White Rhinoceros Research Articles

Evolutionarily Young African Rhinoceros Gammaretroviruses.

High-throughput sequences were generated from DNA and cDNA from four Southern white rhinoceros (Ceratotherium simum simum) located in the Taronga Western Plain Zoo in Australia. Virome analysis identified reads that were similar to Mus caroli endogenous gammaretrovirus (McERV). Previous analysis of perissodactyl genomes did not recover gammaretroviruses. Our analysis, including the screening of the updated white rhinoceros (Ceratotherium simum) and black rhinoceros (Diceros bicornis) draft genomes identified high-copy orthologous gammaretroviral ERVs. Screening of Asian rhinoceros, extinct rhinoceros, domestic horse, and tapir genomes did not identify related gammaretroviral sequences in these species. The newly identified proviral sequences were designated SimumERV and DicerosERV for the white and black rhinoceros retroviruses, respectively. Two long terminal repeat (LTR) variants (LTR-A and LTR-B) were identified in the black rhinoceros, with different copy numbers associated with each (n = 101 and 373, respectively). Only the LTR-A lineage (n = 467) was found in the white rhinoceros. The African and Asian rhinoceros lineages diverged approximately 16 million years ago. Divergence age estimation of the identified proviruses suggests that the exogenous retroviral ancestor of the African rhinoceros ERVs colonized their genomes within the last 8 million years, a result consistent with the absence of these gammaretroviruses from Asian rhinoceros and other perissodactyls. The black rhinoceros germ line was colonized by two lineages of closely related retroviruses and white rhinoceros by one. Phylogenetic analysis indicates a close evolutionary relationship with ERVs of rodents including sympatric African rats, suggesting a possible African origin of the identified rhinoceros gammaretroviruses. IMPORTANCE Rhinoceros genomes were thought to be devoid of gammaretroviruses, as has been determined for other perissodactyls (horses, tapirs, and rhinoceros). While this may be true of most rhinoceros, the African white and black rhinoceros genomes have been colonized by evolutionarily young gammaretroviruses (SimumERV and DicerosERV for the white and black rhinoceros, respectively). These high-copy endogenous retroviruses (ERVs) may have expanded in multiple waves. The closest relative of SimumERV and DicerosERV is found in rodents, including African endemic species. Restriction of the ERVs to African rhinoceros suggests an African origin for the rhinoceros gammaretroviruses.

Data: Feeding ecology of southern white rhinos translocated to a protected ranch in central Uganda

Data: Feeding ecology of southern white rhinos translocated to a protected ranch in central Uganda

Effect of fecal preservation method on captive southern white rhinoceros gut microbiome

AbstractThe southern white rhinoceros (Ceratotherium simum simum) faces an uncertain future in the wild due to increased poaching pressure and habitat fragmentation, thus the management of reproductively successful populations is of critical importance. Successful reproductive outcomes in rhinoceros may be mediated by diet and gut microbial diversity; therefore, understanding gut microbial dynamics within and between captive and wild populations may help improve conservation efforts. Accordingly, gut microbiome preservation methods are needed that are practical for in situ field sampling of wild populations. We evaluated the efficacy of 3 different preservation methods over 2 timepoints for stabilizing microbial communities in feces from southern white rhinoceros (n = 10) at the North Carolina Zoo in Asheboro, North Carolina, USA, during July–September 2020 and January–March 2021. Samples were immediately frozen at −80°C, stored in PERFORMAbiome™·GUT (PB) tubes or stored in 95% ethanol at ambient temperatures (to simulate field conditions), and processed after 14 or 230 days post‐collection. We quantitatively compared alpha and beta diversity across microbial communities and identified taxa that were enriched in each treatment group. Samples preserved in 95% ethanol consistently harbored lower Shannon diversity index (SHDI) and Simpson's diversity (SDI) values compared to Frozen and PB samples. This trend was apparent in both Ethanol day‐14 samples (SHDI 4.94; SDI 0.98) versus Frozen day‐14 (SHDI 5.19; W = 518, P < 0.001; SDI 0.99; W = 476, P < 0.001) and PB day‐14 (SHDI 5.15; W = 430, P < 0.01; SDI 0.99; W = 1075, P = 1) samples, and in Ethanol day‐230 samples (SHDI 4.48; SDI 0.97) versus Frozen day‐230 (SHDI 5.18; W = 0, P < 0.05; SDI 0.99; W = 0, P = 0.032) and PB day‐230 (SHDI 5.23; W = 0, P < 0.05; SDI 0.99; W = 0, P = 0.032) samples. Ethanol day 230 samples differed (P < 0.05) from all other treatments in both alpha and beta diversity indices. Notably, frozen and PB preservation methods maintained compositionally similar microbial communities across both time points. Our results indicate that PB tubes stored at ambient temperatures perform similarly to freezing at −80°C, highlighting their utility for microbiome fieldwork applications. Identifying optimal and versatile microbiome preservation techniques will enable future studies of the gut microbiome in reproductively‐successful wild populations, an effort central to conservation efforts in the southern white rhinoceros and other threatened species.

