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.

Feasibility of a Sprague???Dawley Rat Model for Investigating the Effects of Seated Whole-body Vibration.

Vehicular whole-body vibration (WBV) can have long-term adverse effects on human quality of life. Animal models can be used to study pathophysiologic effects of vibration. The goal of this study was to assess animal cooperation and well-being to determine the feasibility of a novel seated rat model for investigating the effects of WBV on biologic systems. Twenty-four male Sprague???Dawley rats were used. The experiment consisted of an acclimation phase, 2 training phases (TrP1 and TrP2), and a testing phase (TeP), including weekly radiographic imaging. During acclimation, rats were housed in pairs in standard cages without vibration. First, experimental (EG; n = 18) and control group 1 (C1; n = 3) rats were placed in a vibration apparatus without vibration, with increasing duration over 5 d during TrP1. EG rats were exposed to vertical random WBV that was increased in magnitude over 5 d during TrP2 until reaching the vibration signal used during TeP (15min, 0.7m??s-2 root mean square, unweighted). C1 rats were placed in the vibration apparatus but received no vibration during any phase. Control group 2 (C2; n = 3) rats remained in the home cages. Cooperation was evaluated with regard to rat-apparatus interactions and position compliance. Behavior, weight, and fecal glucocorticoid metabolite concentrations (fGCM) were used to evaluate animal well-being. We observed good cooperation and no behavioral patterns or weight loss between phases, indicating little or no animal stress. The differences in fGCM concentration between groups indicated that the EG rats had lower stress levels than the control rats in all phases except TrP1. Thus, this model elicited little or no stress in the conscious, unrestrained, seated rats.

Identifying potential measures of stress and disturbance during a captive to wild African elephant reintegration.

There is increasing evidence of compromised welfare for elephants managed in captivity. Should such facilities eventually close, more elephants will need to be rehabilitated and reintegrated into the wild. The goal of such reintegration would be to restore any physical or psychological aspects of the elephant that may have been compromised in captivity, followed by introduction into a free-roaming system where they can interact with other elephants. However, to achieve this goal, the reintegration methods implemented need to be assessed to ensure that welfare remains the priority. The objective of this study was to test whether parameters generally associated with stress and disturbance in African elephants, respond to changes in potentially stressful environmental conditions, assessed at multiple temporal scales ranging from minutes to months. The main changes in environmental conditions that were investigated included the different phases of reintegration of a group of elephants from captivity into the wild. Stress and disturbance related parameters used for comparisons included physiological responses, namely the extent of temporal gland secretions (eTGS) and faecal glucocorticoid metabolite (fGCM) levels as well as behavioural responses, namely the display of stereotype and stress-related behaviours. Results showed that eTGS significantly increased during the initial release of the elephants compared to when in captivity. Stereotypic behaviours were only recorded during the captive phase and immediately ceased after release. Faecal GCM levels spiked in the first year after release before decreasing back to pre-reintegration levels during the third year. These findings indicate that fGCM levels, the eTGS and disturbance related behaviours all proved effective in explaining the changes in stress and disturbance experienced by elephants during the initial years after being reintegrated from captivity into the wild.

Non-Invasive Quantification of Faecal and Urine Reproductive Hormone Metabolites in the Naked Mole-Rat (Heterocephalus glaber).

The naked mole-rat (Heterocephalus glaber) occurs in colonies with a distinct dominance hierarchy, including one dominant, breeding female (the queen), 1-3 breeding males, and non-reproductive subordinates of both sexes that are reproductively suppressed while in the colony. To non-invasively evaluate reproductive capacity in the species, we first had to examine the suitability of enzyme immunoassays (EIAs) for determining progestogen and androgen metabolite concentrations in the naked mole-rat, using urine and faeces. A saline control and gonadotrophin-releasing hormone (GnRH) were administered to twelve (six males and six females) naked mole-rats which were previously identified as dispersers and housed singly. The results revealed that urine is possibly not an ideal matrix for progestogen and androgen metabolite quantification in naked mole-rats as no signal was detected in the matrix post GnRH administration. A 5α-Progesterone EIA and an Epiandrosterone EIA were identified as suitable for quantifying faecal progesterone metabolites (fPMs) and faecal androgen metabolites (fAMs) in males and females, respectively. The results suggest that there are individual variations in baseline fPM and fAM concentrations, and only two out of six females and no males exhibited an increase in fPM concentrations greater than 100% (-20% SD) post GnRH administration. Conversely, only four out of six females and three out of six males had an increase in fAM concentrations greater than 100% (-20% SD) following GnRH administration. These results imply that some naked mole-rat individuals have a reduced reproductive capacity even when they are separated from the queen.

