The dissection of a despotic society: exploration, dominance and hormonal traits.

Naked mole-rats (Heterocephalus glaber) live in large colonies with one breeding female (queen), one to three breeding males (BMs) and the remainder are non-reproductive subordinates. The animals have a linear dominance rank with the breeders at the top of the hierarchy. We investigated how dominance rank in naked mole-rats differs with exploration (the propensity to explore a novel environment) and related endocrine markers. Exploration behaviour, faecal progestagen metabolite (fPM), faecal glucocorticoid metabolite (fGCM), faecal androgen metabolite (fAM) and plasma prolactin concentrations were quantified in breeding, high-, middle- and low-ranked females and males from five naked mole-rat colonies. There were no significant differences between the dominance rank and exploration behaviour. Interestingly, the queens and high-ranking females had higher fGCM and fAM concentrations compared with middle- and low-ranked females. The queens had significantly higher fPM concentrations than all other ranked females, since they are responsible for procreation. In the males, the BMs had higher fGCM concentrations compared with high- and low-ranked males. In addition, BMs and middle-ranking males had overall higher prolactin levels than all other ranked males, which could be linked to cooperative care. Overall, the results suggest that physiological reproductive suppression is linked to high dominance rank.

A comprehensive profile of reproductive hormones in eusocial Damaraland mole-rats (Fukomys damarensis).

In species where sociality and group cohesion are primarily determined by the maintenance of a reproductive division of labour and cooperative behaviours, the eusocial Damaraland mole-rat (Fukomys damarensis) presents a model which provides behavioural and endocrine distinctions between sex (males and females) and reproductive class (breeders and non-breeders). Although previous studies have demonstrated the endocrine aspects of reproductive suppression and behaviour in Damaraland mole-rats, they have focused on one hormone separately and on different conspecifics and samples across time. Unfortunately, this could introduce extrinsic biases when using these studies to compile complete hormonal profiles for comparisons. This study, therefore, set out to obtain a profile of the reproductive hormones from breeding and non-breeding male and female Damaraland mole-rats at a single point in time, from which circulating plasma prolactin and urinary progesterone, testosterone, and cortisol were measured. As expected, plasma prolactin and urinary cortisol did not differ between the breeders and non-breeders. However, breeders (both male and female) possessed increased urinary testosterone and progesterone concentrations compared to their non-breeding counterparts. These results, in conjunction with the variation in the expression of the respective hormonal receptors within the brains of breeders and non-breeders suggest that elevated testosterone and progesterone in breeders establish a neural dominance phenotype, which ultimately aids in controlling breeding activities. This study has emphasised the need for holistic, comprehensive profiling of reproductive endocrine systems.

Patterns of faecal glucocorticoid metabolite levels in captive roan antelope (Hippotragus equinus) in relation to reproductive status and season.

Populations of roan antelope (Hippotragus equinus) in southern Africa have experienced a drastic decline over the past few decades and this situation has led to the development of intensive breeding programmes to support conservation efforts. However, little is known about related welfare aspects, including stress-related physiological biomarkers. The present study set out to establish a non-invasive method to monitor faecal glucocorticoid metabolite (fGCM) concentrations as a measure of stress and determine fGCM concentrations in relation to male reproductive activity and female reproductive status in the roan antelope. An adrenocorticotrophic hormone challenge was performed using two adult roan antelope (one male and one female) at Lapalala Wilderness Nature Reserve, South Africa, to determine the suitability of five enzyme immunoassays (EIA) for monitoring adrenocortical function in roan antelope. An 11-oxoaetiocholanolone I EIA detecting 11,17 dioxoandrostanes performed best showing 17-20 folds increases in fGCM concentrations after 12 h-17 h post-injection. The identified EIA was then used to monitor fGCM concentrations during active and non-active reproductive periods in males (n = 3), and during periods of cyclicity, gestation, and postpartum in females (n = 10). Males showed an overall 80% increase in fGCM concentrations when reproductively active and females showed a progressively significant increase in fGCM levels throughout pregnancy, with overall fGCM concentrations being 1.5 to 2.6-fold higher than the respective fGCM concentrations during periods of postpartum and cyclicity, respectively. Furthermore, fGCM concentrations remained above baseline for up to 21 days post-partum. A correlation between ecological parameters (rainfall and temperature) and fGCM concentrations revealed elevated fGCM concentrations during the dry season for males, but not females. The non-invasive method validated in this study provides a valuable tool to quantify stress-related biomarkers in roan antelope, and findings can be used to support management decisions in conservation breeding facilities.

