Captive Elephants Research Articles

Personality and behaviour of three captive African savannah elephants (Loxodonta africana)

This study explores the diversity in individual response for three captive African Savannah Ele-phants (Loxodonta africana) to variations in the daily number of zoo visitors. The nocturnal behav-iour of the elephants was observed in two periods with a factor 5.1 difference in numbers of zoo visitors. Ten behavioural expressions for each elephant were compared for the two periods. Data was collected with surveillance cameras for ten hours (20:00 to 06:00) throughout six nights. Fur-thermore, the data was compared to a similar study on the same elephants performed two years earlier. Both studies revealed a significant difference in behaviour between low activity and high visitor activity periods for all three elephants in the behaviour ’Walk’. No overall significant differ-ence was found in the other behavioural expressions. Clear difference in reaction norms was found between the matriarch and the two subordinates for the behaviours: ’Feed from ground’, ’Inactive’, ’Walk’ and ’Other’. This study shows that elephants in captivity are influenced by an increase in the number of zoo visitors, and that the personality or social status of the elephant may provide them with different resilience to disturbance.

Elephantoloemus indicus Austen, 1930 (Diptera: Calliphoridae) as the cause of cutaneous myiasis in captive Indian elephants from Assam, India.

Elephantoloemus indicus Austen, 1930, a dipteran calliphorid fly is known to cause by its larval stage obligatory cutaneous myiasis in Indian subspecies of Asian elephants (Elephas maximus indicus Cuvier, 1798) in Myanmar and Thailand. The present study was undertaken on morphological identification of some specimens of fly larvae which were recovered from the warbles detected on the skin of captive Indian elephants at the Nameri National Park and Kaziranga National Park both situated in the state of Assam, India. The larval specimens were whitish to creamy white in colour and body conformation varied from cylindrical to barrel shaped depending on their measured size (Av 6.12±0.28×2.35±0.12mm). Microscopic examination of processed larvae revealed presence of numerous single pointed spines uniformly distributed on entire body surface, well developed mouth hooks and cephalopharyngeal skeleton at the anterior end and posterior spiracles each with lightly sclerotized peritreme enclosing three short and straight respiratory slits. Based on geographical distribution of the fly, host relation, larval parasitism and morphological characters, the larvae were determined as of the genus Elephantoloemus which is represented by E. indicus as the only species described so far. This finding seems to be the first record in India after its report from Myanmar and Thailand.

First study on the effect of transforming growth factor beta 1 and insulin-like growth factor 1 on the chondrogenesis of elephant articular chondrocytes in a scaffold-based 3D culture model.

Background and Aim:Osteoarthritis (OA) is recognized as a degenerative joint disease that leads to chronic pain and low quality of life in animals. Captive elephants, the largest land mammals with a long lifespan, are more prone to develop OA due to restricted spaces and insufficient physical activity. This study aimed to investigate the effect of transforming growth factor-β1 (TGF-β1) and insulin-like growth factor 1 (IGF-1) on elephant chondrogenesis in a scaffold culture of articular chondrocytes.Materials and Methods:Elephant chondrocytes-seeded gelatin scaffolds were cultured in chondrogenic media with or without 10 ng/mL of TGF-β1 or IGF-1 alone or 5–10 ng/mL of their combination for up to 21 days. The mRNA expression of cartilage-specific anabolic genes, ACAN and COL2A1, was analyzed using a real-time reverse transcription-polymerase chain reaction. The amounts of sulfated glycosaminoglycans (sGAGs) in conditioned media and contents in cultured scaffolds were determined through dimethylmethylene blue assay. Cell morphology, accumulation of proteoglycans, and details of the cultured scaffolds were determined using hematoxylin-eosin staining, safranin O staining, and scanning electron microscopy (SEM), respectively.Results:TGF-β1 alone significantly upregulated ACAN gene expression but not COL2A1, while IGF-1 alone did not enhance both ACAN and COL2A1 genes. The combination significantly upregulated both mRNA expression levels of ACAN and COL2A1 gene at day 14. The sGAGs accumulation and contents in the treatment groups, except IGF-1 tended to be higher than the controls, concomitantly with the production of the extracellular matrix, showed the formation of a cartilage-like tissue through histological and SEM analyses.Conclusion:Together, our results suggest that the single treatment of TGF-β1 has a selective effect on ACAN gene, while the combined growth factors seem to be an advantage on elephant chondrogenesis. This three-dimensional culture model is probably helpful for developing cartilage regeneration in vitro and is further applied in tissue engineering for OA treatment in vivo.