Responses to Reduced Feeding Frequency in Captive-Born Cheetahs (Acinonyx jubatus): Implications for Behavioural and Physiological Stress and Gastrointestinal Health.

Unnatural diet composition and frequent feeding regimes may play an aetiological role in the multiple diseases prevalent in captive cheetahs. This study investigated the responses of captive-born (hand-reared) cheetahs (n = 6) to a reduced feeding frequency schedule distinguished by offering larger quantities of food less frequently. The study cheetahs were fed four once-daily meals per week during the 3-week treatment period, followed by a 3-week control period in which they were fed two daily rations six days a week. Total weekly food intake was maintained throughout the study. Variations in behaviour, faecal consistency score (FCS), and faecal glucocorticoid metabolite concentration were measured. Less frequent feeding resulted in higher FCS (p < 0.01) and locomotory behaviour (p < 0.05) among the studied cheetahs. Faecal glucocorticoid metabolite concentration demonstrated an initial acute stress response to the change in feeding frequency (p < 0.05) and subsequent adaptation. The results of the FCS analysis suggest that the more natural feeding pattern could have benefited the studied cheetahs' gastrointestinal health without a significant behavioural or physiological stress response overall to the change in feeding frequency.

Validation of a field-friendly faeces drying and storage method for quantifying faecal glucocorticoid metabolites in African elephants (Loxodonta africana) opens up new perspectives for conservationists.

Faecal glucocorticoid metabolites (fGCMs) are a relevant means of non-invasively assessing adrenocortical activity and thus, a key physiological stress response in wildlife populations. However, the widespread use of fGCMs as a stress-related biomarker in conservation biology is often hampered by the logistical challenge of storing collected faecal material frozen until it reaches the laboratory for analysis. Although alternative approaches to minimize potential alteration of fGCM composition post-defecation have been recently identified, there is to our knowledge, no satisfactory alternative method established for the preservation of elephant dung. In this study, we validated a field-friendly protocol for dehydrating African elephant faeces samples using a food dehydrator with desiccant and investigated the stability of fGCM concentrations in the dehydrated faeces when stored at ambient temperature. We collected 40 faecal samples from African elephants and compared fGCM concentrations of freeze-dried and dehydrated sample sub-sets. Samples dried in the field showed a slight but significant overall -6% reduction in fGCM concentration compared with frozen control samples. However, fGCM concentrations following field dehydration protocol match those of control samples with high accuracy, as evidenced by the low bias and strong coefficient of determination between the two approaches (R2 = 0.88). In addition, over nearly 2 months, storage time at ambient temperature of the dehydrated samples had no effect on the fGCM concentrations compared with those measured in the control samples (F-statistic = 1.82; P = 0.18). Dehydrating the samples in the field thus provides an easy and cost-effective alternative to freezing, especially when working in remote areas with unstable electrical supply. Our results encourage the widespread use of fGCMs by conservationists as non-invasive means of steroid monitoring of African elephants in the current context of a general increase in wildlife welfare research. Future studies are needed to extend the use of this protocol to other species and to other steroid classes.

Validation of Enzyme Immunoassays via an Adrenocorticotrophic Stimulation Test for the Non-Invasive Quantification of Stress-Related Hormone Metabolites in Naked Mole-Rats.

