In wildlife conservation, understanding the factors influencing physiological stress is essential for promoting the health and stability of managed populations. Glucocorticoids are widely used as stress biomarkers and provide valuable insights into animal well-being. Parasitic infections can elevate glucocorticoid concentrations, positioning parasites as potential physiological stressors. However, few studies have investigated relationships between parasite load and faecal glucocorticoid metabolite (fGCM) concentrations in wild mammals exposed to varying environmental and anthropogenic disturbances associated with contrasting landscape-level management strategies. In this study, we investigated drivers of fGCM concentrations in managed South African elephant populations across 19 conservation areas with contrasting management strategies and environmental conditions. Specifically, we tested whether gastrointestinal parasite load correlates positively with fGCM concentrations. Contrary to our expectations, no such correlation was found. Instead, elevated fGCM concentrations were associated with smaller conservation areas, increased human exposure from self-driving tourism, and lower food resource availability, the latter especially when elephant density is high. These results reveal that conservation management strategies, especially in fenced conservation areas, significantly influence stress-related biomarker levels in African elephants, overshadowing individual health factors such as parasite load. Our study underscores the importance of multifaceted approaches to assessing stress perceived by wildlife, considering both environmental and anthropogenic factors. This research highlights the need for nuanced management policies that address the complex interplay of stressors, advancing landscape-level conservation strategies applicable across taxa in managed habitats.

Wildlife tourism is a growing global industry with notable economic and conservation value, yet its potential impact on animal welfare is a critical concern. Traditional behavioural studies have been used to assess these effects, but non-invasive physiological measures, such as faecal glucocorticoid metabolites (fGCMs), provide direct insight into stress-related coping mechanisms. This study presents a multispecies assessment of fGCM alterations associated with tourism and season in four ungulates-impala (Aepyceros melampus), zebra (Equus quagga), blue wildebeest (Connochaetes taurinus) and giraffe (Giraffa camelopardalis)-within a small South African nature reserve. Using established species-specific enzyme immunoassays, 533 faecal samples collected during the wet and dry seasons were analysed, considering season, sex and tourist activity levels. The results revealed species-specific endocrine responses primarily to ecological factors, but also in some cases to anthropogenic factors. Blue wildebeest showed elevated fGCMs during the wet season, likely linked to reproductive events and social changes. Zebra and impala exhibited higher fGCMs during the dry season, coinciding with resource scarcity and increased tourism, with impala fGCMs significantly higher on weekends, suggesting an interaction between ecological and tourism-related stressors. Giraffe showed no seasonal or tourism-related effects, although females had higher fGCMs, likely reflecting pregnancy-related endocrine changes. These findings underscore the value of a multispecies approach to evaluate physiological impacts of wildlife tourism. Identifying differential sensitivities among species highlights the need for tailored management strategies to minimise welfare impacts, particularly during ecologically sensitive periods. As nature-based tourism expands, evidence-based practices will be essential to balance visitor experiences with conservation and animal welfare objectives.

Eusociality is exceptionally rare in mammals, and its proximate mechanisms remain poorly understood. Naked mole-rats provide a striking example, with reproduction restricted to a single queen, while all other females remain infertile1. Here we identify a chemical signal in queens that can regulate this reproductive hierarchy. Isopropyl myristate is a low-volatility ester that is enriched in queens and nearly absent from non-breeding animals. Isopropyl myristate is detected by peripheral and central olfactory neurons and elicits avoidance in high-ranking animals. Exposure alters levels of prolactin and progesterone in non-breeders to suppress reproduction. Daily addition of isopropyl myristate to a queenless colony prevented queen succession, whereas withdrawal triggered aggression and reproductive competition. Isopropyl myristate was also detected in breeding females of several Fukomys mole-rat species, but reaches higher levels in naked mole-rats, paralleling their extreme reproductive skew. These findings reveal a chemical cue that can mediate reproductive suppression in a mammal, linking insect and mammalian eusociality.