Feeding, mating and animal wellbeing: new insights from phylogenetic comparative methods.

Feeding, mating and animal wellbeing: new insights from phylogenetic comparative methods.

Pharmacokinetics of intravenous propofol in southern white rhinoceros (Ceratotherium simum simum) after intramuscular etorphine-butorphanol-medetomidine-azaperone.

To determine the pharmacokinetics of a single bolus of intravenous (IV) propofol after intramuscular administration of etorphine, butorphanol, medetomidine, and azaperone in 5 southern white rhinoceros to facilitate reproductive evaluations. A specific consideration was whether propofol would facilitate timely orotracheal intubation. 5 adult, female, zoo-maintained southern white rhinoceros. Rhinoceros were administered etorphine (0.002 mg/kg), butorphanol (0.02 to 0.026 mg/kg), medetomidine (0.023 to 0.025 mg/kg), and azaperone (0.014 to 0.017 mg/kg) intramuscularly (IM) prior to an IV dose of propofol (0.5 mg/kg). Physiologic parameters (heart rate, blood pressure, respiratory rate, and capnography), timed parameters (eg, time to initial effects and intubation), and quality of induction and intubation were recorded following drug administration. Venous blood was collected for analysis of plasma propofol concentrations using liquid chromatography-tandem mass spectrometry at various time points after propofol administration. All animals were approachable following IM drug administration, and orotracheal intubation was achieved at 9.8 ± 2.0 minutes (mean ±SD) following propofol administration. The mean clearance for propofol was 14.2 ± 7.7 ml/min/kg, the mean terminal half-life was 82.4 ± 74.4 minutes, and the maximum concentration occurred at 2.8 ± 2.9 minutes. Two of 5 rhinoceros experienced apnea after propofol administration. Initial hypertension, which improved without intervention, was observed. This study provides pharmacokinetic data and insight into the effects of propofol in rhinoceros anesthetized using etorphine, butorphanol, medetomidine, and azaperone. While apnea was observed in 2 rhinoceros, propofol administration allowed for rapid control of the airway and facilitated oxygen administration and ventilatory support.

Exploring the behaviors and social preferences of a large, multigenerational herd of zoo-housed southern white rhinoceros (Ceratotherium simum simum).

The zoo-housed southern white rhinoceros (SWR) population is of special concern due to their lack of consistent breeding success. An enhanced understanding of SWR social preferences could better inform management planning by promoting natural social relationships, which can positively affect their well-being. The large, multigeneration herd housed at the North Carolina Zoo provides an ideal opportunity to examine rhino sociality across different ages, kin types, and social groupings. Eight female rhinos' social and nonsocial behaviors were recorded from November 2020 through June 2021 across 242 h. Activity budget analyses revealed strong seasonal and temporal variations in grazing and resting behaviors, with no stereotypic behaviors recorded. Bond strength calculations suggested that each female maintained strong social bonds with one to two partners. Beyond mother-nursing calf bonds, we found that the strongest social ties were maintained between calf-less adults and subadults in these dyads. Considering these findings, we recommend that management plans attempt to house immature females with calf-less adult females, as they may be necessary to the social landscape of immature females and, ultimately, improve their welfare.