Small size in mammals usually restricts long-term, frequent monitoring of endocrine function using plasma as a matrix. Thus, the non-invasive monitoring of hormone metabolite concentrations in excreta may provide an invaluable approach. The aim of the current study was to examine the suitability of enzyme immunoassays (EIAs) for monitoring responses to stressors in the naked mole-rat (Heterocephalus glaber, NMR) using urine and feces as hormone matrices. A saline control administration, and a high- and low-dose adrenocorticotropic hormone (ACTH) challenge were performed on six male and six female disperser morph NMRs. The results revealed that a 5α-pregnane-3ß,11ß,21-triol-20-one EIA detecting glucocorticoid metabolites (GCMs) with a 5α-3ß-11ß-diol structure is the most suitable assay for measuring concentrations in male urine samples, whereas an 11-oxoaetiocholanolone EIA detecting GCMs with a 5ß-3α-ol-11-one structure appears the most suitable EIA for quantifying GCMs in female urine. An 11-oxoaetiocholanolone EIA detecting 11,17 dioxoandrostanes was the most suitable EIA for quantifying GCMs in the feces of both sexes. There were sex-related differences in response to the high- and low-dose ACTH challenge. We recommend using feces as a more suitable matrix for non-invasive GCM monitoring for NMRs which can be valuable when investigating housing conditions and other welfare aspects.

Male blue wildebeest increase activity during the rut, but not at the expense of rest.

Rest is a state of adaptive inactivity that increases the efficiency of activity by regulating its timing and reducing energy use when activity is not beneficial. Thus, animals can go without rest when specific demands, such as mating, favour being awake. Sexually active male blue wildebeest (bulls) are typically territorial, and it has been reported that when a bull is protecting a harem during the mating season (rut), he neither eats nor rests. We examined the daily activity and inactivity patterns of dominant bulls by means of actigraphy for 3 months, which included the rut. We also measured faecal androgen metabolite (fAM) levels and subcutaneous temperature, both of which have variances known to delineate the rut. During the rut, wildebeest bulls experienced higher levels of activity, fAM, and a greater daily range of subcutaneous temperature. Despite previous reports, the male blue wildebeest rested daily during the rut, and while the amount of rest was low, it was not substantially lower than prior to the rut. The amount of time spent inactive increased substantially after the rut. The timing of daily activity and inactivity patterns did not vary substantially across the recording period. Across the recording period, the average daily ambient temperatures decreased (seasonality), and the subcutaneous temperature followed this pattern, although it was not as marked. It appears that in the post-rut period a substantive increase in time spent at rest occurs, potentially allowing the wildebeest bulls time to recover following a period of intense activity.

Decadal decline in maternal body condition of a Southern Ocean capital breeder.

The changing physical properties of the Southern Ocean are known to impact the recruitment and survival of Antarctic krill (Euphausia superba). For oceanic krill predators, the resulting reduced energy intake may lead to population-level effects likely preceded by an alteration in the animals' body condition. This is especially true for capital breeders that rely on stored energy for successful reproduction. One such Southern Ocean capital breeder, the southern right whale (Eubalaena australis), has been monitored over the past 43 years in their South African wintering ground. Changes in the population have been documented in the past decade, including a decreased reproductive rate and a shift in foraging strategy. To evaluate if a reduced foraging success is an underlying factor, we assessed the temporal variation in morphological body condition through aerial photogrammetry. Results showed a 23% reduction in maternal body condition, potentially contributing to the decreased reproductive rate of the population. To the best of our knowledge, this is the first study to quantify a decadal reduction in the body condition of a capital breeder dependent on Southern Ocean productivity. Understanding the bioenergetic consequences of environmental change is vital to predicting species' resilience to climate change.

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.

Aggression, Boldness, and Exploration Personality Traits in the Subterranean Naked Mole-Rat (Heterocephalus glaber) Disperser Morphs.

Animal personality traits (consistent behavioral differences between individuals in their behavior across time and/or situation) affect individual fitness through facets, such as dispersal. In eusocial naked mole-rat (Heterocephalus glaber) colonies, a disperser morph may arise with distinct morphological, behavioral, and physiological characteristics. This study aimed to quantify the personality traits of a cohort of disperser morphs of naked mole-rat (NMR). Behavioral tests were performed on twelve disperser morphs (six males and six females) in an observation tunnel system that was novel and unfamiliar. Novel stimuli (fresh snakeskin, tissue paper, and conspecific of the same sex) were introduced for fifteen minutes, and the behavioral acts of the individual were recorded. A total of 30 behaviors were noted during the behavioral tests of which eight were used to quantify aggression, boldness, and exploration. The NMR disperser morphs showed consistent individual differences in boldness, and exploration across time and test, indicating a distinct personality. In addition, new naked mole-rat responses including disturbance behaviors; confront, barricade, and stay-away, were recorded. Further investigations into the relationships between animal personality traits and social hierarchy position in entire colonies are needed for more informative results as we further investigate the role of personality in cooperatively breeding societies.