Introduction Global landscape transformations and increased resource use are leading to an overall decline in ecosystem health and natural habitat quality. Due to their low trophic position, small body size, and close association with environmental conditions, rodents can serve as effective biological indicators of ecosystem health and anthropogenic disturbance by monitoring their behavior and physiology, specifically stress-related endocrine responses. This study aimed to establish minimally invasive methods for quantifying fecal glucocorticoid metabolites (fGCMs) in six southern African rodent species (Aethomys ineptus, Lemniscomys rosalia, Mastomys coucha, Micaelamys namaquensis, Otomys angoniensis, and Steatomys pratensis).Methods Where possible, one male and one female from each species were live trapped in the Magaliesberg Biosphere, North West province, South Africa, and individually housed on-site for enzyme immunoassay (EIA) validation experiments. Biological (handling and temporary removal from enclosure) and physiological (Synacthen-induced adrenocorticotropic hormone or ACTH challenge test) stimuli were administered, and fGCM concentrations were determined from samples collected before, during, and after each intervention.Results and discussion A 5 alpha-pregnane-3 beta,11 beta,21-triol-20-one EIA (detecting fGCMs with a 5 alpha-3 beta, 11 beta-diol structure) was identified as the most suitable assay across all six species assessed. Two additional EIAs appear suitable for some of the species tested: Oxoetiocholanolone II, measuring fGCMs with a 5 beta-3 alpha-ol-11-one structure (A. ineptus, O. angoniensis, and S. pratensis); and a Corticosterone EIA (M. coucha, O. angoniensis, and S. pratensis). Establishing and validating minimally invasive techniques for monitoring stress-related animal responses in rodents can be beneficial for evaluating the impact of anthropogenic disturbances on natural environments and their associated fauna.

Diet may be fundamental to the extensive paternal care and reduced maternal care seen in bat-eared foxes (Otocyon megalotis). This termite-specialist would struggle to increase its energy intake by hunting large prey or provisioning such items to mates or pups. Consequently, lactating, physiologically challenged females need to invest more time in foraging, while males spend time with pups. However, there is little empirical evidence of the impacts of parental care on foraging behavior and stress-related hormone levels in free-living bat-eared foxes. We studied foraging behavior in 20 wild bat-eared foxes for 2 years, investigating how foraging behavior and fecal glucocorticoid metabolite (fGCM) levels varied with austral season in the study population. Thereafter, we evaluated how parental status may affect foraging rates, food sizes consumed, and fGCM levels as a proxy for physiological stress. We examined these changes in parents (n = 3) and non-parents (n = 17) as seasonal "activity" changed-that is, breeding season (pregnant phase), denning season (pup-rearing and guarding phase), and non-breeding season (independent adult phase). Small item consumption patterns mirrored overall foraging rates, which were lowest for all foxes in winter. Males increased foraging rates in spring, while all individuals ate more large items in summer. Mean fGCM levels in the population (0.41 µg g-1 organic content) were not affected by sex or austral season, but changed with seasonal activities, for parents in particular: parents had significantly lower fGCM levels in the breeding season. This may reflect reduced stress in these foxes, who successfully paired and increased their within-family socialization during the breeding season. Our findings suggest that behavioral adaptations, including foraging adaptations, are sufficient for bat-eared foxes to meet the physiological challenges of parenting. This is the first study to start unravelling the relationship between foraging rates, parenting behavior, and stress-related hormone levels in the Bat-eared Fox.

Monitoring stress physiology through non-invasive techniques is critically important for the effective management of vulnerable wildlife species, particularly those experiencing substantial anthropogenic pressures. This study aimed to validate enzyme immunoassays (EIAs) for accurately quantifying faecal glucocorticoid metabolite (fGCM) concentrations, as indicators of physiological stress in Temminck’s pangolin (Smutsia temminckii). Due to significant ethical, logistical, and conservation challenges associated with the direct handling and experimental manipulation of this threatened species, the study utilized a biological validation approach, relying on opportunistic collection of faecal samples from pangolins during their rehabilitation after confiscation from illegal wildlife trafficking. Faecal samples collected from multiple individuals at various rehabilitation facilities were analysed using a cortisol, corticosterone, two 11-oxoaetiocholanolone (72a and 72 T), and a 5α-pregnane-3ß,11ß,21-triol-20-one (37e) EIA. Among these assays, both 72a and 72 T detected significant increases (> 150