Hot days are associated with short-term adrenocortical responses in a southern African arid-zone passerine bird.

Relatively little effort has been directed towards elucidating the role of physiological stress pathways in mediating avian responses to global heating. For free-ranging southern pied babblers, Turdoides bicolor, daily maximum air temperatures (Tmax) between ∼35 and ∼40°C result in reduced foraging efficiency, loss of body mass and compromised breeding success. We tested the hypothesis that very hot days are experienced as stressors by quantifying relationships between Tmax and faecal glucocorticoid metabolite (fGCM) levels in naturally excreted droppings. On days when Tmax<38°C, fGCM levels were independent of Tmax (mean±s.d. 140.25±56.92 ng g-1 dry mass). At Tmax>38°C, however, fGCM levels increased linearly with Tmax and averaged 190.79±70.13 ng g-1 dry mass. The effects of Tmax on fGCM levels did not carry over to the following morning, suggesting that very hot days are experienced as acute stressors.

Behavioural change during dispersal and its relationship to survival and reproduction in a cooperative breeder.

The ability of dispersing individuals to adjust their behaviour to changing conditions is instrumental in overcoming challenges and reducing dispersal costs, consequently increasing overall dispersal success. Understanding how dispersers' behaviour and physiology change during the dispersal process, and how they differ from resident individuals, can shed light on the mechanisms by which dispersers increase survival and maximise reproduction. By analysing individual behaviour and concentrations of faecal glucocorticoid metabolites (fGCM), a stress-associated biomarker, we sought to identify the proximate causes behind differences in survival and reproduction between dispersing and resident meerkats Suricata suricatta. We used data collected on 67 dispersing and 108 resident females to investigate (a) which individual, social and environmental factors are correlated to foraging and vigilance, and whether the role of such factors differs among dispersal phases, and between dispersers and residents; (b) how time allocated to either foraging or vigilance correlated to survival in dispersers and residents and (c) the link between aggression and change in fGCM concentration, and their relationship with reproductive rates in dispersing groups and resident groups with either long-established or newly established dominant females. Time allocated to foraging increased across dispersal phases, whereas time allocated to vigilance decreased. Time allocated to foraging and vigilance correlated positively and negatively, respectively, with dispersers' group size. We did not find a group size effect for residents. High proportions of time allocated to foraging correlated with high survival, and more so in dispersers, suggesting that maintaining good physical condition may reduce mortality during dispersal. Furthermore, while subordinate individuals rarely reproduced in resident groups, the conception rate of subordinates in newly formed dispersing groups was equal to that of their dominant individuals. Mirroring conception rates, in resident groups, fGCM concentrations were lower in subordinates than in dominants, whereas in disperser groups, fGCM concentrations did not differ between subordinates and dominants. Our results, which highlight the relationship between behavioural and physiological factors and demographic rates, provide insights into some of the mechanisms that individuals of a cooperative species can use to increase overall dispersal success.

Scales of our lives: Sex identification of Temminck's pangolin (Smutsia temminckii) using scales retrieved out of the illegal wildlife trade.

Pangolins are the most trafficked wild mammals, with their scales in high demand. Scales are often the only part of the animal confiscated from the trade, but they represent accessible material for forensic investigations, including for sexing. This study aimed to develop a sexing tool for Temminck's pangolin, using scales for hormone quantification. Scales from males and females were liquidised using keratinase and the resulting suspension analysed for progestagen and androgen metabolite (scPM and scAM) concentrations. Scale PM and scAM concentrations were compared between sexes, while overall median values for scPM and scAM, as well as a ratio of scPM to scAM (P/A) were used as boundary values for sex identification. Neither scPM nor scAM concentrations were significantly different between the sexes and concentrations of a juvenile and sub-adult male overlapped with females, possibly indicating later sexual maturity in males. Boundary values for scAM concentrations and the P/A ratio predicted sex with 100% accuracy for females and 78% for males, while the accuracies for the scPM boundary value were lower. When only adult individuals are considered, scAM and P/A ratio boundaries are 100% accurate for both sexes. Therefore, scale hormone ratios show promise as a sex identification tool for Temminck's pangolin, particularly applicable in forensic investigations on the pangolin trade.