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.

Developing welfare parameters for African elephants (Loxodonta africana) in fenced reserves in South Africa.

South Africa has many fenced reserves harbouring small to medium sized populations of African elephant (Loxodonta africana), most of which have been translocated. Elephants on fenced reserves may be exposed to various management interventions and practices (translocation, hunting, darting, high tourism impact, contraception programs, disruption due to infrastructure maintenance, etc.). These factors may impact the welfare of elephants. Poor elephant welfare may have serious consequences such as increased inter- and intra-species aggression that could result in fatalities. This is the first study to attempt to define behavioural and physiological welfare parameters for free-ranging elephants on small to medium sized reserves. The eight study sites incorporated reserves with different social structure combinations, elephant life-histories, reserve sizes, habitat, management, and tourism intensity. Data collection consisted of behavioural observations (10-minute videos) as well as faecal samples. By incorporating both behavioural and physiological (faecal glucocorticoid metabolite (fGCM) concentration) parameters, we aimed to investigate whether the two parameters showed similar trends. Five behavioural categories were identified (Arousal, Assessing, Ambivalent, Ambivalent/ Body care, and Frustrated behaviour), with various detailed behaviours demonstrated by the elephants that may indicate the influence of anthropogenic disturbance and possibly impact on animal welfare. The study showed significant differences between the selected detailed behaviours, behavioural categories and fGCM concentrations of elephants across the eight reserves. History seemed to be a decisive factor, as reserves with predominantly ex-captive elephants showed higher frequencies of certain behaviours as well as higher fGCM concentrations. Age, sex, reserve size and season were also found to contribute to our defined welfare indices and fGCM concentrations. This indicates that behavioural parameters, indicative of certain behavioural states, are valuable indicators of welfare, as supported by the physiological response of the elephants. The results also highlight the importance of taking multiple specified behaviours from a category into consideration when evaluating the welfare of elephants, to account for individual variation.

A field-friendly alternative to freeze-drying faeces for glucocorticoid metabolite analyses of African wild dogs (Lycaon pictus).

Endocrine studies using faeces as hormone matrix have become increasingly popular to examine adrenocortical activity in wildlife. A prerequisite for this approach is to minimize alteration of faecal glucocorticoid metabolite (fGCM) composition post-defecation. This is done by freezing the collected material as soon as possible after collection, and removing moisture from the frozen faecal samples afterwards (usually by freeze-drying). In remote areas, freeze-drying opportunities are often limited, and in the case of the African wild dog (Lycaon pictus), established assays revealed that fGCM concentrations remain comparable for only ∼24h post-defaecation. In the present study, three cost-effective drying treatments (exposure to sunlight, placement in a solar oven, and use of a food dehydrator) were investigated as alternatives to the golden standard of freeze-drying faeces.•In comparison to freeze-dried material, African wild dog faecal samples dried through sunlight exposure, a solar oven, and use of a food dehydrator revealed no significant differences in respective fGCM concentrations measured.•A food dehydrator would be the preferable option to dry African wild dog faeces if limited electrical supply is available. This technique dries faeces the fastest, and negates any reliance on weather conditions.

Social and Seasonal Factors Contribute to Shifts in Male African Elephant (Loxodonta africana) Foraging and Activity Patterns in Kruger National Park, South Africa.

African savannah elephants (Loxodonta africana) are well-known as ecosystem engineers with the ability to modify vegetation structure. The present study aimed to examine how male elephant foraging behaviour is affected across (a) season (wet versus dry); (b) time of day (before or after noon); (c) presence or absence of other elephants; and (d) reproductive state (musth versus no musth). Six radio-collared adult elephant bulls were observed twice per week from June 2007-June 2008 in Kruger National Park (KNP), South Africa. Using generalized linear mixed effect modeling, results indicate that elephant bulls graze more during the wet season and browse more during the dry season. To potentially offset the costs associated with thermoregulation during the heat of the day, KNP elephants spent more time foraging during the morning, and more time resting during the afternoon. Male elephants also foraged significantly less when they were associated with females compared to when they were alone or with other males. This is likely due to male-female associations formed mainly for reproductive purposes, thus impeding on male foraging behaviours. In contrast, the condition of musth, defined by the presence of related physical signs, had no significant effect on foraging behaviour.