A review of clostridial diseases in rhinoceroses

AbstractAlthough rhinoceros conservation efforts are focused on anti‐poaching and combating wildlife trade, infectious diseases are an increasing threat to both free‐ranging and captive rhinoceros populations. Among these, clostridial infections with Clostridium perfringens, Paeniclostridium sordellii, and Clostridium novyi have caused acute disease in black and white rhinoceroses, characterized by a high mortality rate within very brief time spans. The acute nature, as well as limited knowledge of epidemiology, diagnosis, and management, make clostridial diseases an important threat to rhinoceros conservation. This article reviews historical cases of clostridial disease in rhinoceros with the aim of formulating a clearer understanding of the disease's epidemiology and using this information to make recommendations for its management in free‐ranging rhinoceroses. Acute colic and sudden death in rhinoceroses, together with necropsy findings of segmental hemorrhagic enteritis, should lead towards a tentative diagnosis of enteric clostridial disease, although detection and identification of specific toxins are required for a definitive diagnosis. Our findings indicate the need for further research into clostridial disease dynamics in wildlife species and provide the basis for this research in rhinoceroses.

Rhinoceros accounting in Kruger National Park, South Africa

Trends in rhinoceroses (rhinos) in Kruger National Park (Kruger) is of key concern. Poaching drives trends in the Park. Reconciling annual population estimates with yearly reports of poached carcasses fuels public critique. We account for trends in rhinos by extracting time series of estimates. Progressively modelling influences of management introductions and removals, effects of environmental variation and rhino density, direct impacts of poaching, consequences of imperfect carcass detection, and indirect impacts of deaths of dependent calves form the basis of accounting for rhinos. Models that considered all these influences explained 93% of white and 83% of black rhino population trends. In addition, the models predicted 2,515 white and 225 black rhinos, similar to estimates of 2,607 (95% CI: 2,475–2,752) and 202 (95% CI: 172–237) during 2020 respectively. The best model, however, predicts slow recovery with a white rhino population equivalent to pre-poaching achieved between 2030 and 2040. For black rhinos, recovery to pre-poaching population size would be between 2040 and 2050. The poaching onslaught in Kruger disrupted eruptive white rhino dynamics and prevented black rhinos from transitioning into eruptive dynamics. Authorities require innovative approaches within and beyond Kruger to help re-ignite rhino conservation.

Comparative analysis of gestation in three rhinoceros species (Diceros bicornis; Ceratotherium simum; Rhinoceros unicornis)

This comparative analysis evaluated endocrine profiles and gestation length data of captive pregnant black rhinoceros (Diceros bicornis), white rhinoceros (Ceratotherium simum), and greater one-horned (GOH) rhinoceros (Rhinoceros unicornis). Hormone profiles were collected over three decades as part of pregnancy diagnoses. After the third month of gestation, the luteo-placental shift in progesterone production in pregnant rhinoceroses causes a significant increase in the concentration of faecal progesterone metabolites. We defined a laboratory-specific value of 1000 ng/g faeces as a threshold for incipient feto-placental progesterone production. Using this value allowed a comparison between species and revealed significant individual differences within a species. The mean ± SEM gestation days for reaching the 1000 ng/g faeces threshold were 89.5 ± 2.9 (range 56–138 days; n = 39) in black, 96.0 ± 2.6 (58–138; n = 39) in white, and 117.8 ± 5.3 (74–173; n = 19) in GOH rhinoceroses. For the calculations of gestation length, we complemented our results from three decades of reproductive monitoring with data from the literature, resulting in about 70 values for each species. Gestation length in the black, the white and the GOH rhinoceros was 460.6 ± 1.5 (range: 436 – 486), 503.8 ± 1.3 (range: 480 – 525) and 480.5 ± 1.1 (range: 453 – 505) days, respectively. Daylight length significantly affected gestation length, while the sex of offspring had no effect. On average, pregnancies with parturitions in spring and summer were one week shorter than those in autumn and winter. Although rhinoceroses are non-seasonal breeders, most parturitions in captivity occur in autumn and winter. We also analysed preconception endocrine profiles in the white rhinoceros. Conceptions in this species occurred after oestrous cycles of approximately 35 days (n = 18), 70 days (n = 3), 15 days (n = 1), after periods of ovarian inactivity (n = 5), and during a foal heat within one month after stillbirth parturition (n = 1). In conclusion, this study provides a comprehensive overview of gestational parameters in three rhinoceros species.

