Successful acclimatization of mandrills (Mandrillus sphinx) translocated to Conkouati-Douli National Park, Republic of Congo, as measured by fecal glucocorticoid metabolites

Translocation and reintroduction are common tools in conservation management and can be very successful. However, translocation can be stressful for the animals involved, and stress is implicated as a major cause of failure in release programs. Conservation managers should therefore seek to understand how the stages of translocation impact stress physiology in the animals involved. We quantified fecal glucocorticoid metabolites (fGCMs) as a noninvasive measure of response to potential stressors during a translocation of 15 mandrills (Mandrillus sphinx) into Conkouati-Douli National Park, Republic of Congo. The mandrills were initially housed in a sanctuary, transferred to a pre-release enclosure in the National Park and then released into the forest. We collected repeated fecal samples (n = 1101) from known individuals and quantified fGCMs using a previously validated enzyme immunoassay. Transfer from the sanctuary to the pre-release enclosure correlated with a significant 1.93-fold increase in fGCMs, suggesting that transfer was a stressor for the mandrills. fGCM values decreased over time in the pre-release enclosure, suggesting that the mandrills recovered from the transfer and acclimatized to the enclosure. Release to the forest was not linked to a significant increase in fGCMs over the final values in the enclosure. Following release, fGCMs continued to decrease, fell below sanctuary values after just over a month and were about half the sanctuary values after 1 year. Overall, our results suggest that the translocation, although initially presenting a physiological challenge to the animals, was not detrimental to the well-being of the animals over the timescale of the study and, in fact, may have been beneficial. Our findings show the value of non-invasive physiology in monitoring, evaluating and designing wildlife translocations and, ultimately, contributing to their success.

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.

EFFECT OF BOMA CONFINEMENT ON HEMATOLOGIC AND BIOCHEMICAL VALUES IN FREE-RANGING WHITE RHINOCEROS (CERATOTHERIUM SIMUM) IN KRUGER NATIONAL PARK, SOUTH AFRICA

Boma adaptation is an important component of rhinoceros translocations to allow transition to new diets, restricted space, and quarantine for disease screening. However, up to 20% of recently captured white rhinoceros (Ceratotherium simum) do not adjust to captivity, resulting in early release or even death. The causes and physiologic consequences of maladaptation to boma confinement are poorly understood. The aim of this investigation was to evaluate hematologic and serum biochemical changes in maladapted rhinoceros compared to animals that adapted under the same boma conditions. Ninety-six white rhinoceros were captured between 2009 and 2011 in Kruger National Park, South Africa and placed in bomas prior to translocation. Weight, complete blood count, and serum biochemical panel results were recorded when rhinoceros were placed in the boma and repeated on the day of release. In this study, the mean duration of boma confinement for maladapted white rhinoceros was 13 d (range 8-16 d) compared to 89.9 d (range 39-187 d) for adapted animals. Mean weight loss between capture and release was significantly greater in maladapted rhinoceros (224.0 versus 65.9 kgs; P<0.001). Although adapted rhinoceros had statistically significant changes in some hematologic and biochemical values, most were not considered clinically relevant. In contrast, the maladapted rhinoceros had significant changes at the time of early release from the boma, including evidence of leukocytosis with left shift, lymphopenia, eosinopenia, decreased red blood cell count and hematocrit, increased serum creatine kinase, and decreased serum calcium, phosphorus, and magnesium values. Along with loss of body condition, these findings were consistent with a stress-associated catabolic response. These changes occurred in the first 2 wk of confinement, and the results provide a foundation for evaluating adaptation in white rhinoceros. Future studies should focus on factors that improve adaptation and welfare of recently confined free-ranging white rhinoceros.

Preliminary Findings on How Different Management Systems and Social Interactions Influence Fecal Glucocorticoid Metabolites in White Rhinoceros (Ceratotherium simum)

Simple Summary

In recent years, interest in improving the welfare of wild species in captivity has grown. The aim of this investigation was to evaluate the effects of different social environments and management systems on the cortisol secretion of fourteen white rhinoceroses (Ceratotherium simum) living under different conditions by using use noninvasive methods. The fecal glucocorticoid metabolite secretion was found to be affected by both management systems and social interactions. Additionally, sex is another factor that seems to influence. This research provides a deeper understanding of glucocorticoid production in white rhinoceroses, but more studies are needed to fully understand its influence on reproductive biology.

