpha-pregnane-3beta,11beta,21-triol-20-one (measuring corticosterone metabolites with a 5alpha-3beta,11beta-diol structure) detected several peaks of radioactive metabolites with high intensity in both sexes, while the other EIAs showed only minor immunoreactivity. Thus, our study for the first time provides substantial information about metabolism and excretion of corticosterone in urine and feces of mice and is the first demonstrating a significant impact of the animals' sex and the time of day. Based on these data it should be possible to monitor adrenocortical activity non-invasively in this species by measuring fecal corticosterone metabolites with the newly developed EIA. Since mice are extensively used in research world-wide, this could open new perspectives in various fields from ecology to behavioral endocrinology.

Abstract: In a number of mammalian species, males appear to have superior spatial abilities to females. The favoured explanations for this cognitive difference are hormonal, with higher testosterone levels in males than females leading to better spatial performance, and evolutionary, where sexual selection has favoured males with increased spatial abilities for either better navigational skills in hunting or to enable an increased territory size. However, an alternative explanation for this sex difference focuses on the role of varying levels of oestrogen in females in spatial cognition (the 'fertility and parental care' hypothesis). One possibility is that varying oestrogen levels result in variation in spatial learning and memory so that, when tested across the oestrous cycle, females perform as well as males on days of low oestrogen but more poorly on days of high oestrogen. If day in the oestrous cycle is not taken into account then, across an experiment, any sex differences found would always produce male superiority. We used a spatial working memory task in a Morris water maze to test the spatial learning and memory abilities of male and female rats. The rats were tested across a number of consecutive days during which the females went through four oestrous cycles. We found no overall sex differences in latencies to reach a submerged platform in a Morris water maze but, on the day of oestrus (low oestrogen), females took an extra swim to learn the platform's location (a 100% increase over the other days in the cycle). Female swim speed also varied across the oestrous cycle but females were no less active on the day of oestrus. These results oppose the predictions of the fertility and parental care hypothesis.