Wildlife tourism is increasing globally, with a growing proportion of activities occurring in protected areas that help them generate significant revenue. Consequently, management authorities must integrate tourism into conservation planning. Such rise in human activity in these areas can adversely affect wildlife behaviour, physiology, and reproduction. A better understanding of the impact of wildlife tourism on tiger wellbeing and spatial behaviour is therefore critical for the sustainable management of these populations. We studied the effects of wildlife tourism and anthropogenic activities on stress and reproductive physiology in wild tigers across five reserves in India. We quantified faecal glucocorticoid metabolites (fGCMs), a biomarker of stress, and faecal progesterone metabolites (fPMs), an indicator of breeding activity in females. We collected 728 presumptive tiger scat samples from core and buffer zones during both tourism and non-tourism seasons, which encompass breeding periods. Genetic analysis confirmed that 610 samples originated from tigers; these were sexed and analyzed for fGCM and fPM levels. Our findings indicate that tigers exhibited higher fGCM levels in areas with high anthropogenic activity. Further, we observed spatial variation in fGCM levels that correlated with patterns of human disturbance, including tourism, suggesting a heterogeneous distribution of stressors. As human disturbance intensified in core zones, tiger fGCM levels increased and were negatively correlated with proximity to tourism roads. Furthermore, among the areas surveyed, tigresses exhibited higher fPM levels in certain locations of the reserves, where they experienced lower fGCM levels compared to other locations. This may indicate that tigresses potentially choose locations with less disturbance for breeding. Based on these results, we discuss potential management strategies to mitigate the impact of human activities on tigers and support their reproduction.

Dietary studies on wildlife using minimally invasive techniques can elucidate the impacts of anthropogenic activities on ecosystems and native species. Investigating diet-related resource partitioning of biological indicator species can improve our understanding of mechanisms employed by animals to survive in a rapidly changing world. We compared carbon (δ13C) and nitrogen (δ15N) isotope ratios from hair tissue of four dominant southern African rodent species from the Magaliesberg Biosphere, North West province, South Africa. Hair was collected over three years during both dry and wet seasons across different land-use types: natural and peri-urban. There was significant isotopic variation between the four species across land-use types and seasons. Pairwise post-hoc comparisons of within-site diet proportions showed increased homogeneity of two synanthropic species (Lemniscomys rosalia and Mastomys coucha) in the peri-urban site, suggesting exploitation of robust, low-quality grasses and grains. Niche overlap was significantly variable between seasons at the peri-urban site, with an increased intake in grasses and maize grains during the planting and growing wet season, suggesting the rodents are more selective with increased food availability. During the dry season, food sources were shared by two non-commensal species (Aethomys ineptus and Micaelamys namaquensis), and the two synanthropic species shared three food sources. Overall seasonal variation across sites may indicate variable diet plasticity in the four generalist species, but specialists in increasingly encroached upon and urbanized seasonal landscapes may struggle to adapt to available food and face extirpation.

Literature on the adaptability and environmental processing abilities of ex-captive (rewilded) African elephants (Loxodonta africana) is sparse, emphasising the importance of this research area. By broadening our knowledge on the topic of rewilded elephant behaviour, we can generate a realistic expectation for stakeholders wanting to secure locations for these captive elephants with the aim of rewilding them. We studied 11 African elephants who have been rewilded onto various fenced reserves in South Africa. We measured their adaptability and response to their environment by comparing their behavioural frequencies within four categories and their physiological responses (faecal glucocorticoid metabolite (fGCM) concentrations), to those observed for free-roaming elephants in South Africa. All study animals were grouped into three age/sex categories (Adult females (AF); Adult males (AM); Sub-adult females (SAF)). The results demonstrated that rewilded elephants expressed similar behavioural frequencies to their wild counterparts, except within the "Attentive" category, where both rewilded AMs and SAFs showed significantly lower frequencies than wild elephants. On the contrary, rewilded AFs and SAFs had comparatively higher fGCM concentrations than wild elephants. Through individual comparisons, it was evident that rewilded elephants have adopted unique mechanisms to process environmental stimuli. When the relationship between behavioural and physiological responses was investigated, certain rewilded elephants showed a strong relationship between the two parameters. However, for other elephants, there was no clear correlation between behavioural frequencies and fGCM concentrations. These distinctive differences might largely be influenced by personality traits that will determine whether the elephants respond actively or passively to their environment. This study has shown that rewilded elephants can adapt to wild environments after long-term captivity and that each of them implemented unique ways of coping with both natural and management-related pressures in the different reserves.