Non-invasive monitoring of glucocorticoid metabolite concentrations in native Indian, as well as captive and re-wilded tigers in South Africa.

Over the last century, wild tiger (Panthera tigris) numbers have declined from over 100 000 individuals to fewer than 4 000, with animals now confined to less than 5% of their historic range due to habitat loss, persecution, inadequate management, and poaching. In contrast, 15 000-20 000 tigers are estimated to be housed in captivity, experiencing conditions vastly different than their wild counterparts. A total of 280 tigers are currently held at 44 different facilities within South Africa, including zoos, semi-captive 're-wilded' populations, and pets; these animals provide a unique opportunity to measure the impact of extrinsic factors, found in exotic habitats, on the adrenocortical activity of tigers. By monitoring and comparing stress-related faecal glucocorticoid metabolite (fGCM) concentrations of tigers housed at different locations, and free ranging tigers in natural tiger reserves, this project aimed to get a better understanding of the impact of extrinsic factors on adrenocortical function as a measure of stress. The results of this study showed no significant difference in fGCM concentrations between captive, re-wilded, and free-ranging tigers with the exception of one site. Furthermore, factors such as sex and season were not significant drivers of fGCM concentrations. One study group had elevated fGCM concentrations, showing population variation in the stress response. This indicates that populations are able to cope with exotic environments, however, as population-specific differences in the stress response exist, we suggest management protocols be created for each population. This study offered the unique opportunity to see how well tigers are faring outside of their native range and if having re-wilded tigers in exotic locations is a potential welfare-acceptable management option for tiger conservation globally.

Repeatability of daily profiles of baseline glucocorticoid metabolites measured in the urine and faeces of eastern rock sengis (Elephantulus myurus).

Repeatability of hormone concentrations is of great interest for studies investigating the evolution of hormonal traits. Particularly the repeatability of glucocorticoids (GCs) in response to a stressor is frequently investigated, but often only point (initial and/or response value), or single measures are used. A new method takes into account the entire individual hormone profile and generates an individual profile repeatability (PR) score. The method was developed for response profiles, but it may also be valuable for baseline values in species with diurnal changes in hormone concentrations. GCs are determined in a variety of matrices, and repeatability can vary considerably depending on the matrix. We investigated the repeatability of baseline GC metabolite (GCM) concentrations measured in urine (uGCM) and faeces (fGCM) of captive eastern rock sengis (Elephantulus myurus) using the more traditional linear mixed model approach and the PR method. GCMs were assessed over 24 h and measurements were repeated twice with two weeks between replicates. A diurnal rhythm in GCM concentrations associated with the activity period of the sengis was found in urine, but not in the faeces. Urinary GCM concentrations exhibited a moderate repeatability, whereas the repeatability of fGCM concentrations was low. Urinary GCM concentrations and their repeatability differed between the sexes; with higher concentrations and lower PR scores in females. No such sex differences were apparent for fGCM concentrations and the PR score was not able to characterise repeatability of fGCM concentrations, which were lacking a distinct profile. The PR score enabled a successful quantification of the repeatability of the diurnal uGCM profiles. Hormone profile, sex and sample matrix can affect hormonal traits considerably and the results may be obscured if these factors are not carefully considered.

Decadal shift in foraging strategy of a migratory southern ocean predator.

Rapid anthropogenic environmental change is expected to impact a host of ecological parameters in Southern Ocean ecosystems. Of critical concern are the consequences of these changes on the range of species that show fidelity to migratory destinations, as philopatry is hypothesized to help or hinder adaptation to climate change depending on the circumstances. Many baleen whales show philopatry to feeding grounds and are also capital breeders that meet migratory and reproductive costs through seasonal energy intake. Southern right whales (Eubalaena australis, SRWs) are capital breeders that have a strong relationship between reproductive output and foraging success. The population dynamics of South Africa's population of SRWs are characterized by two distinct periods: the 1990s, a period of high calving rates; and the late 2010s, a period associated with lowered calving rates. Here we use analyses of stable carbon (δ13 C) and nitrogen (δ15 N) isotope values from SRW biopsy samples (n = 122) collected during these two distinct periods to investigate foraging ecology of the South African population of SRWs over a time period coincident with the demographic shift. We show that South African SRWs underwent a dramatic northward shift, and diversification, in foraging strategy from 1990s to 2010s. Bayesian mixing model results suggest that during the 1990s, South African SRWs foraged on prey isotopically similar to South Georgia/Islas Georgias del Sur krill. In contrast, in the 2010s, South African SRWs foraged on prey isotopically consistent with the waters of the Subtropical Convergence, Polar Front and Marion Island. We hypothesize that this shift represents a response to changes in preferred habitat or prey, for example, the decrease in abundance and southward range contraction of Antarctic krill. By linking reproductive decline to changing foraging strategies for the first time in SRWs, we show that altering foraging strategies may not be sufficient to adapt to a changing ocean.