Abstract

White rhinoceroses (Ceratotherium simum) are the most social and gregarious species of all rhinoceroses known worldwide. One of the most critical effects of elevated glucocorticoid concentrations, especially in threatened species, is its relation to chronic stress, which could potentially lead to immunosuppression and reduced reproductive activity. Our aim is to determine how different social environments and management systems might be influencing the secretion of fecal glucocorticoids in white rhinoceroses. We have analyzed the concentration of fecal glucocorticoid metabolites in 658 fecal samples from 14 white rhinoceroses, seven free-ranging rhinos, and seven rhinos from two different managed captive populations. HPLC techniques were used to determine the main glucocorticoid metabolite found in this species, and a competitive EIA was used to establish fecal 5α-pregnan-3 3β, 11β, 21-triol-20-oneglucocorticoid metabolite (fGCM) levels. Our results reveal that management systems and social interactions had an influence on fGCM levels, suggesting that the more restrictive the management and social conditions are, the higher the glucocorticoid concentrations that are found. Additionally, sex was also found to influence fGCM levels, as in females, fGCM concentrations were higher than in males. We conclude that the analysis of glucocorticoids in relation to other factors is a powerful tool to assess adrenocortical response in white rhinoceros in order to broaden the knowledge of their reproductive biology and improve the management of the species.

CHALLENGES TO ANIMAL WELFARE DURING TRANSPORTATION OF WILD MAMMALS: A REVIEW (1990-2020)

Wild mammal transport is an important component of conservation translocation as well as the economic wildlife trade. This article reviews the physiological responses to transport that have been measured in wild mammalian species, factors associated with these responses, and interventions that have been applied to mitigate these responses. By organizing the literature review along the "five domains model" of animal welfare, namely, the physical-functional domains (nutrition, environment, health, behavior) and the mental domain (mental state), it can be demonstrated that wild mammal transport is associated with challenges to ensuring positive animal welfare in all five domains. Transported wild mammals can experience dehydration, catabolism, fatigue, immunosuppression, behavioral changes, and stress. Factors influencing these physiological responses to transport have only been researched in a few studies encompassing species, journey length, ambient temperature, vehicle motion, stocking density, orientation, habituation, vehicle speed allowance, and road type. The administration of tranquilizers has been shown to mitigate negative physiological responses to transport. There is a need to further investigate species and situation-specific physiological responses to transport and factors associated with these responses in order to identify challenges to ensuring animal welfare and improving translocation success.

Effects of Chronic Stress on the Fecal Microbiome of Malayan Pangolins (Manis javanica) Rescued from the Illegal Wildlife Trade

Pangolins (scaly anteaters, Pholidota) are among those mammals that are most affected by the international, illegal wildlife trade. Recently, wildlife rescue centers in China became dedicated to rehabilitate confiscated pangolins and prepare them for reintroduction to the wild. Chronic stress is thought to be the main reason for a disturbed microbiota community and a higher mortality rate of pangolin in captivity. In this study, we compared the cortisol levels and the fecal microbiome of Malayan pangolin (Manis javanica) born and reared in captivity (PCB; n = 7) with those rescued from the wildlife trade (PCT; n = 16). Results show that the level of cortisol in PCT was significantly lower than that observed in PCB. There were also significant differences in the composition of the fecal microflora between the two groups, and the diversity of intestinal microbiota was higher in PCB than in PCT. At the phylum level, the bacteria with significant difference between the two groups included Firmicutes and Bacteroides. At the genus level, bacteria such as Bacteroides, Parabacterides, and Clostridium showed significant differences between the two groups. This study proves that chronic stress has a considerable effect on the diversity and composition of fecal microbiota in Malayan pangolin.