Global landscape transformations are a result of a growing human population and the subsequent increased use of natural habitats. Local species extinctions across various transformed landscapes emphasise the importance of monitoring wildlife responses to anthropogenic activities. Rodents are valuable biological indicators of anthropogenic disturbance and, subsequently, ecosystem health. The study quantified faecal glucocorticoid metabolites (fGCMs) as a stress‐related biomarker in two dominant southern African murids, Lemniscomys rosalia (single‐striped grass mouse) and Mastomys coucha (southern multimammate mouse), across dry and wet seasons within minimally and moderately disturbed landscapes in the Magaliesberg Biosphere, South Africa. Faecal samples were collected from live‐trapped individuals, and fGCMs were quantified using a previously validated 5α‐pregnane‐3β,11β,21‐triol‐20‐one enzyme immunoassay (detecting fGCMs with a 5α‐3β, 11β‐diol structure). Mastomys coucha showed a significant increase in fGCM concentrations during the wet season (58 and 22% higher in the minimally and moderately transformed sites, respectively). For L. rosalia , fGCM concentrations were not significantly different between seasons. Landscape‐specific fGCM concentrations did not differ significantly in either species, reflecting the generalist, synanthropic nature of both species. While these species are morphologically and ecologically similar, their seasonal fGCM profiles diverged significantly in natural landscapes. The 58% increase in median fGCM concentrations for M. coucha was not seen in L. rosalia . This physiological differentiation between species may perhaps be elucidated by the energetic and behavioural strategies they employ to cope with seasonal resource fluctuations in natural habitats. Despite their phenotypic plasticity and behavioural adaptability, dominant generalist species such as M. coucha are affected by seasonal shifts. Greater climatic fluctuations across seasons should be investigated as they may lead to chronic stress‐related hormone responses, and, in extreme cases, reduced survival and local extinctions.

In African elephant (Loxodonta africana) societies, matriarchs hold the highest social rank, relying on long-term ecological knowledge to maintain group cohesion and coordinate collective movement. Although such leadership is widely recognized as behaviourally and cognitively demanding, we seldom quantify potential physiological costs. Here, we report higher faecal glucocorticoid metabolite (fGCM) concentrations in a matriarch compared to all other members of her family group in a semi-arid, fenced reserve in the Nama-Karoo biome of South Africa. From 2022–2024, we collected 372 faecal samples from all 18 individuals in the population and analyzed fGCM concentrations using a Bayesian framework. Demographic variables did not predict fGCM levels, but individual-level variation was noted. Posterior estimates indicated that the matriarch, Zinkwazi, exhibited higher fGCM concentrations than any other herd member. As no pregnancies occurred during the study period, elevated fGCM levels are unlikely to reflect reproductive state, suggesting instead that responsibilities of leadership may contribute to sustained glucocorticoid output. These findings highlight the possibility that matriarchal leadership carries measurable physiological costs. Understanding such costs may provide new insight into elephant social dynamics, welfare, and management in constrained or resource-limited landscapes.

Reproduction in long-lived, iteroparous mammals requires careful allocation of energetic resources. This is especially true in capital breeding species such as the southern right whale (Eubalaena australis), where reproductive success depends on body condition, as accumulated reserves must fuel the high energetic demands, especially during lactation. Understanding the physiological mechanisms underpinning maternal energy balance is therefore critical for assessing reproductive capacity and maternal investment strategies. This study combined body condition metrics derived from aerial photogrammetry with endocrine correlates (glucocorticoids and triiodothyronine; hormones associated with energy mobilisation and regulation of metabolism) measured in blubber biopsies to establish baseline measures of metabolic function in lactating southern right whales over the calving season (July-September). Analyses revealed a positive correlation between glucocorticoids and triiodothyronine, strongest in lactating females. A clear decline in both hormones was observed toward the end of the calving season, consistent with reduced maternal metabolic activity and corresponding to slowed calf growth rates. No significant differences in hormone concentrations were detected between demographic groups (n = 15 lactating females, n = 8 unaccompanied adults), nor maternal (n = 9 good condition, n = 3 poor condition) or calf body condition categories (n = 5 good condition, n = 7 poor condition), although this may relate to the study's limited sample size. By linking endocrine profiles with body condition, this study provides novel physiological context for understanding maternal investment strategies in southern right whales. The findings highlight how intra-seasonal energetic demands are hormonally mediated during lactation and demonstrate the feasibility of integrating photogrammetry with endocrine monitoring in free-swimming baleen whales. Establishing these physiological baselines is critical for detecting early indicators of reproductive stress and for informing conservation strategies in recovering populations.