Effect of colony disruption and social isolation on naked mole-rat endocrine correlates.

The social environment of animals can have profound implications on their behaviour and physiology. Naked mole-rats (Heterocephalus glaber) are highly social with complex dominance hierarchies that influence both stress- and reproduction-related hormones. Homeostasis may be affected by aggressive interactions, colony instability and social isolation. Furthermore, naked mole-rat colonies are characterised by a marked reproductive skew; a single female and few males are reproductively active while other colony members are reproductively suppressed. Thus, there are distinct differences in related hormone concentrations between reproductively active and non-active animals; however, this changes when non-reproductive individuals are removed from the colony. We investigated the effects of social isolation and colony disruption on plasma cortisol and progesterone concentrations in non-breeding naked mole-rats. During colony disruption, we found a significant increase in cortisol concentrations in females removed from the colony for social isolation (experimental) as well as in females that remained in the colony (control). Cortisol concentrations were reduced in both groups after experimental animals were paired up. No changes in cortisol concentrations were observed in control or experimental males after removal from the colony or pairing. This suggests that the females, but not the males, found colony disruption and social isolation stressful. Upon removal from the colony, both control and experimental females showed a small increase in progesterone, which returned to basal levels again in the control animals. Experimental females showed a dramatic spike in progesterone when they were paired with males, indicating reproductive activation. The sex difference in the stress responses may be due to the stronger reproductive suppression imposed on females, or the increased likelihood of dispersal for males. It is clear that the social environment reflects on the endocrine correlates of animals living in a colony, and that the colony structure may affect the sensitivity of the animals to changes in their environment.

Effect of food limitation and reproductive activity on fecal glucocorticoid metabolite levels in banded mongooses.

BACKGROUND: Glucocorticoids mediate responses to perceived stressors, thereby restoring homeostasis. However, prolonged glucocorticoid elevation may cause homeostatic overload. Using extensive field investigations of banded mongoose (Mungos mungo) groups in northern Botswana, we assessed the influence of reproduction, predation risk, and food limitation on apparent homeostatic overload (n=13 groups, 1542 samples from 268 animals). We experimentally manipulated reproduction and regulated food supply in captive mongooses, and compared their glucocorticoid responses to those obtained from free-living groups. RESULTS: At the population level, variation in glucocorticoid levels in free-living mongooses was explained by food limitation: fecal organic matter, recent rainfall, and access to concentrated anthropogenic food resources. Soil macrofauna density and reproductive events explained less and predation risk very little variation in glucocorticoid levels. Reproduction and its associated challenges alone (under regulated feeding conditions) increased glucocorticoid levels 19-fold in a captive group. Among free-living groups, glucocorticoid elevation was seasonal (occurring in late dry season or early wet season when natural food resources were less available), but the timing of peak glucocorticoid production was moderated by access to anthropogenic resources (groups with fewer anthropogenic food sources had peaks earlier in dry seasons). Peak months represented 12- and 16-fold increases in glucocorticoids relative to nadir months with some animals exhibiting 100-fold increases. Relative to the captive group nadir, some free-living groups exhibited 60-fold increases in peak glucocorticoid levels with some animals exhibiting up to 800-fold increases. Most of these animals exhibited 1- to 10-fold increases relative to the captive animal peak. CONCLUSIONS: Banded mongooses exhibit seasonal chronic glucocorticoid elevation, associated primarily with food limitation and secondarily with reproduction. Magnitude and duration of this elevation suggests that this may be maladaptive for some animals, with possible fitness consequences. In late dry season, this population may face a convergence of stressors (food limitation, agonistic encounters at concentrated food resources, evictions, estrus, mate competition, parturition, and predation pressure on pups), which may induce homeostatic overload.