Negligible hormonal response following dehorning in free-ranging white rhinoceros (Ceratotherium simum)

The white rhinoceros (Ceratotherium simum) is experiencing unsustainable poaching losses fuelled by a demand for horn. Increasingly, private and state reserves are dehorning their rhinoceros populations in an attempt to reduce poaching pressure. Rhinoceroses use their horns in social interactions as well as during resource access and so its partial removal as part of reserve management practices may adversely influence these behaviours. Physiological stress can correlate with animal welfare, reproductive state and health and thus acts as a useful indicator of these parameters. To establish whether dehorning causes a physiological stress response, glucocorticoid and gonadal steroid profiles of free-ranging white rhinoceroses were determined through the collection and analysis of faecal steroid metabolites before and after dehorning. Faecal corticoid profiles were not influenced by the number of occasions a rhinoceros had been dehorned or by the number of days that had elapsed since dehorning. Furthermore, there was no apparent suppression in the concentrations of testosterone or progesterone metabolites in males and females, respectively, after exposure to multiple dehorning procedures. These findings should increase wildlife managers' confidence that dehorning does not negatively impact white rhinoceros physiology as measured hormonally.

Factors driving the discovery and utilization of a newly available area by African elephants

For large mammals, area expansion is a key conservation measure to prevent species’ decline and extinction. Yet, its success depends on whether animals discover and later use these areas. Here, using GPS data, we investigated how herds of elephants detected and used an area made available to them after the removal of a fence. We studied the elephants’ behaviour before and after the fence removal, accounting for seasonal changes in movement patterns. In contrast to previous studies, herds visited the newly available area within a month of the fence removal, and the maximum distance they moved into the new area was reached between 5 and 9 months after the fence removal. Yet, elephants did not preferentially visit the new area at night. By the second year, all herds had shifted their seasonal home ranges and incorporated the new area, in contrast to a previous range expansion event. Our analyses show that the regular proximity of elephants to the original fence, and the fact that the new area was generally composed of preferred habitats of the elephants, probably explained the rapid discovery and use of the area. Our study improves our understanding of animal exploration and the role of habitat quality, and thus may improve range expansion and corridor programmes.

A Ten-Stage Protocol for Assessing the Welfare of Individual Non-Captive Wild Animals: Free-Roaming Horses (Equus Ferus Caballus) as an Example

Knowledge of the welfare status of wild animals is vital for informing debates about the ways in which we interact with wild animals and their habitats. Currently, there is no published information about how to scientifically assess the welfare of free-roaming wild animals during their normal day-to-day lives. Using free-roaming horses as an example, we describe a ten-stage protocol for systematically and scientifically assessing the welfare of individual non-captive wild animals. The protocol starts by emphasising the importance of readers having an understanding of animal welfare in a conservation context and also of the Five Domains Model for assessing welfare. It goes on to detail what species-specific information is required to assess welfare, how to identify measurable and observable indicators of animals' physical states and how to identify which individuals are being assessed. Further, it addresses how to select appropriate methods for measuring/observing physical indicators of welfare, the scientific validation of these indicators and then the grading of animals' welfare states, along with assigning a confidence score. Finally, grading future welfare risks and how these can guide management decisions is discussed. Applying this ten-stage protocol will enable biologists to scientifically assess the welfare of wild animals and should lead to significant advances in the field of wild animal welfare.

Chronic captivity stress in wild animals is highly species-specific

Wild animals are brought into captivity for many reasons-conservation, research, agriculture and the exotic pet trade. While the physical needs of animals are met in captivity, the conditions of confinement and exposure to humans can result in physiological stress. The stress response consists of the suite of hormonal and physiological reactions to help an animal survive potentially harmful stimuli. The adrenomedullary response results in increased heart rate and muscle tone (among other effects); elevated glucocorticoid (GC) hormones help to direct resources towards immediate survival. While these responses are adaptive, overexposure to stress can cause physiological problems, such as weight loss, changes to the immune system and decreased reproductive capacity. Many people who work with wild animals in captivity assume that they will eventually adjust to their new circumstances. However, captivity may have long-term or permanent impacts on physiology if the stress response is chronically activated. We reviewed the literature on the effects of introduction to captivity in wild-caught individuals on the physiological systems impacted by stress, particularly weight changes, GC regulation, adrenomedullary regulation and the immune and reproductive systems. This paper did not review studies on captive-born animals. Adjustment to captivity has been reported for some physiological systems in some species. However, for many species, permanent alterations to physiology may occur with captivity. For example, captive animals may have elevated GCs and/or reduced reproductive capacity compared to free-living animals even after months in captivity. Full adjustment to captivity may occur only in some species, and may be dependent on time of year or other variables. We discuss some of the methods that can be used to reduce chronic captivity stress.