Fenced reserves are widely used to conserve and manage African savanna elephants (Loxodonta africana) in South Africa. However, the effects of fencing and fence removal on elephant wellbeing, movement and ecosystem dynamics remain limited in understanding, with few studies incorporating these elements. We hypothesised that fence removal would increase elephant movement flexibility and range, reduce behavioural disturbance and increase sociality, reduce stress-related biomarkers and redistribute browsing pressure. We evaluated how a resident elephant population in a private reserve in the Eastern Cape, South Africa, responded to the removal of two internal fences by integrating focal behavioural observations, faecal glucocorticoid metabolite (fGCM) analyses, NDVI-based vegetation assessments and GPS collar data collected before and after fence removal. Fence removal increased home-range extent, seasonal mobility and inter-herd spatial overlap, with elephants incorporating newly accessible habitat at variable rates. Initial movement was towards lower density environments during the exploratory phase, with greater distribution in space utilisation over time. Behavioural responses indicated short-term increases in aggression, vigilance and disturbance-related behaviours immediately after fence removal, followed by stabilisation, reduced aggression and increased affiliative behaviour over time. Activity budgets shifted towards increased locomotion and reduced foraging, consistent with exploratory behaviour. fGCM concentrations declined significantly following fence removal and remained significant after accounting for demographic and environmental variables, suggesting reduced physiological stress. Vegetation dynamics were spatially heterogeneous yet comparable between areas of elephant presence and absence. This suggests that expanded access redistributed browsing pressure without causing disproportionate vegetation loss with vegetation change primarily driven by environmental variability and not elephant access. These findings suggest that fence removal can promote more natural movement, behavioural responses and physiological regulation, while maintaining vegetation dynamics consistent with background climatic variability. Fence removal may therefore provide an alternative or complementary approach to population management by alleviating spatial constraints and redistributing ecological pressure across the landscape.

Environmental and anthropogenic factors significantly drive adrenocortical activity of animals, affecting their behaviour, distribution and survival. Understanding how animals respond to such drivers is essential for effective conservation. Spraint samples from free-ranging African clawless otters (Aonyx capensis) and camera trap data were collected from study sites categorized as natural or artificially transformed based on differences in anthropogenic disturbance levels. To determine if there were significant differences in faecal glucocorticoid metabolite (fGCM) concentrations between the Natural (Kalkfontein Nature Reserve) and Transformed (Millstream Farm) sites, we ran a linear model that included sex, season, habitat type and their interaction. fGCM concentrations differed significantly between the sexes (df = 1; F 1,106 = 11.180; P = 0.001); with males (n = 32; 0.608 ± 0.367 μg/g DW) having significantly higher fGCM concentrations compared to females (n = 79; 0.414 ± 0.399 μg/g DW, P = 0.006). The fGCM concentrations differed significantly between seasons (df = 1; F 1,106 = 45.268; P < 0.001), with those in the dry winter season significantly higher (n = 66; 0.631 ± 0.420 μg/g DW), compared to the wet summer season (n = 45; 0.234 ± 0.199 μg/g DW). The fGCM concentrations differed significantly between habitat type (df = 1; F 1,106 = 6.026; P = 0.016) with fGCM concentrations of individuals from the KNR natural site (n = 34; 0.285 ± 0.199 μg/g DW) being significantly lower compared to those measured in individuals at the MF transformed site (n = 77; 0.552 ± 0.436 μg/g DW). Finally, the difference in fGCM concentrations between locations however were not dependent on season (df = 1; F 1,106 = 0.369; P = 0.544). Anthropogenic disturbance and alterations to the natural and varied prey-base of African clawless otters in an anthropogenically transformed site significantly affect their adrenocortical activity. Future research should focus on how these animals respond to anthropogenic disturbance, and what effects disturbance has on their behaviour, distribution and fitness. Mitigating human-otter conflict requires incorporating such behavioural responses into management strategies.