Sex and dose-dependent responses of urinary and faecal glucocorticoid metabolite concentrations following an ACTH challenge in eastern rock sengis (Elephantulus myurus).

Non-invasive methods for measuring glucocorticoids and their metabolites are frequently used in ecological, behavioural and physiological studies of mammals. Using faeces, urine and other matrices for such a measurement has considerable advantages in comparison to more traditional methods, but also requires thorough validation of the methods used. Eastern rock sengis (Elephantulus myurus) are fascinating African mammals and the non-invasive monitoring of the adrenocortical activity opens up new opportunities to study their biology. We were able to validate two assays for measuring urinary (uGCM) and faecal glucocorticoid metabolite (fGCM) concentrations in this species using a dose-dependent challenge with adrenocorticotropic hormone (ACTH). A higher concentration of ACTH elicited higher uGCM and fGCM concentrations in both males and females. Interestingly, uGCM and fGCM concentrations and the responses to ACTH were higher in females than in males and small changes in faecal glucocorticoid metabolites could not be reliably detected in males. In contrast to ACTH, a saline injection did not result in an increase in uGCM or fGCM concentrations. The study also provided insight into when responses to a stressor are likely to be detected in the urine and faeces of sengis and opens up new opportunities to study the stress physiology of this and other sengi species. It further emphasises the importance of thoroughly validating non-invasive methods for measuring hormones in both sexes of a species and for incorporating dose-dependent approaches.

Cost of dispersal in a social mammal: body mass loss and increased stress.

Dispersal is a key process influencing the dynamics of socially and spatially structured populations. Dispersal success is determined by the state of individuals at emigration and the costs incurred after emigration. However, quantification of such costs is often difficult, due to logistical constraints of following wide-ranging individuals. We investigated the effects of dispersal on individual body mass and stress hormone levels in a cooperative breeder, the meerkat ( Suricata suricatta). We measured body mass and faecal glucocorticoid metabolite (fGCM) concentrations from 95 dispersing females in 65 coalitions through the entire dispersal process. Females that successfully settled lost body mass, while females that did not settle but returned to their natal group after a short period of time did not. Furthermore, dispersing females had higher fGCM levels than resident females, and this was especially pronounced during the later stages of dispersal. By adding information on the transient stage of dispersal and by comparing dispersers that successfully settled to dispersers that returned to their natal group, we expand on previous studies focusing on the earlier stages of dispersal. We propose that body mass and stress hormone levels are good indicators to investigate dispersal costs, as these traits often play an important role in mediating the effects of the environment on other life-history events and individual fitness.

Changes in prolactin, cortisol and testosterone concentrations during queen succession in a colony of naked mole-rats (Heterocephalus glaber): a case study.

Colonies of naked mole-rats (Heterocephalus glaber, NMRs) are characterised by an extreme skew in lifetime reproductive success with only one female and one to three male consorts in a colony. The rest of the individuals in a colony are reproductively suppressed and much research has been focussed on elucidating that mechanism. The dopamine system and prolactin have recently been implicated in the suppression of reproduction of subordinate NMRs. To investigate the changes in prolactin during the removal of an aged reproductive female (queen) and succession of a new queen, blood samples were collected during different stages of queen removal: before queen removal, after separation, but in olfactory contact with the queen and after the total removal of the queen. Further, plasma cortisol and testosterone concentrations were determined. The colony appeared unstable prior to queen removal as indicated by high concentrations of cortisol and testosterone and lack of successful breeding. A new queen succeeded the old queen whilst she was still in olfactory contact. The time preceding queen succession was characterised by high levels of aggression, the death of a number of individuals, high cortisol and testosterone and low prolactin concentrations. Once the older queen was removed entirely and the new queen had given birth, prolactin concentrations increased and cortisol and testosterone concentrations decreased in subordinate NMRs. The results suggest that low prolactin levels are associated with low reproductive suppression during times of colony instability due to the removal or death of a queen.

Social rank does not affect sperm quality in male African wild dogs (Lycaon pictus).