Prolactin enzyme-linked immunosorbent assay for rhinoceroses – Another tool for assessing reproductive function and dysfunction in this taxon

For decades, progesterone and its metabolites have served as the primary biomarkers for monitoring reproductive activity in rhinoceroses, whereas protein hormones have received little attention despite their potential value in understanding reproductive function and dysfunction in this taxon. The goals of this study were to: 1) identify an enzyme-linked immunosorbent assay (ELISA) effective in measuring rhinoceros serum prolactin, 2) generate representative prolactin data in male and female rhinoceroses in diverse reproductive states, and 3) characterize prolactin throughout pregnancy in a white rhinoceros that exhibited mid-gestation lactation. Our results indicated that an equine prolactin ELISA by CUSABIO® is effective in measuring serum prolactin concentrations in white, black and Sumatran rhinoceroses. Preliminary data suggested that prolactin is lowest in males and acyclic females, but also appeared low during post-partum lactation. In contrast, prolactin concentrations were elevated in pregnant females and moderate in sexually mature females experiencing reproductive cyclicity. Prolactin increased following conception and generally continued to rise throughout pregnancy in the one pregnant white rhinoceros profiled herein. Spikes and dips in prolactin and progesterone, respectively, were documented around the time of mid-gestation mammary development and colostrum production in this individual and may provide some clues into the physiological triggers of this newly described aberrant reproductive condition. In conclusion, we have identified a new tool for studying reproductive activity in rhinoceroses, generated preliminary data, and revealed an intriguing relationship between prolactin fluctuations and premature lactation. This work provides the foundation for larger, focused studies on the role of prolactin in this taxon.

The effects of animal transfers on the reproductive success of female white rhinoceroses (Ceratotherium simum simum) kept in European zoos

The Southern white rhinoceros (Ceratotherium simum simum) has been kept in European zoos since the 1960s. However, captive breeding success has been low, with social group composition, group size, and available space all playing a role. Female rhinoceroses that have never bred or not bred for a long time have a particularly increased risk of developing reproductive tract pathologies, often resulting in infertility at a young age. One management measure to stimulate breeding is to transfer non-reproducing animals to other zoos. This study evaluated the success of transfers of 4 – 28 years old white rhinoceroses between European zoos. We analyzed n = 90 (45 males and 45 females) transfers of white rhinoceroses between 1990 and 2018. Fecal progesterone metabolite levels were analyzed for a subset of female rhinoceroses. The success of a transfer was defined as a calf born within five years. The success rate after female transfers was 26.7%; however, when the age limit of transferred females is set at 18 years, the success rate was 44.4%. The success rate after a male transfer was 23.2%. In transferred females, 83% of births occurred within three years after a transfer. Births following the arrival of a new male were distributed over five years. After a male transfer, endocrine data were determined in 26 of 82 females affected by the transfer. Positive development of estrous cycle activity after the arrival of the new bull occurred in 13 females. In summary, the success of the transfers in terms of offspring birth and endocrine stimulation of cycle activity was lower than anticipated, and sometimes a considerable amount of time elapsed before a calf was born. Nonetheless, transfers are essential to promote breeding. The relatively low success of the transfers analyzed in this study relates to the partially advanced age of the white rhinoceroses studied. Transfers of juvenile or adolescent females currently conducted between European zoos reveal a better birth rate than the present study.

Capture and transport of white rhinoceroses (Ceratotherium simum) cause shifts in their fecal microbiota composition towards dysbiosis.

Translocations of Rhinocerotidae are commonly performed for conservation purposes but expose the animals to a variety of stressors (e.g. prolonged fasting, confinement, novel environment, etc.). Stress may change the composition of gut microbiota, which can impact animal health and welfare. White rhinoceroses in particular can develop anorexia, diarrhea and enterocolitis after translocation. The aim of this study was to investigate the associations of age, sex and translocation on the rhinoceros' fecal bacterial microbiota composition. fecal samples were collected from rhinoceroses at capture (n = 16) and after a >30-hour road transport (n = 7). DNA was isolated from these samples and submitted for 16S rRNA V3-V4 phylotyping. Alpha diversity indices of the rhinoceros' fecal microbiota composition of different age, sex and before and after transport were compared using non-parametric statistical tests and beta diversity indices using Permutational Multivariate Analysis Of Variance (PERMANOVA). Resulting P-values were alpha-corrected (Padj.). Alpha and beta diversity did not differ between rhinoceroses of different age and sex. However, there was a significant difference in beta diversity between fecal samples collected from adult animals at capture and after transport. The most abundant bacterial phyla in samples collected at capture were Firmicutes and Bacteroidetes (85.76%), represented by Lachnospiraceae, Ruminococcaceae and Prevotellaceae families. The phyla Proteobacteria (Padj. = 0.009) and Actinobacteria (Padj. = 0.012), amongst others, increased in relative abundance from capture to after transport encompassing potentially pathogenic bacterial families such as Enterobacteriaceae (Padj. = 0.018) and Pseudomonadaceae (Padj. = 0.022). Important commensals such as Spirochaetes (Padj. = 0.009), Fibrobacteres (Padj. = 0.018) and Lachnospiraceae (Padj. = 0.021) decreased in relative abundance. These results indicate that the stressors associated with capture and transport cause an imbalanced fecal microbiota composition in white rhinoceroses that may lead to potentially infectious intestinal disorders. This imbalance may result from recrudescence of normally innocuous pathogens, increased shedding of pathogens or increased vulnerability to new pathogens.