Quantification of faecal glucocorticoid metabolites (fGCMs) is a popular non-invasive technique for monitoring wildlife's response to stressors, demanding an understanding of the stability of fGCM concentrations post-defaecation to ensure comparability of determined fGCM values across samples. To provide species-specific recommendations for the duration within which sampling can take place, we measured the rate at which the fGCM concentrations of nine different species changed throughout a 7-day period post-defaecation. In this study, we explored the temporal dynamics of fGCM concentrations in nine species across three feeding classes (ruminants, hindgut fermenters and carnivores): impala (Aepyceros melampus), giraffe (Giraffa camelopardalis), blue wildebeest (Connochaetes taurinus), plains zebra (Equus quagga), African elephant (Loxodonta africana), white rhino (Ceratotherium simum), cheetah (Acinonyx jubatus), spotted hyena (Crocuta crocuta) and leopard (Panthera pardus). Utilizing enzyme immunoassays already established for each of the focal species, we identified broader feeding class-specific patterns. All herbivores exhibited a significant decrease in fGCM concentrations over time, starting from 6 h (impala) to 48 h (giraffe, blue wildebeest, white rhino and African elephant) post-defaecation. For carnivores, concentrations remained fairly comparable for 12-24 h, after which fGCM concentrations either decreased (spotted hyena), increased (leopard) or remained stable (cheetah), with notable variation in triplicate concentrations (cheetah and leopard). These findings offer insights into scheduling faecal sampling for endocrine monitoring, particularly from free-roaming wildlife, to ensure comparability of determined hormone metabolite concentrations. Furthermore, the species-specific variation in fGCM concentration post-defaecation demonstrated in this study underlines the necessity to investigate every new species to ensure accurate and comparable results. Future studies ought to investigate how the mass of collected material, sex and drying methodologies affect the measurement of fGCMs post-defaecation.

Urban wildlife must cope with diverse challenges and stressors, including human presence. However, in addition to being a disturbance, humans can provide energy-rich food and protection from predators. We evaluated the impact of human presence on red-winged starlings (Onychognathus morio) in a highly urbanised environment using faecal glucocorticoid metabolite (fGCM) concentrations as a stress-related biomarker. We performed an adrenocorticotropic hormone (ACTH) challenge to validate a non-invasive method for quantifying glucocorticoids in red-winged starlings. Using this method, we quantified fGCMs in excreta collected from free-living starlings during weekdays (high human presence) and weekends (low human presence) to determine the birds' responses to fluctuating human numbers. Following the ACTH challenge, starlings' circulating glucocorticoid (GC) concentrations increased by 127 % within 30 min and the corresponding fGCM concentrations increased within 1 h of injection. Of the four enzyme immunoassays (EIA) tested, an 11-oxoaetiocholanolone EIA, performed best, detecting a 310 % increase in fGCM concentrations post-ACTH challenge and suggested a 1-h lag between injection and peak fGCM excretion in this species. Human foot-traffic was significantly higher on weekdays compared to weekends, yet free-living red-winged starlings showed overall 30.4 % lower fGCM concentrations on weekdays compared to weekends. Red-winged starlings consume a higher proportion of anthropogenic food on weekdays than weekends and we cannot rule out the possibility that diet-related alteration in gut passage time affect fGCM concentrations. However, the correlation between fGCMs and human foot traffic may also suggest urban red-winged starlings benefit from human presence. Our results raise the possibility that, under certain conditions, the benefits associated with human presence outweigh potential negative effects associated with human activity, at least during the non-breeding season.

Gestation length is a key reproductive parameter influencing fecundity, population growth rates, and the recovery potential of baleen whales. However, direct knowledge of the gestation length in these large mammals remains limited, primarily inferred from whaling and observational data. Over the past decade, southern right whales have experienced a decline in reproductive success, likely linked to climate-change-induced shifts in foraging conditions. Understanding the population-level consequences of these changes requires detailed longitudinal reproductive data. This study analyzes multiyear steroid hormone profiles in the baleen of adult female southern right whales stranded along the South African coast. Results show an extended hormonal pattern characterized by two peaks in progestogens between 20 and 25 months-suggesting putative pregnancies lasting substantially longer than previous estimates. Sharp estrogen peaks during periods of elevated progestogen phases may indicate hormonal regulation of myometrial contractions at birth. A positive correlation between progestogens and glucocorticoids suggests a role for glucocorticoids in pregnancy maintenance, while androgens provide limited insight into female reproduction in this species. These findings imply a longer-than-expected gestation period for southern right whales and potentially across the balaenid family. This has important implications for understanding the timing and location of conception, relevant for conservation management strategies. Multipopulation studies alongside individual sighting histories are recommended to refine our understanding of southern right whale reproduction further.