Serum Insulin-like Growth Factor-1 Is a Biomarker of Testosterone Production and Intact Acrosome in Asian Elephants (Elephas maximus).

Simple SummaryIn Thailand, the low fertility rate of Asian elephants has been identified. Factors contributing to poor semen quality in the elephants are not fully understood. Insulin-like growth factor-1 (IGF-1) is related to male infertility. It plays an essential role in testicular development by stimulating cell proliferation, differentiation, and steroidogenesis. In addition, there is increasing evidence that IGF-1 plays a critical role in spermatogenesis. This may be conducive to finding the causes of poor sperm quality in Asian elephants (Elephas maximus). In the present study, we investigated the relationships among serum IGF-1, serum testosterone level, and semen parameters in seven elephant bulls. The findings suggest that serum IGF-1 concentration is likely to predict sperm quality like acrosome integrity. The further mechanism by which IGF-1 affects sperm quality requires further investigation.The objective of this study was to find relationships among serum IGF-1, serum testosterone, seminal plasma IGF-1 concentrations and semen parameters in Asian elephants (Elephas maximus). A total of 17 ejaculates (one to three ejaculates/bull) were collected from seven captive elephant bulls by performing rectal massage. Before each ejaculation, blood samples were obtained for serum IGF-1 and testosterone assays. Subsequently, the semen characteristics of each ejaculate were evaluated. Mean serum IGF-1 concentration of elephant bulls was estimated as 326.3 ± 114.6 ng/mL (median, 286.2 ng/mL; range, 167.4–542.7 ng/mL). An increase in serum IGF-1 concentration was found to correlate with the percentage of spermatozoa with intact acrosomes. In addition, IGF-1 concentration was positively correlated with testosterone level. However, seminal IGF-1 concentrations could not be detected. In conclusion, our findings suggest that serum IGF-1 concentration is likely a biomarker of normal testicular functions, particularly spermatogenesis in elephants. Moreover, this commercial IGF-1 ELISA is eligible for analyzing serum IGF-1 concentration in Asian elephants.

Domestication and domination: Human terminology as a tool for controlling otherthanhuman animal bodies

The language of domestication enables humans to wield power over otherthanhuman animal lives. In some cases, being labelled “domesticated” ensures a life free of worry regarding food, water, and shelter. In others, “domestication” embodies a loss of agency, wildness, and potentially life. Companion animals such as cats find themselves at the center of debates regarding their freedom, reproductive agency, and even their status as domesticates. Others, such as captive elephants, are trapped in liminal spaces by virtue of their labels — “endangered,” “domesticated,” “tamed,” or simply “livestock.” As humans venture further into the world of biotech, these labels become increasingly opaque. With the introduction of hybrid xenobots, transgenic organisms grown of various stem cells, and machine-implanted, sentient species built to serve various functions, we are facing the potential that the word domestication will be again transformed allowing humans to further control the future of otherthanhuman bodies. tient beings they did act in ways the trainers could not predict or control. In so doing, in all cases but refusal to attack they contributed to the excitement of events, and in the case of the elephants of the 55BCE games, even caused the normally hostile spectators to empathize with their plight. When Roman spectators or writers attributed human-like traits to animals who did extraordinary things they tacitly acknowledged animal agency, but this was not transformed into any general acceptance that animals might have any moral sense or cognitive abilities comparable in any way to humans.

Modified vaccinia Ankara expressing EEHV1A glycoprotein B elicits humoral and cell-mediated immune responses in mice.