"Feelings and Fitness" Not "Feelings or Fitness"-The Raison d'être of Conservation Welfare, Which Aligns Conservation and Animal Welfare Objectives

Increasingly, human activities, including those aimed at conserving species and ecosystems (conservation activities) influence not only the survival and fitness but also the welfare of wild animals. Animal welfare relates to how an animal is experiencing its life and encompasses both its physical and mental states. While conservation biology and animal welfare science are both multi-disciplinary fields that use scientific methods to address concerns about animals, their focus and objectives sometimes appear to conflict. However, activities impacting detrimentally on the welfare of individual animals also hamper achievement of some conservation goals, and societal acceptance is imperative to the continuation of conservation activities. Thus, the best outcomes for both disciplines will be achieved through collaboration and knowledge-sharing. Despite this recognition, cross-disciplinary information-sharing and collaborative research and practice in conservation are still rare, with the exception of the zoo context. This paper summarizes key points developed by a group of conservation and animal welfare scientists discussing scientific assessment of wild animal welfare and barriers to progress. The dominant theme emerging was the need for a common language to facilitate cross-disciplinary progress in understanding and safeguarding the welfare of animals of wild species. Current conceptions of welfare implicit in conservation science, based mainly on "fitness" (physical states), need to be aligned with contemporary animal welfare science concepts which emphasize the dynamic integration of "fitness" and "feelings" (mental experiences) to holistically understand animals' welfare states. The way in which animal welfare is characterized influences the way it is evaluated and the emphasis put on different features of welfare, as well as, the importance placed on the outcomes of such evaluations and how that information is used, for example in policy development and decision-making. Salient examples from the New Zealand and Australian context are presented to illustrate. To genuinely progress our understanding and evaluation of wild animal welfare and optimize the aims of both scientific disciplines, conservation and animal welfare scientists should work together to evolve and apply a common understanding of welfare. To facilitate this, we propose the formal development of a new discipline, Conservation Welfare, integrating the expertise of scientists from both fields.

Expanding the actions of cortisol and corticosterone in wild vertebrates: A necessary step to overcome the emerging challenges

We conducted a review of scientific articles published between 2000 and 2014 and evaluated how frequently various aspects of cortisol and corticosterone (CORT) actions have been considered in studies on wild vertebrates. Results show that (1) the notion that CORT are stress-responsive hormones is central in our theoretical frameworks and it is reflected by the fact that several articles refer to CORT as "stress hormones". (2) The large majority of studies do not contemplate the possibility of decrease and no change in CORT levels in response to chronic stressors. (3) Our ideas about CORT actions on energy balance are slanted towards the mobilization of energy, though there are several studies considering -and empirically addressing- CORT's orexigenic actions, particularly in birds. (4) The roles of CORT in mineral-water balance, though widely documented in the biomedical area, are virtually ignored in the literature about wild vertebrates, with the exception of studies in fish. (5) Adrenocorticotropic hormone (ACTH) independent regulation of CORT secretion is also very scarcely considered. (6) The preparative, permissive, suppressive and stimulatory actions of CORT, as described by Sapolsky et al. (2000), are not currently considered by the large majority of authors. We include an extension of the Preparative Hypothesis, proposing that the priming effects of baseline and stress-induced CORT levels increase the threshold of severity necessary for subsequent stimuli to become stressors. Studies on animal ecology and conservation require integration with novel aspects of CORT actions and perspectives developed in other research areas.

Experimental evidence for homeostatic sex allocation after sex-biased reintroductions

First principles predict negative frequency-dependent sex allocation, but it is unproven in field studies and seldom considered, despite far-reaching consequences for theory and practice in population genetics and dynamics as well as animal ecology and behaviour. Twenty-four years of rhinoceros calving after 45 reintroductions across southern Africa provide the first in situ experimental evidence that unbalanced operational sex ratios predicted offspring sex and offspring sex ratios. Our understanding of population dynamics, especially reintroduction and invasion biology, will be significantly impacted by these findings.