Validation of the iSperm for assessing rhinoceros Sperm

This study's objective was to determine the feasibility of using a portable computer-assisted sperm analyzer to standardize the evaluation of rhinoceros sperm motility and concentration. Assessments were performed opportunistically as part of other ongoing studies and included both fresh and cryopreserved samples from black (Diceros bicornis; n = 3), white (Ceratotherium simum; n = 7), and greater one-horned (Rhinoceros unicornis; n = 5) rhinoceroses. Accuracy of the iSperm Rhino 5 software in identifying sperm cells was evaluated through manual scoring of sperm tracks (n = 48 videos from 12 samples). The number of sperm identified by the observer and the software were significantly correlated (Pearson r = 0.9908, P < 0.0001). Moreover, the bias between the observer to iSperm values was small (Bland-Altman test; mean ratio = 0.97 observer/iSperm). A strong correlation (Pearson r = 0.9847, P < 0.0001) between hemocytometer counting and the iSperm for sperm concentration (n = 50) was also observed with a bias of just 1.03 (mean ratio hemocytometer to iSperm). Reliability analysis was performed by comparing ten consecutive evaluations on four different samples using intraclass correlation coefficients (ICC). In this study, the reliability (aka repeatability) of measuring the concentration or total motility via iSperm was deemed excellent (ICC > 0.96). Results of this work demonstrate that the iSperm offers a reliable and semi-automated alternative to manual evaluations for assessing sperm concentrations and motility in the rhinoceros. The ability to determine wildlife sperm concentrations rapidly and motility objectively while working under field conditions would be a great asset to conservation biologists in both zoological institutions and wildlife reserves.

Unravelling the diversity of Anaplasma species circulating in selected African wildlife hosts by targeted 16S microbiome analysis

Organisms in the genus Anaplasma are obligate intracellular alphaproteobacteria. Bovine anaplasmosis, predominantly caused by Anaplasma marginale, is the most prevalent tick-borne disease (TBD) of cattle worldwide. Other Anaplasma species are known to cause disease; these include A. ovis, A. platys in dogs, A. capra in goats and humans, and A. phagocytophilum in humans. The rapid advancement of next-generation sequencing technologies has led to the discovery of many novel sequences ascribed to the genus Anaplasma, with over 20 putative new species being proposed since the last formal organization of the genus. Most 16S rRNA gene surveys for Anaplasma were conducted on cattle and to a lesser extent on rodents, dogs, and ticks. Little is known about the occurrence, diversity, or impact of Anaplasma species circulating in wildlife species. Therefore, we conducted a 16S rRNA gene survey with the goal of identifying Anaplasma species in a variety of wildlife species in the Kruger National Park and neighbouring game reserves, using an unbiased 16S rRNA gene microbiome approach. An Anaplasma/Ehrlichia-group specific quantitative real-time PCR (qPCR) assay revealed the presence of Anaplasma and/or Ehrlichia species in 70.0% (21/30) of African buffalo, 86.7% (26/30) of impala, 36.7% (11/30) of greater kudu, 3.2% (1/31) of African wild dog, 40.6% (13/32) of Burchell's zebra, 43.3% (13/30) of warthog, 22.6% (7/31) of spotted hyena, 40.0% (12/30) of leopard, 17.6% (6/34) of lion, 16.7% (5/30) of African elephant and 8.6% (3/35) of white rhinoceros samples. Microbiome sequencing data from the qPCR positive samples revealed four 16S rRNA sequences identical to previously published Anaplasma sequences, as well as nine novel Anaplasma 16S genotypes. Our results reveal a greater diversity of putative Anaplasma species circulating in wildlife than currently classified within the genus. Our findings highlight a potential expansion of the Anaplasma host range and the need for more genetic information from other important genes or genome sequencing of putative novel species for correct classification and further assessment of their occurrence in wildlife, livestock and companion animals.