Elephant endotheliotropic herpesvirus (EEHV) can cause lethal hemorrhagic disease (EEHV-HD) in Asian elephants and is the largest cause of death in captive juvenile Asian elephants in North America and Europe. EEHV-HD also has been documented in captive and wild elephants in their natural range countries. A safe and effective vaccine to prevent lethal EEHV infection would significantly improve conservation efforts for this endangered species. Recent studies from our laboratory suggest that EEHV morbidity and mortality are often associated with primary infection. Therefore, we aim to generate a vaccine, particularly for EEHV1 naïve animals, with the goal of preventing lethal EEHV-HD. To address this goal, we generated a Modified Vaccinia Ankara (MVA) recombinant virus expressing a truncated form of glycoprotein B (gBΔfur731) from EEHV1A, the strain associated with the majority of lethal EEHV cases. Vaccination of CD-1 mice with this recombinant virus induced robust antibody and polyfunctional T cell responses significantly above mice inoculated with wild-type MVA. Although the vaccine-induced T cell response was mainly observed in CD8+ T cell populations, the CD4+ T cell response was also polyfunctional. No adverse responses to vaccination were observed. Overall, our data demonstrates that MVA-gBΔfur731 stimulates robust humoral and cell-mediated responses, supporting its potential translation for use in elephants.

Demographic and health status of captive elephants around Chitwan National Park, Nepal

Abstract. Gautum S, Koju NP. 2022. Demographic and health status of captive elephants around Chitwan National Park, Nepal. Biodiversitas 23: 1621-1627. Elephants have been captive from ancient times. As a keystone species, it requires proper care and management to sustain its viable population in the wild as well as a captive. However, there is a lack of study on captive elephants in Nepal. This study aimed to explore the status of captive elephants in Sauraha, Chitwan National Park, the top tourist destination of Nepal. Field survey, Key-Informant Interview (KII), and questionnaire survey were carried out for the primary source of data collection. During which, 78 mahouts were interviewed. The study revealed 97 (16 males and 81 females) captive elephants in Sauraha during the study period. Among them, 17 were born by captive mothers. The distance traveled by an elephant has recorded 16 km for minimum and 84 km in maximum per day and carries the average weight of 450 kg. Captive elephants belonging to the private company (N=60) were used only in tourism, while captive elephants from National Trust for Nature Conservation (NTNC) and Governments were used in patrolling and transportation. The most common disease in captive elephants is tuberculosis (27%). Similarly, parasitic infections, diseases like foot problems, and colic were also recorded. An effective policy and plan are urgently required to conserve this endangered umbrella species in captivity.

NOVEL DIAGNOSTIC AND THERAPEUTIC APPROACHES TO ELEPHANT ENDOTHELIOTROPIC HERPESVIRUS 1A HEMORRHAGIC DISEASE IN A CAPTIVE JUVENILE ASIAN ELEPHANT (ELEPHAS MAXIMUS).

Novel diagnostic and therapeutic methods were utilized in the successful management of severe elephant endotheliotropic herpesvirus hemorrhagic disease (EEHV-HD) in a 1.9-yr-old captive Asian elephant (Elephas maximus). High levels of EEHV1A viremia were detected for 12 d. In addition to established EEHV treatments, therapies included famciclovir-fortified elephant whole blood and plasma, mesenchymal stem cells harvested from elephant umbilical tissue, and aminocaproic acid. Testing conducted to examine the effects of EEHV infection on hemostasis suggested marked intravascular coagulation with decreased plasminogen activity and increased D-dimer concentrations. Thromboelastography was used to assess the efficacy of aminocaproic acid and demonstrated hypofibrinolysis on samples taken after drug administration, as compared with samples from healthy adult Asian elephants. A serological assay for a novel EEHV1A-specific antibody marker (E52) was developed due to lack of seroconversion to a previously established EEHV1A-specific antibody marker (ORFQ) and showed a sustained increase after EEHV-HD illness.

Study of fecal glucocorticoid metabolites in captive Asian elephants in Kanchanaburi Province, Thailand.