Sperm banking and AI could benefit endangered African wild dog conservation. However, it is unclear whether their dominance hierarchy causes a decrease in reproductive and sperm quality parameters in subordinate males that typically do not breed. In this study, we investigated the effect of social rank on male reproductive parameters, including faecal androgen and glucocorticoid metabolite concentrations, prostate and testes volume, preputial gland size, semen collection success and sperm quality. Samples were obtained from captive males (prebreeding season: n=12 from four packs; breeding season: n=24 from seven packs) that were classified as alpha (dominant), beta or gamma (subordinates) based on the frequency of dominant versus submissive behaviours. In the prebreeding season, semen was successfully collected from all alpha but only half the subordinate males, with urine contamination (associated with lower rank) significantly reducing total and progressive motility, sperm motility index, normal sperm morphology and acrosome integrity. The breeding season was associated with a significant increase in faecal androgens, prostate and testis volume, as well as progressive motility and the total number of spermatozoa ejaculated. However, with the exception of prostate volume (mean±s.e.m: 12.5±4.5, 7.1±1.0 and 7.3±1.0cm3 in alpha, beta and gamma males respectively; P=0.035), all other reproductive and sperm quality parameters did not differ between males of each social rank. In conclusion, reproductive suppression of subordinate males appears to be behaviourally mediated, because males of all social ranks produce semen of similar quality, making them suitable candidates for sperm banking, particularly during the breeding season when sperm quality improves.

Non-invasive monitoring of physiological stress in an afrotropical arid-zone passerine bird, the southern pied babbler.

Using faecal matter to monitor stress levels in animals non-invasively is a powerful technique for elucidating the effects of biotic and abiotic stressors on free-living animals. To validate the use of droppings for measuring stress in southern pied babblers (Turdoides bicolor) we performed an ACTH challenge on captive individuals and determined the effect of temporary separation from their social group on their faecal glucocorticoid metabolite (fGCM) concentration. Additionally, we compared fGCM concentrations of captive babblers to those of wild conspecifics and examined the effects of dominance rank on fGCM concentration. We found droppings to be a suitable matrix for measuring physiological stress in babblers and that individual separation from the group caused an increase in fGCM levels. In addition, babblers temporarily held in captivity had substantially higher fGCM concentrations than wild individuals, indicating that babblers kept in captivity experience high levels of stress. In wild, free-living individuals, dominant males showed the highest levels of stress, suggesting that being the dominant male of a highly territorial social group is stressful. Non-invasive sampling allows field-based researchers to reduce disturbance related to monitoring adrenocortical function, thereby avoiding artificially increasing circulating corticosterone concentration as it is not necessary to physically restrain study animals.

Noninvasive measurements of ovarian activity in Beira antelope (Dorcatragus megalotis).

As the natural habitat of more and more species becomes depleted, captive breeding programmes have become established to bring species back from the brink of extinction. Monitoring the reproductive status of an individual is essential in order to improve breeding success. Traditional methods have involved stressful blood sampling, and thus noninvasive methods have been proven to be reliable alternatives for monitoring reproductive function in both captive and free-ranging animals. Subsequently, noninvasive methods have become an invaluable tool in longitudinal studies and conservation efforts, as animals can be observed without, or minimal human contact. The Beira antelope is a small antelope endemic to the northern part of the Horn of Africa. Population numbers of the Beira have been declining over the last few decades due to habitat fragmentation. We show here that the reproductive cycle of female Beira antelopes can be monitored noninvasively, by using faecal samples to analyse oestrogen (fEM) as well as progestagen (fPM) metabolites. The profiles of fPM and fEM of both females showed regular cyclic patterns in which the follicular and luteal phases could be distinguished. The overall mean cycle length is 22 days (range: 21-25 days), with a mean length of the follicular phase of 6 days (range: 4-7 days) and a mean length for the luteal phase being 15 days (range: 12-16 days). The suitability of these noninvasive techniques should assist in optimizing breeding efforts of this endemic small antelope in captivity. Being noninvasive, this method could also be a useful tool for monitoring reproductive function in the dwindling wild populations.

Non-invasive assessment of glucocorticoid and androgen metabolite levels in cooperatively breeding Damaraland mole-rats (Fukomys damarensis).