A SCORING SYSTEM TO IMPROVE DECISION MAKING AND OUTCOMES IN THE ADAPTATION OF RECENTLY CAPTURED WHITE RHINOCEROSES (CERATOTHERIUM SIMUM) TO CAPTIVITY

Ninety-four subadult and adult white rhinoceroses (Ceratotherium simum) were captured between February and October, 2009-11, in Kruger National Park and placed in holding bomas prior to translocation to other locations within South Africa. A simple three-category system was developed based on appetite, fecal consistency/volume, and behavior to assess adaptation to bomas. Individual animal and group daily median scores were used to determine trends and when rhinoceroses had successfully adapted to the boma. Seventeen rhinoceroses did not adapt to boma confinement, and 16 were released (1 mortality). No differences in boma scores were observed between rhinoceroses that adapted and those that did not, until day 8, when the first significant differences were observed (adapted score=13 versus nonadapted score=10). The time to reach a boma score determined as successful adaptation (median 19 d) matched subjective observations, which was approximately 3 wk for most rhinoceroses. Unsuccessful adaptation was indicated by an individual boma score of less than 15, typically during the first 2 wk, or a declining trend in scores within the first 7-14 d. This scoring system can be used for most locations and could also be easily adapted to other areas in which rhinoceroses are held in captivity. This tool also provides important information for assessing welfare in newly captured rhinoceroses.

Investigating temporary acyclicity in a captive group of Asian elephants (Elephas maximus): Relationship between management, adrenal activity and social factors

Routine faecal steroid monitoring has been used to aid the management of five captive Asian elephant (Elephas maximus) females at Chester Zoo, UK, since 2007. Progestagen analysis initially revealed synchronised oestrous cycles among all females. However, a 14- to 20-week period of temporary acyclicity subsequently occurred in three females, following several management changes (increased training, foot-care and intermittent matriarch removal for health reasons) and the initiation of pregnancy in another female. The aim of this study was to retrospectively investigate whether these management changes were related to increased adrenal activity and disruption of ovarian activity, or whether social factors may have been involved in the temporary cessation of cyclicity. Faecal samples collected every other day were analysed to investigate whether glucocorticoid metabolites were related to reproductive status (pregnant, cycling, acyclic) or management (training, foot-care, matriarch presence). Routine training and foot-care were not associated with adrenal activity; however, intensive foot-care to treat an abscess in one female was associated with increased glucocorticoid concentration. Matriarch presence influenced adrenal activity in three females, being lower when the matriarch was separated from the group at night compared to being always present. However, in the females that exhibited temporary acyclicity, there was no consistent relationship between glucocorticoids and cyclicity state. Although the results of this study do not fully explain this occurrence, the highly synchronised nature of oestrous cycles within this group, and the concurrent acyclicity in three females, raises the question of whether social factors could have been involved in the temporary disruption of ovarian activity.

Motile Sperm Output by Male Cheetahs (Acinonyx jubatus) Managed Ex Situ Is Influenced by Public Exposure and Number of Care-Givers

The collective cheetah (Acinonyx jubatus) population in zoological institutions has never been self-sustaining because of challenges in natural reproduction. A retrospective analysis of North American zoo-breeding records has revealed that >90% of litters produced since 2003 occurred in facilities ‘off-display’ from the public. We examined seminal, endocrine, and behavioral traits of 29 adult male cheetahs that were: 1) managed in public exhibit or off-display facilities; 2) maintained by different numbers of cheetah-specific care-givers; and 3) living adjacent to varying numbers of adult conspecifics. Cheetahs housed off-display produced more total motile sperm/ejaculate (P = 0.04) than on-exhibit males. This finding was mirrored in our laboratory’s historical records where two-fold more total motile sperm (P < 0.01) were measured in ejaculates from individuals with no public exposure (n = 43) compared to on-exhibit (n = 116) counterparts. Males at institutions with ≤3 care-givers also produced more total motile sperm/ejaculate (P < 0.03) and spent more time behaviorally active (P < 0.01) than at facilities using >3 care-givers. Exposure to high numbers of conspecifics within the same institution did not impact (P > 0.05) seminal traits, and presence of the public, care-giver number, or animals/facility had no influence (P > 0.05) on androgen or glucocorticoid excretion or other behavioral metrics. Findings indicate that male cheetahs are sensitive to general public exposure and too many care-givers, resulting in compromised motile sperm output/ejaculate with mechanism of action unrelated to altered androgen or glucocorticoid excretion.