Background and Aim:Over the past two decades, the number of elephant camps in Thailand has increased considerably, and captive elephants have become more popular within the tourism industry. Tourist activities involving elephant exhibitions and trekking potentially affect animal health and welfare. This study aimed to investigate the relationships between a novel stress biomarker, fecal glucocorticoid metabolites (fGCM), and various factors (sex, age, weather season, tourist season, and elephant usage patterns), monitoring the fGCM concentration during and after trekking activities ceased.Materials and Methods:Fecal samples of 20 captive Asian elephants from two camps in Kanchanaburi Province were collected monthly for 1 year. The fGCM concentrations were measured using enzyme immunoassay and evaluated relative to individual demography, season, and tourist trekking activity. The mean differences of fGCMs concentrations were compared by analysis of variance and t-test statistics according to data types with p<0.5.Results:Significant differences in mean fGCM concentrations were found between age categories (p=0.001), trekking and non-trekking animals (p=0.039), and during and after trekking (p=0.023). The mean fGCM concentration of elephants aged during 0-44 years (136.7 ng/g) was significantly higher than for animals over 44 years old (107.7 ng/g), and the elephant trekking group (144.9 ng/g) was significantly higher than the other group (124.7 ng/g). Within the trekking group, the mean fGCM concentrations gradually declined to 129.13 ng/g within 8 months of trekking cessation.Conclusion:Elephant’s ages and activities co-influenced the variance of fGCM concentrations. In addition, permanent tourist activity, especially trekking, can increase elephant stress. This study’s findings can be applied to the health status monitoring of captive elephants and result in improved animal welfare.

Improving care of captive elephants

Improving care of captive elephants

Elephant Endotheliotropic Herpesvirus 1, 4 and 5 in China: Occurrence in Multiple Sample Types and Implications for Wild and Captive Population Surveillance.

Elephant endotheliotropic herpesviruses (EEHVs) are important causes of death in both captive and wild Asian elephants (Elephas maximus). Nothing is known about the prevalence of EEHVs in wild or domestic elephants in China. To determine if EEHVs are present in elephants in China, 126 wild elephants from three populations and 202 captive individuals from zoos (n = 155) and the Wild Elephant Valley (n = 47) were screened using semi-nested polymerase chain reaction assays with EEHV-redundant and EEHV1/4/5-specific primers. EEHV1B and EEHV4 were detected in samples from both wild (EEHV1B:8/126; EEHV4:2/126) and captive (EEHV1B:5/155; EEHV4:9/155) elephants, while EEHV1A (six cases) and EEHV5 (one case) were only present in the captive elephants from the Wild Elephant Valley. EEHV1 was detected in blood and trunk and oral swabs; EEHV4 was detected in trunk and oral swabs as well as feces; EEHV5 was found in trunk and oral swabs. No significant age or sex association with EEHV1A, EEHV1B, or EEHV5 positivity was observed. An age association with EEHV4 positivity was found, with all unweaned elephants being EEHV4 positive, but an association with the sex of the elephant was not observed. These findings represent the first documentation of EEHV presence in captive and wild elephants in China. These findings also document EEHV1B and EEHV4 shedding in feces and demonstrate the utility of fecal screening as a tool for investigating EEHV4 infection in wild populations of elephants. It is recommended that EEHV testing be included in surveillance programs for captive and wild elephants in China.

Some population characteristics and viability of captive Asian elephant (Elephas maximus) in Thailand

Abstract. Pla-ard M, Sukmasuang R, Uthairasmee S. 2022. Some population characteristics and viability of captive Asian elephant (Elephas maximus) in Thailand. Biodiversitas 23: 1072-1081. Sustaining long-term viable populations of captive Asian elephants poses a challenge in managing the existing populations. Therefore, studies of the characterization and long-term persistence of the population are an important aspect of the action. The results of long-term population analysis of captive Asian elephants (Elephas maximus Linnaeus, 1758) using Population Viability Analysis (PVA) from the demography information showed that the birth and reproductive rate of the captive elephants in Thailand are declining significantly while the mortality rate trends are stable. Analysis results of the population's ability to persist in the long term from the initial population of 4,252 elephants, it was found that extinction of the population if the percentage adult female breeding is 80%, which is the best-case scenario, if the mortality rate increases by 6% from the present, the population will start going into extinction. If the percentage adult female breeding is set to 2.3%, which is the lowest breeding condition in captive Asian elephants, the population will become extinct in every scenario. Therefore, the most important method in maintaining the captive Asian elephant population is to increase the birth rate improve the well-being, health, nutrition, environment, and welfare of elephants in captivity are important factors that would reduce deaths and are very important for the long-term survival of the population in Thailand.