Dominant females of cooperative breeding species often use aggression to suppress reproduction of subordinate females, resulting in subordinates experiencing stress-related increases in glucocorticoid levels, which may cause reproductive down-regulation. This would suggest a general pattern with higher glucocorticoid levels in subordinate compared to dominant individuals; however, the opposite was found in a number of cooperatively breeding species. Furthermore, breeding females of the cooperatively breeding Damaraland mole-rats (Fukomys damarensis) exhibit very high androgen concentrations during the wet season, presumably to support their breeding monopoly. Hormone analysis in Damaraland mole-rats have typically been measured using plasma and urine, but faecal analysis offers additional advantages especially for field studies on this species. The present study examines the suitability of Damaraland mole-rat faecal samples for determining glucocorticoid metabolite (fGCM) and androgen metabolite (fAM) concentrations using enzyme immunoassays. Using these assays, we further evaluated the effects of breeding status on fGCM and fAM concentrations in wild-caught and captive Damaraland mole-rats. Wild-caught breeding and non-breeding males and females exhibited no differences in fAM concentrations. Immunoreactive fGCM concentrations were only high in male breeders and comparatively low in non-breeders and breeding females. Concentrations of fAMs and fGCMs were similar in captive males and females, but fAM concentrations were elevated in captive compared to wild-caught individuals, which may be related to a higher reproductive activity due to removal from the breeding female. The relatively uniform fAM and fGCM concentrations found in wild-caught mole-rats may be explained by a stable colony structure during the dry season during which this study was conducted. Limited dispersal opportunities result in lower aggression and stress levels within a colony and as a result lower fAM and fGCM concentrations.

Detection of Simonsiella spp. in the Vagina of Lions and Leopard in Oestrus.

Reports of the vaginal flora of wild cats such as lions or leopards are scarce. The micro-organisms most commonly found in the vagina of clinically healthy cats are aerobic bacteria such as coagulase-negative Staphylococcus, Streptococcus canis, and Escherichia coli. Simonsiella spp are large Gram-negative bacteria belonging to the Neisseriaceae family, typically found in the oral cavity and upper respiratory tract of many species. To date, there are no reports of the detection of Simonsiella spp in the vaginal flora of any felid. For a period of six months, daily behaviour monitoring was performed on six captive lionesses at a South African conservation centre, in parallel with the collection of vaginal swabs and interpretation of the resultant vaginal cytologies every other day. Oestrus was identified by typical female reproductive behaviours, as well as by enlarged and separated vulvar lips, and a predominant proportion of superficial cornified cells, clearing of the background, and high bacterial presence in the vaginal smear. Simonsiella spp were identified by their characteristic morphology in 58% (60 of 103) of the vaginal samples collected during oestrus. They were also found in oral swabs of three out of three lions tested. Additionally, Simonsiella spp were opportunistically found in a vaginal smear from a zoo housed female Sri Lankan leopard in oestrus, during a routine reproduction assessment. The finding of Simonsiella spp may be more common than previously suspected, transitory, and without detectable clinical relevance. A connection between occurrence of these bacteria and oestrus was apparent.

The influence of stress hormones and aggression on cooperative behaviour in subordinate meerkats.

In cooperative breeders, aggression from dominant breeders directed at subordinates may raise subordinate stress hormone (glucocorticoid) concentrations. This may benefit dominants by suppressing subordinate reproduction but it is uncertain whether aggression from dominants can elevate subordinate cooperative behaviour, or how resulting changes in subordinate glucocorticoid concentrations affect their cooperative behaviour. We show here that the effects of manipulating glucocorticoid concentrations in wild meerkats (Suricata suricatta) on cooperative behaviour varied between cooperative activities as well as between the sexes. Subordinates of both sexes treated with a glucocorticoid receptor antagonist (mifepristone) exhibited significantly more pup protection behaviour (babysitting) compared to those treated with glucocorticoids (cortisol) or controls. Females treated with mifepristone had a higher probability of exhibiting pup food provisioning (pup-feeding) compared to those treated with cortisol. In males, there were no treatment effects on the probability of pup-feeding, but those treated with cortisol gave a higher proportion of the food they found to pups than those treated with mifepristone. Using 19 years of behavioural data, we also show that dominant females did not increase the frequency with which they directed aggression at subordinates at times when the need for assistance was highest. Our results suggest that it is unlikely that dominant females manipulate the cooperative behaviour of subordinates through the effects of aggression on their glucocorticoid levels and that the function of aggression directed at subordinates is probably to reduce the probability they will breed.