The effect of pre-release captivity on post-release performance in reintroduced eastern bettongs Bettongia gaimardi

Reintroductions are used to re-establish populations of species within their indigenous range, but their outcomes are variable. A key decision when developing a reintroduction strategy is whether to include a temporary period of confinement prior to release. Pre-release confinement is primarily used for the purpose of quarantine or as a delayed-release tactic to influence the performance or behaviour of founders post-release. A common difference between these approaches is that quarantine tends to be conducted in ex situ captivity, whereas delayed releases tend to involve in situ confinement at the release site. Although these practices are commonly viewed independently, it may be possible for a single confinement period to be used for both purposes. We tested whether temporarily holding wild eastern bettongs Bettongia gaimardi in ex situ captivity for 95–345 days prior to release (delayed release) influenced their body mass, pouch occupancy or survival during the first 1.5 years post-release, compared to founders released without confinement (immediate release). Our results suggest that exposing founders to captivity did not alter their body mass or performance post-release, despite being heavier and having fewer pouch young when released. We conclude that, for this species, ex situ captivity does not represent a tactical opportunity to improve post-release performance but can be used for quarantine without affecting the probability of establishment.

Seasonal patterns of hormones, macroparasites, and microparasites in wild African ungulates: the interplay among stress, reproduction, and disease

Sex hormones, reproductive status, and pathogen load all affect stress. Together with stress, these factors can modulate the immune system and affect disease incidence. Thus, it is important to concurrently measure these factors, along with their seasonal fluctuations, to better understand their complex interactions. Using steroid hormone metabolites from fecal samples, we examined seasonal correlations among zebra and springbok stress, reproduction, gastrointestinal (GI) parasite infections, and anthrax infection signatures in zebra and springbok in Etosha National Park (ENP), Namibia, and found strong seasonal effects. Infection intensities of all three GI macroparasites examined (strongyle helminths, Strongyloides helminths, and Eimeria coccidia) were highest in the wet season, concurrent with the timing of anthrax outbreaks. Parasites also declined with increased acquired immune responses. We found hormonal evidence that both mares and ewes are overwhelmingly seasonal breeders in ENP, and that reproductive hormones are correlated with immunosuppression and higher susceptibility to GI parasite infections. Stress hormones largely peak in the dry season, particularly in zebra, when parasite infection intensities are lowest, and are most strongly correlated with host mid-gestation rather than with parasite infection intensity. Given the evidence that GI parasites can cause host pathology, immunomodulation, and immunosuppression, their persistence in ENP hosts without inducing chronic stress responses supports the hypothesis that hosts are tolerant of their parasites. Such tolerance would help to explain the ubiquity of these organisms in ENP herbivores, even in the face of their potential immunomodulatory trade-offs with anti-anthrax immunity.

Effects of crowding and sex on fecal cortisol levels of captive forest musk deer

BACKGROUND

Restricted space and close contact with conspecifics in captivity may be stressful for musk deer, as they are highly territorial and solitary in the wild. So we tested the effects of crowding on stress of forest musk deer (Moschus berezovskii) in heterosexual groups, using fecal cortisol analysis as a non-invasive method. 32 healthy adults during non-breeding seasons were chose as our experimental objects. Group 1 was defined as higher crowding condition, with 10-15 m2/deer (6 enclosures, 10♀ and 6♂); group 2 was defined as lower crowding condition, with 23-33 m2/deer (6 enclosures, 10♀ and 6♂). Every enclosure contained 1 male and 3 female. These patterns had been existed for years.

RESULTS

The results showed that females in lower crowding condition (217.1 ± 9.5 ug/g) had significantly higher fecal cortisol levels than those in higher crowding condition (177.2 ± 12.1 ug/g). Interestingly, crowding seemed have no effect on male fecal cortisol levels (148.1 ± 9.1 ug/g and 140.5 ± 13.3 ug/g, respectively). At both groups, cortisol was significantly lower in males than in females.

CONCLUSIONS

These results showed that chronic crowding may affect stress status of captive forest musk deer. The captive environment should consider the space need for musk deer.