Characteristics of social relationships in a group of captive Asian elephants (Elephas maximus) in the elephant village in Thailand

Wild Asian elephants (Elephas maximus) form complex fission–fusion societies centered on matrilineal groups. In captivity, unrelated females remain in the same group and create social relationships. To better understand well-being in captivity, it is important to investigate the social relationships between females. However, to date, little information is available on this topic. The goal of this study was to clarify the social relationships between captive female Asian elephants using social network analysis. Our subjects were 13 captive Asian elephants at the Elephant Study Center in Surin Province, Thailand. We investigated variations in the frequencies of affiliative behaviors between dyads. Individuals that stayed in the group longer tended to play a more central role in terms of group member connections. We found that two individuals played an important role in strengthening connections, and that their removal influenced group cohesion. Our results revealed that individuals that stayed in the group long-term and that had existing relationships with others in the group tended to build better social connections, regardless of their age. In addition, the existence of some young individuals that show frequent affiliative behaviors may be important for bond strength and therefore, overall group cohesion.

PRIMER OPTIMIZATION AS GENETIC MARKER PRIMER BASED ON CYTOCHROME B GENE ON SUMATRAN ELEPHANT (Elephas maximus sumatranus) NON-INVASIVE SAMPLES

Sumatran elephant is declared as critically endangered by IUCN since 2011. In supporting conservation efforts on sumatran elephant in its natural habitat, molecular data collection of their population needs to be done. Genetic source material is mostly obtained in its natural habitat is its dung/feces. Study on cytochrome B gene as genetic marker from sumatran elephant fecal samples can be done to get additional genetic data as a form of conservation effort. Primer optimization as genetic marker based on cytochrome B gene has been carried out as an early study on sumatran elephant genetics. Primer optimization program based on cytochrome B genetic marker from sumatran elephant fecal samples was under Higher Education Applied Research funded by The Ministry of Research, Technology, and Higher Education. DNA was isolated from fecal samples of captive sumatran elephants in Elephant Training Center, Way Kambas National Park. Primer optimization was done via amplification by increasing certain temperature. Specificity test was done to ensure that the primer only recognized sumatran elephant DNA. The best result was obtained with the annealing temperature of 52oC

Ionized Calcium and Serum Electrolytes Profile in Captive Asian Elephants (Elephas maximus) of Tamil Nadu, India

Background: Serum electrolyte monitoring is essential in the health assessment of captive elephants. The major elements of calcium, sodium, potassium, chloride and bicarbonate are playing a major role in regulation of nerve and muscle functions and in maintaining acid base and water balance. Excess levels or loss of particular electrolytes may occur as secondary changes caused by certain diseases or changes in physiological regulations. The aim of this study was to evolve the baseline reference values for serum electrolyte levels in captive Asian elephants raised in Tamil Nadu state of India. Methods: As part of the periodical health assessment blood samples were collected from auricular vein for 42 apparently healthy captive Asian elephants in Tamil Nadu, India. Serum electrolyte levels such as sodium (Na+), potassium (K+), chloride (Cl-), ionized calcium (iCa), non-ionized calcium and total calcium (tCa) were determined by using an automated electrolyte analyzer. Result: Most of the ranges of electrolyte values observed in this study were similar to that of previous reports. As not much studies on ionized calcium are available on captive Asian elephants the value of ionized calcium found this study 1.16±0.13 mmol/L could serve as reference. There was no much variation observed in various age groups. This electrolyte profile values will serve as baseline values to evaluate the health and clinical conditions of captive elephant populations.

Elephants in Nepal: Correlating disease, tourism, and welfare

ABSTRACT Asian elephants and humans have long shared their lives, but recent changes in human perspectives on animal use have created ripples through the small country of Nepal. Captive elephants are caught in the crossfire between local communities, elephant owners, mahouts, and NGOs in debates over their treatment, health, welfare and use in tourism. In addition, zoonotic disease, natural disasters and political strife affect the lives of captive elephants and mahouts. For example, during the COVID-19 pandemic, elephants, caregivers and owners found themselves facing income loss, decreased welfare from housing and husbandry issues, and food shortages. Many owners sold elephants, fired mahouts, and “quit” the tourism industry. Others sought help from outside organizations, community members, and governmental agencies to retain ownership of what they viewed as valuable commodities. NGOs and grassroots organizations assisted in the hopes of keeping elephants in Nepal, thus preventing them from long, treacherous walks across the border and into situations where they might face further welfare decreases. This article combines elephant stable visits and interviews with mahouts, owners, NGO, and government staff between January 2019 and December 2021. It highlights the ongoing health and welfare challenges faced by elephants and mahouts in Nepal.