Seasonal drivers of faecal glucocorticoid metabolite concentrations in an African strepsirrhine primate, the thick-tailed greater galago (Otolemur crassicaudatus).

As global non-human primate populations show dramatic declines due to climate change, land transformation and other anthropogenic stressors, it has become imperative to study physiological responses to environmental change in order to understand primate adaptability and enhance species conservation strategies. We examined the effects of seasonality on faecal glucocorticoid metabolite (fGCM) concentrations of free-ranging male and female thick-tailed greater galagos (Otolemur crassicaudatus) in an Afromontane habitat. To do so, we established an enzyme immunoassay (EIA) for monitoring fGCM concentrations in the species using a biological validation. Following this, faecal samples were collected each month over the course of a year from free-ranging males and females situated in the Soutpansberg Mountains, Limpopo, South Africa. Multivariate analyses revealed lactation period was a driver of fGCM levels, whereas sex and food availability mostly influenced seasonal fGCM concentrations in the total population. Thus far, the results of this study show that drivers of fGCM levels, an indication of increased adrenocortical activity, in O. crassicaudatus are numerous and complex within the natural environment. The species may be adapted to such conditions and an extreme change to any one component may result in elevated fGCM levels. This increases our understanding of strepsirrhine primate physiology and offers initial insights into species adaptability to a challenging environment.

Urofaecal glucocorticoid metabolite concentrations in African penguin (Spheniscus demersus) chick populations experiencing different levels of human disturbance.

Despite the importance of ecotourism in species conservation, little is known about the industry's effects on wildlife. In South Africa, some African penguin (Spheniscus demersus) colonies have become tourist attractions. The species is globally endangered, with population sizes decreasing over the past 40 years. As African penguin chicks are altricial and unable to move away from anthropogenic stressors, it is important to evaluate the effect of tourist activities on baseline glucocorticoid levels as a measure of potential disturbance. Chicks at three study sites within two breeding colonies (Robben Island, Stony Point), with varying levels of exposure to tourism (low/moderate/high) were monitored. Urofaecal samples were collected to determine urofaecal glucocorticoid metabolite (ufGCM) concentrations as an indication of baseline stress physiology. Morphometric measurements were taken to compare body condition between sites. Penguin chicks experiencing low, infrequent human presence had significantly higher mean (± standard deviation) ufGCM levels [1.34 ± 1.70 µg/g dry weight (DW)] compared to chicks experiencing both medium (0.50 ± 0.40 µg/g DW, P = 0.001) and high levels of human presence (0.57 ± 0.47 µg/g DW, P = 0.003). There was no difference in chick body condition across sites. These results suggest that exposure to frequent human activity may induce habituation/desensitization in African penguin chicks. Acute, infrequent human presence was likely an important driver for comparatively higher ufGCM levels in chicks, though several other environmental stressors may also play an important role in driving adrenocortical activity. Nevertheless, as unhabituated chicks experiencing infrequent anthropogenic presence showed significantly higher ufGCM levels, managers and legislation should attempt to minimize all forms of activity around important breeding colonies that are not already exposed to regular tourism. Although the results of this study are crucial for developing enhanced conservation and management protocols, additional research on the long-term effect of anthropogenic activities on African penguin physiology is required.

Optimised ICP-MS quantification method for using animal faeces as a measure of protected area ecosystem health.