Human activities have increased pollution and toxic element concentrations in soils across the Earth's surface. These activities could have profound implications for wildlife that directly or incidentally ingest soil during foraging, and for humans that consume animals as a primary source of protein. To date, levels of soil ingestion in large herbivores and species-specific vulnerability to toxic element exposure via this pathway have not yet been assessed. Here, we tested the hypothesis that animals feeding closer to the ground ingest more soil than their browsing counterparts. Across a community of 16 African herbivore species, we found that soil ingestion was highest in grazing (blue wildebeest, white rhino and buffalo) and fossorial (warthog and porcupine) animals. This translated to 20-60 % higher total element intake for chromium, cobalt, tin, lead, vanadium and arsenic in these groups. Faecal and fur concentrations were similarly elevated in these species, highlighting that the toxic elements ingested from soil are assimilated into body tissues with potential repercussions for animal and human health. In ungulates, soil ingestion rates align with species-level hypsodonty (height of the tooth crown). We propose that hypsodonty can be used as a proxy for identifying species-specific vulnerability to toxic-element exposure at broad scales. The non-invasive framework developed here, may be applied to monitoring wild herbivore exposure to toxic elements and may be particularly relevant for ongoing conservation and rewilding efforts in areas with high levels of anthropogenic pollution.

As part of its mission to advance the field of wildlife endocrinology, the International Society of Wildlife Endocrinology aims to develop cost-effective antibodies and enzyme immunoassay kits that support research across a diverse range of species and sample matrices. To provide additional options for the quantification of faecal glucocorticoid metabolites (fGCMs), an antibody against 11-oxoetiocholanolone-17-carboxymethyl oxime (CMO) was generated in rabbits, and an enzyme immunoassay incorporating a horseradish peroxidase-conjugated label and 11-oxoetiocholanolone standard has been developed, designed for use with anti-rabbit IgG secondary antibody coated plates. This mini-kit was used to quantify glucocorticoid metabolites with a 5β-3α-ol-11-one structure in faecal extracts from 23 species: African and Asian elephants, Alpine chamois, American bison, Bengal tiger, blue wildebeest, blue-and-yellow macaw, brushtail possum, cape buffalo, fat-tailed dunnart, Florida manatee, ghost bat, giraffe, golden langur, Gould's wattled bat, hippopotamus, Leadbeater's possum, mandrill, okapi, roan antelope, samango monkey, short-beaked echidna, and western lowland gorilla. Pharmacological (adrenocorticotropic hormone challenge) and biological (inter-zoo translocation, wild capture, social disruption, illness/injury and veterinary intervention) challenges resulted in expected increases in fGCM concentrations, and in a subset of species, closely paralleled results from a previously established immunoassay against 11-oxoetiocholanolone-17-CMO. Two additional species tested, Krefft's glider, which showed contradictory results on this assay compared to a previously validated enzyme immunoassay (EIA) and Ankole cow, where the magnitude increase post-event did not quite reach the 2-fold change criteria, highlight that differences in excreted faecal metabolites across species mean that no EIA will be suitable for all species. This assay provides a valuable new option for assessing adrenal activity across taxa using a group-specific antibody. Future studies should put similar emphasis on validation to determine optimal assay choice for measuring fGCMs in a variety of species.

African clawless otters (Aonyx capensis) are opportunistic feeders with a broad dietary niche. Variation in their diet can be influenced by environmental and anthropogenic factors, which can affect seasonal and longitudinal prey availability. Flexibility in the diet allows African clawless otters to adapt to these changes and exploit novel prey items when available. Seasonal examination of otter spraints from three different locations across South Africa demonstrates that African clawless otters are able to shift from their preferred crab-based diet to a fish- or insect-based diet in response to environmental and anthropogenic drivers. Here we provide direct evidence of African clawless otters in terrestrial environments shifting to an insect-dominated diet when this resource is available. The dietary plasticity and response of this species to the shifts in available prey items may be an important factor for future consideration in conservation management of the species.