Determining the Dietary Preferences of Wild Asian Elephants (Elephas maximus) in Taman Negara National Park, Malaysia Based on Sex and Age using trnL DNA Metabarcoding Analysis.

The world's largest terrestrial mammal, Asian elephants, are known to have enormous feeding needs. Several factors such as season, sex, age, and daily activities influence the amount of food required by an individual. Generally, captive elephants have a limited choice of food on a daily basis compared with that of elephants in the wild. Elephants in captivity are fed according to a prepared feeding schedule, whereas wild elephants are free to choose the type of plants that they consume in their natural habitat. In the past, ecological observations have been widely used to determine the diet of wild elephants. However, the molecular approach has never been carried out. In the present study, we aimed to; 1) identify the plant diet of wild Asian elephants in Taman Negara National Park (TNNP) according to their sex and age using high-throughput DNA metabarcoding; and 2) determine the dietary formulation of captive elephants based on the generated plant metabarcoding database. DNA was extracted from 24 individual fecal samples collected using noninvasive sampling techniques from TNNP and the National Elephant Conservation Centre (NECC) Kuala Gandah. Seven pooled samples from male adult, female adult, male subadult, female subadult, male juvenile, female juvenile, and captive elephants were amplified and sequenced targeting the trnL region (50-150 base pairs). The CLC Genomic Workbench and PAST 4.02 software were used for data analysis. In total, 24 orders, 41 families, 233 genera, and 306 species of plants were successfully detected in the diet of the Asian elephants. The most abundant plant genera consumed were Sporobolus (21.88%), Musa (21.48%), and Ficus (10.80%). Plant variation was lower in samples from male elephants than in those from female elephants. The plant species identified were correlated with the nutrient benefits required by elephants. Adults and subadults consumed more plant species than were consumed by juvenile elephants. However, there was no significant difference between ages and sexes. The findings of this study can be used as guidance by the Department of Wildlife and National Parks for the management of captive elephants, especially in NECC Kuala Gandah.

ELEPHANT ENDOTHELIOTROPIC HERPESVIRUS HEMORRHAGIC DISEASE OUTBREAK IN AN INDIAN ZOO.

Elephant endotheliotropic herpesvirus hemorrhagic disease (EEHV HD) is an acute viral infection of growing Asian elephants (Elephas maximus). Four apparently healthy subadult Asian elephants aged between 6 and 10 yr at Nandankanan Zoological Park (NKZP), India, died of EEHV HD during August-September 2019. All four elephants were rescued from different reserved forests of Odisha state at less than 1 yr of age and hand reared in the NKZP. Elephants exhibited the clinical signs of lethargy, head swelling, fever, loss of appetite, abdominal distension, scant urination and defecation, signs of colic, lameness, trunk discharge, cyanosis/ulceration of tongue, erratic behavior, and recumbence before death. Period of illness varied between 28 and 42 h. Thrombocytopenia was the common significant hematological observation. No significant biochemical alterations were recorded except for higher creatinine concentrations. Analysis of blood samples in RT-PCR assay using two different sets of primers and probes that targeted terminase gene and major DNA-binding protein gene followed by cPCR and sequencing was positive for EEHV-1A in all four animals. Postmortem examination of all four carcasses showed hemorrhages in internal organs, including the hard palate, heart, lungs, stomach, mesenteric lymph nodes, mesentery, colon serosa, spleen, liver, kidney, and meninges. Histopathology showed congestion and/or hemorrhages in heart, lung, brain, kidney, and liver. There was presence of intranuclear inclusion bodies in the sinusoidal epithelial cells. The outbreak of EEHV HD that resulted in the acute death of four juvenile captive Asian elephants within <30 d, the first of its kind documented in India, is increasing the fear of similar outbreaks in the future.

Effects of Positive Reinforcement Training and Novel Object Exposure on Salivary Cortisol Levels under Consideration of Individual Variation in Captive African Elephants (Loxodonta africana).