Genomic insights into southern white rhinoceros (Ceratotherium simum simum) reproduction: Revealing granulosa cell gene expression

In vivo-collected granulosa cells (GC) from the southern white rhinoceros (SWR) provide a non-invasive assessment of the developmental status of oocytes prior to in vitro culture, which could aid in the development of assisted reproductive technologies (ART). Our study aimed to investigate gene expression in SWR granulosa cells, collected in vivo and gain preliminary insight into the transcriptional activity occurring within the cells during various stages of oocyte development. It was hypothesized there would be similarities between the SWR GC transcriptome and cattle and humans, two species for which well-annotated genomes are available and ART are commonly used. GC were collected from SWR following ovum pickup (OPU) and pooled from all aspirated follicles. Total RNA was isolated, libraries prepared, and sequencing performed using an Illumina NextSeq 500. Reads were aligned and annotated to CerSimCot1.0. Databases for cattle and human were acquired for comparison. This study identified 37,407 transcripts present in GC of SWR. It was determined that cattle and human transcriptomes are valuable resources with a homology of 45 % with the SWR. In conclusion, these data provide preliminary, novel insights into the transcriptional activity of GC in the SWR that can be used to enhance ART in this species.

Aspects of white rhino movement over a 12-month period based on hourly GPS location data

Eight female southern white rhinos were monitored by ranger teams at the 64 km2 Ziwa Rhino Sanctuary (ZRS), Uganda, 24 hours per day, seven days per week for the year 1 May 2020–30 April 2021. The teams kept the monitored rhinos in view at all times, albeit from a safe distance. In bushier habitat, the rangers would be within 50 metres of the rhinos while in open habitat the rangers could be as much as 150 metres from them. Each ranger team had a smartphone installed with Cybertracker software. These were used to record various details of rhino behaviour including which sector and block the rhino had spent time in, and their GPS location; both on an hourly basis. Such detailed data for free ranging white rhinos has not been published before.

Building sustainable ecosystems through community education

Borana Conservancy lies in the Ewaso Nyiro ecosystem in Laikipia County, just north of the Equator in Kenya. Borana, together with its neighbour Lewa Wildlife Conservancy (LWC), is now home to 132 eastern black rhinos (Diceros bicornis michaeli) and 122 southern white rhinos (Ceratotherium simum simum). The population of black rhinos represents at least 13% of Kenya’s black rhino population. Borana’s work revolves around ‘the four Cs’: conservation, community, culture and commerce, showcasing best practices for sustainable living. The long-term goal of the Conservancy is to provide a sustainable ecosystem, in partnership with its neighbours and community, for critically endangered species on the brink of extinction. However, the survival of Borana’s rhinos and other wildlife, is threatened by the unsustainable utilization of natural resources and rangelands across Laikipia County. Expanding human populations are placing significant pressures on these rangelands, exacerbating years of over-utilization and poor management. According to Dr Dino Martins formerly of Mpala Research Centre in Laikipia, livestock stocking rates on many communally owned ranches and conservancies are estimated to be 50 times higher than the recommended ecological carrying capacity (ECC). Many of the current generation of pastoralists believe that the degraded rangelands in their landscape are normal, not realizing that the rangelands should be covered with grass that would retain moisture, sequester carbon, secure water sources, and support biodiversity, if properly utilized and the livestock carrying capacity were reduced to the ideal balance. Although the local schools teach theoretical environmental science, there is no exposure, at a practical level, to how essential intact, functioning ecosystems serve for both humanity and biodiversity. There is an increasing acknowledgement of the value of targeted, practical conservation education programmes in helping communities living adjacent to protected areas (PAs) to develop sustainable livelihoods and allow the effective, long-term conservation of wildlife and ecosystems. The future of Borana Conservancy, and of all PAs across Laikipia, Kenya and Africa as a whole, will depend on people placing a high natural-capital value on conservation and wildlife habitats, and on their having the skills to manage the wider environment in ways that support both human livelihoods and wildlife.