Effects of management strategies on glucocorticoids and behavior in Indian rhinoceros (Rhinoceros unicornis): translocation and operant conditioning

The ex situ Indian rhino population experienced a decrease in genetic diversity indicating that the breeding program could possibly benefit from novel reproductive management strategies to ensure population sustainability. We sought to determine how management tools used for reproductive management, specifically translocation and operant conditioning, impact physiological and behavioral measures of welfare in Indian rhinos. First, an adrenocorticotropic hormone challenge performed in an adult male resulted in a 38-fold increase in urinary and a 3.5-fold increase in fecal glucocorticoid metabolites (FGM). Mean and peak FGM differed among three females, but all demonstrated elevated (P < 0.0001) concentrations for variable durations after translocation that lasted up to 9 weeks. Lastly, behavioral and adrenal responses of two females to operant conditioning to stand during transrectal ultrasound exams were monitored and rhinos differed in their mean and peak FGM concentrations. However, FGM were not different before versus during training or on pasture versus in the barn. One female exhibited more stereotypic behavior during training in the barn than on pasture (P < 0.05); although, stereotypies (1.73% of time) were relatively uncommon overall. In summary, individual variation exists in FGM both at baseline levels and in response to a stressor. In addition, while a transient rise in glucocorticoid activity post-translocation indicated that Indian rhinos have a physiological response to changes in their environment, minor alterations in daily routines using operant conditioning only resulted in minimal changes in behaviors and FGM.

Impacts of environmental pressures on the reproductive physiology of subpopulations of black rhinoceros (Diceros bicornis bicornis) in Addo Elephant National Park, South Africa

Black rhinoceros are an icon for international conservation, yet little is known about their physiology due to their secretive nature. To overcome these challenges, non-invasive methods were used to monitor rhinoceros in two sections of Addo Elephant National Park, South Africa, namely Addo and Nyathi. These sections were separated by a public road, and the numbers of elephants, predators and tourists were higher in Addo. Faecal samples (n = 231) were collected (from July 2007 to November 2010) from known individuals and analysed for progestagen and androgen metabolite (FPM and FAM, respectively) concentrations. As biotic factors could impact reproduction, we predicted that demographics, FPM and FAM would vary between sections and with respect to season (calendar and wet/dry), climate and age of the rhinoceros. Mean FPM concentrations from pregnant females were seven times higher (P < 0.05) than samples from non-pregnant rhinoceros. Positive relationships were found between monthly temperatures and FPM from non-pregnant females (r (2) = 0.25, P = 0.03) and the percentage of calves born (r = 0.609, P = 0.04). Although FAM peaked in the spring, when the majority of calves (40%) were conceived, no seasonal patterns in male androgen concentrations were found with respect to month of conception and parturition. Females in Addo had a longer inter-calving interval and were less likely to be pregnant (P < 0.05) compared with those in Nyathi. The biotic stressors (e.g. predators and more competitors) within Addo section could be affecting the reproductive physiology of the rhinoceros negatively. Enhanced knowledge about how black rhinoceros populations respond to environmental stressors could guide management strategies for improving reproduction.

Glucocorticoid response to changes in enclosure size and human proximity in the Persian onager (Equus hemionus onager)

This study investigated glucocorticoid (GC) responses to season and changes in enclosure size and human proximity in the Persian onager (Equus hemionus onager). Enzyme immunoassays were validated to measure GC metabolites in urine and feces (fGCM). Fecal samples were collected from 10 female onagers while in a large pasture, after transport to smaller yards (in greater proximity to people), and 2 months thereafter. Urine samples were collected for 1 year while females were in smaller yards to examine seasonal GC activity. Approximately, 2-fold increases (P < 0.05) were observed in fGCM levels after transport from pasture to yards with increased human exposure, followed by a rapid decline (within -17 days) to baseline (pasture) values. However, responses varied among onagers during the 30 days after translocation, with one female failing to acclimate. Mean fGCM concentrations in smaller yards 2 months after transport were comparable to those in pasture. Seasonal GC concentrations were lowest (P < 0.05) during winter, indicating modest seasonal variability. Results demonstrate an acute increase in GC secretion in Persian onagers that moved from large to small enclosures coincident with increased human activities. Most animals acclimated within 3 weeks, suggesting that this rare equid has retained mechanisms to acclimate to marked alterations in an ex situ environment.