Simple SummaryRegular training for medical or enrichment purposes and the provision of environmental enrichment, such as varied feeding schedules and novel objects, are part of the management of African elephants in zoos. The present study aimed to find out whether training and enrichment in the form of a novel object induced physiological changes in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) before and after training and the exposure to a novel object for the analysis of cortisol and as a measure of stress and arousal. We found high salivary cortisol levels before and low levels after training. A novel object, in contrast, moderately increased the salivary cortisol levels. Moreover, males and young elephants showed lower salivary cortisol levels than females and old elephants, respectively. The zoo, handling method (free vs. protected contact to keepers), reproductive and social status, however, did not influence the salivary cortisol levels of the animals studied. We conclude that the relatively high cortisol values before training could be due to anticipation of the training event. A novel object, in contrast, may have evoked arousal, which led to the observed cortisol increase. In addition, understanding why animals differ in stress responses will help to manage stress in zoo elephants with the goal of ensuring their welfare.Dealing with potential stress in species that have high husbandry requirements, such as elephants, is a challenge for zoos. The objective of the present study was to determine whether positive reinforcement training (PRT) and exposure to a novel object (NOV) for enrichment induced a salivary cortisol response indicative of activation of the hypothalamic–pituitary–adrenal (HPA) axis and which factors determine individual variation in this regard in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) for the analysis of cortisol (SACort) before and up to 60 min (in 10–15 min intervals) after the onset of PRT (three repeats) or NOV (nine repeats), which lasted 10 min. There was considerable individual variation in SACort in response to PRT or NOV. Using mixed models, we were able to control these and to reveal that PRT was associated with high SACort before and relatively low SACort after PRT, while NOV induced a moderate SACort increase. The individual differences in SACort were related to age and sex (NOV), while the effects of zoo, handling method (free vs. protected contact) and reproductive and social status were variable. We conclude that positive affective states, such as anticipation or arousal, should be taken into account when interpreting the differences in the SACort responses between PRT and NOV. In addition, understanding the individuality of stress will support management decisions aimed at promoting captive elephant welfare.

Clinical health issues, reproductive hormones, and metabolic hormones associated with gut microbiome structure in African and Asian elephants

BackgroundThe gut microbiome is important to immune health, metabolism, and hormone regulation. Understanding host–microbiome relationships in captive animals may lead to mediating long term health issues common in captive animals. For instance, zoo managed African elephants (Loxodonta africana) and Asian elephants (Elephas maximus) experience low reproductive rates, high body condition, and gastrointestinal (GI) issues. We leveraged an extensive collection of fecal samples and health records from the Elephant Welfare Study conducted across North American zoos in 2012 to examine the link between gut microbiota and clinical health issues, reproductive hormones, and metabolic hormones in captive elephants. We quantified gut microbiomes of 69 African and 48 Asian elephants from across 50 zoos using Illumina sequencing of the 16S rRNA bacterial gene.ResultsElephant species differed in microbiome structure, with African elephants having lower bacterial richness and dissimilar bacterial composition from Asian elephants. In both species, bacterial composition was strongly influenced by zoo facility. Bacterial richness was lower in African elephants with recent GI issues, and richness was positively correlated with metabolic hormone total triiodothyronine (total T3) in Asian elephants. We found species-specific associations between gut microbiome composition and hormones: Asian elephant gut microbiome composition was linked to total T3 and free thyroxine (free T4), while fecal glucocorticoid metabolites (FGM) were linked to African elephant gut microbiome composition. We identified many relationships between bacterial relative abundances and hormone concentrations, including Prevotella spp., Treponema spp., and Akkermansia spp.ConclusionsWe present a comprehensive assessment of relationships between the gut microbiome, host species, environment, clinical health issues, and the endocrine system in captive elephants. Our results highlight the combined significance of host species-specific regulation and environmental effects on the gut microbiome between two elephant species and across 50 zoo facilities. We provide evidence of clinical health issues, reproductive hormones, and metabolic hormones associated with the gut microbiome structure of captive elephants. Our findings establish the groundwork for future studies to investigate bacterial function or develop tools (e.g., prebiotics, probiotics, dietary manipulations) suitable for conservation and zoo management.