Ultra-performance convergence chromatography tandem mass spectrometry analysis of adrenal and gonadal steroid hormones in southern white rhinoceros (Ceratotherium simum simum) faeces and serum

Steroid hormone analysis is routinely undertaken in the assessment of stress response and reproductive function in the management of both captive and free-ranging wildlife species. Faecal samples have become the preferred sample type for analysis as collection is non-invasive and easily assessable. These investigations are generally aimed at aiding successful translocations, enhanced survival outcomes in captivity and improvement of reproductive rate. Immunoassays are the most common approach in the analysis of hormones, particularly in the case of the southern white rhinoceros (Ceratotherium simum simum). Non-specificity, attributed to structural similarity of steroid metabolites impedes accurate evaluations which can be eliminated by chromatographic techniques which are more specific, selective and provide comprehensive analyses.This study developed and validated three methods using ultra-performance convergence chromatography tandem mass spectrometry for the assessment of classical androgens, progestogens and adrenal steroids, as well as the C11-oxy androgens and C11-oxy progestogens in serum and faeces from white rhinoceros. The limit of detection and quantification were determined for each steroid, parameters such as accuracy (<19.8 % RSD) and precision (<20.2 % RSD) were established with recovery, matrix effect, and process efficiency within acceptable limits. Subsequent analysis of serum and faecal samples from five white rhinoceros identified novel steroids for the first time in this species. In addition to the classical adrenal steroids, the following C11-oxy steroids were detected in faecal samples: 11α-hydroxydihydroprogesterone (168 ng/g), 11α-hydroxyprogesterone (125.9 ng/g), 11β-hydroxyprogesterone (210.2 ng/g) and 11-ketoandrostenedione (3.3–19.6 ng/g) with 11-deoxycortisol being the major glucocorticoid (24.2–67.3 ng/g) together with 21-deoxycortisone (40.7 ng/g) and deoxycorticosterone (7.6–14.6 ng/g). In serum samples 11β-hydroxyandrostenedione (0.35–2.34 ng/mL) and 11β-hydroxytestosterone (0.18–1.62 ng/mL) were the predominant androgens with cortisol (5.8–20.5 ng/mL), the predominant glucocorticoid, while corticosterone, 18-hydroxycorticosterone and aldosterone were also detected.These methods can be applied independently to assess either androgens, progestogens, or adrenal steroid panels or in combination to assess the cohort of gonadal and adrenal steroids in faeces and/or serum, in southern white rhinoceros as well as other wildlife species. Analysis would enable the accurate assessment of reproductive health and stress responses while also distinguishing between stress and distress thus contributing to the conservation of wildlife species.

Robust induction of primordial germ cells of white rhinoceros on the brink of extinction

In vitro gametogenesis, the process of generating gametes from pluripotent cells in culture, is a powerful tool for improving our understanding of germ cell development and an alternative source of gametes. Here, we induced primordial germ cell-like cells (PGCLCs) from pluripotent stem cells of the northern white rhinoceros (NWR), a species for which only two females remain, and southern white rhinoceros (SWR), the closest species to the NWR. PGCLC differentiation from SWR embryonic stem cells is highly reliant on bone morphogenetic protein and WNT signals. Genetic analysis revealed that SRY-box transcription factor 17 (SOX17) is essential for SWR-PGCLC induction. Under the defined condition, NWR induced pluripotent stem cells differentiated into PGCLCs. We also identified cell surface markers, CD9 and Integrin subunit alpha 6 (ITGA6), that enabled us to isolate PGCLCs without genetic alteration in pluripotent stem cells. This study provides a first step toward the production of NWR gametes in culture and understanding of the basic mechanism of primordial germ cell specification in a large animal.

Application of decision tools to ethical analysis in biodiversity conservation.

Achieving ethically responsible decisions is crucial for the success of biodiversity conservation projects. We adapted the ethical matrix, decision tree, and Bateson's cube to assist in the ethical analysis of complex conservation scenarios by structuring these tools so that they can implement the different value dimensions (environmental, social, and animal welfare) involved in conservation ethics. We then applied them to a case study relative to the decision-making process regarding whether or not to continue collecting biomaterial on the oldest of the two remaining northern white rhinoceroses (Ceratotherium simum cottoni), a functionally extinct subspecies of the white rhinoceros. We used the ethical matrix to gather ethical pros and cons and as a starting point for a participatory approach to ethical decision-making. We used decision trees to compare the different options at stake on the basis of a set of ethical desiderata. We used Bateson's cube to establish a threshold of ethical acceptability and model the results of a simple survey. The application of these tools proved to be pivotal in structuring the decision-making process and in helping reach a shared, reasoned, and transparent decision on the best option from an ethical point of view among those available.