Pollution is a key threat to biodiversity and ecosystem health within protected areas. Using a non-invasive, multi-matrix approach, sediment, vegetation and faecal material from lion (Panthera leo) and giraffe (Giraffa camelopardalis) were collected and assessed for the simultaneous quantification of 20 trace elements using an optimised method for Inductively Coupled Plasma--Mass Spectrometry (ICP-MS). Method Linearity was confirmed over an analytical range of 0.1-50 mg/kg for aluminium (Al) and iron (Fe); 0.4-400 µg/kg for vanadium (V), cobalt (Co), molybdenum (Mo), and cadmium (Cd); 0.5-5 µg/kg for mercury (Hg); and 1-1 000 µg/kg for elements arsenic (As), boron (B), barium (Ba), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb), selenium (Se), tin (Sn), strontium (Sr) and zinc (Zn). Coefficient of determination (R2) was above 0.99 for all elements. Accuracy (% recovery) and precision (% RSD) of replicate measurements for certified reference material controls fell within 20% of expected value at lower concentrations and 15% at higher concentrations for all elements except Al. Results for instrument and method limit of detections (LOD), method limit of quantification (LOQ) and expanded uncertainty were satisfactory. Preliminary data indicate As, Cd, Cr, Cu, Hg, Ni, Pb, Se, and Zn were present in all matrices evaluated. This raises concerns regarding the combined action of multiple elements at concentrations that can adversely affect ecosystem and wildlife integrity.•Sample quantity is reduced due to the power and sensitivity of ICP-MS.•The optimised method is capable of detecting differences in trace element concentrations over large orders of magnitude in animal faeces containing different amounts of organic content.•The method can be applied to the quantification of essential and potentially toxic elements in faeces across a wide range of terrestrial species.

Physiological rhythms are influenced by photophase wavelength in a nocturnal and a diurnal rodent species from South Africa.

The quality and quantity of light changes significantly over the course of the day. The effect of light intensity on physiological and behavioural responses of animals has been well documented, particularly during the scotophase, but the effect of the wavelength of light, particularly during the photophase, less so. We assessed the daily responses in urine production, urinary 6-sulfatoxymelatonin (6-SMT) and glucocorticoid metabolite (uGCM) concentrations in the nocturnal Namaqua rock mouse (Micaelamys namaquensis) and diurnal four striped field mouse (Rhabdomys pumilio) under varying wavelengths of near monochromatic photophase (daytime) lighting. Animals were exposed to a short-wavelength light cycle (SWLC; ∼465-470 nm), a medium-wavelength light cycle (MWLC; ∼515-520 nm) and a long-wavelength light cycle (LWLC; ∼625-630 nm). The SWLC significantly attenuated mean daily urine production rates and the mean daily levels of urinary 6-SMT and of uGCM were inversely correlated with wavelength in both species. The presence of the SWLC greatly augmented overall daily 6-SMT levels, and simultaneously led to the highest uGCM concentrations in both species. In M. namaquensis, the urine production rate and urinary 6-SMT concentrations were significantly higher during the scotophase compared to the photophase under the SWLC and MWLC, whereas the uGCM concentrations were significantly higher during the scotophase under all WLCs. In R. pumilio, the urine production rate and uGCM were significantly higher during the scotophase of the SWLC, not the MWLC and LWLC. Our results illustrate that wavelength in the photophase plays a central role in the entrainment of rhythms in diurnal and nocturnal African rodent species.

Degradation of Temminck's pangolin (Smutsia temminckii) scales with a keratinase for extraction of reproductive steroid hormones.

Hormone monitoring in keratinous tissues has become increasingly popular. The insoluble keratin materials are generally pulverised before hormone extraction; however, this is difficult for thicker keratin structures like baleen plates or hooves. A new method, involving the use of keratinase, allows enzymatic digestion of keratin and hormone analysis in the resulting suspension. Pangolins are unique mammals covered in keratinous scales, which are one of the reasons these animals are extensively trafficked. This study aimed to investigate the suitability of Temminck's pangolin scales as hormone matrix for quantifying reproductive steroids. A protocol was developed to digest scales with a keratinase before measuring hormone concentrations. This method can be used to investigate the reproductive endocrinology of Temminck's pangolins but may also be extended to the other extant pangolin species.•Keratinase digests Temminck's pangolin scales and reproductive steroid metabolite concentrations are measurable in the resulting suspension.•Isopropanol is an ideal washing solvent for scales to remove surface contaminants and scale sample mass should be standardised to allow comparisons.•Any section of a scale and scales from any pangolin body region can be used as samples for hormone quantification.