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1.
Ecol Evol ; 13(10): e10560, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37780084

ABSTRACT

Elephants were once widely distributed across the Indonesian island of Sumatra but now exist in small, isolated populations. Using the best data available on elephant occurrence, we aimed to (a) predict potential habitat suitability for elephants (Elephas maximus sumatranus) across the island of Sumatra and (b) model landscape connectivity among the extant elephant populations. We used direct sightings and indirect observations of elephant signs, as well as six remotely sensed proxies of surface ruggedness, vegetation productivity and structure, and human land use and disturbance, to model habitat suitability in a Google Earth Engine (GEE) environment. We validated the habitat suitability prediction using 10-fold spatial block cross validation and by calculating the area under the precision-recall curve (AUC-PR), sensitivity, and specificity for each model iteration. We also used a geolocation dataset collected from global positioning system (GPS) collars fitted on elephants as an independent validation dataset. Models showed good predictive performance with a mean AUC-PR of 0.73, sensitivity of 0.76, and specificity of 0.68. Greater than 83% of the independent GPS collar geolocations were located in predicted suitable habitat. We found human modification, surface ruggedness, and normalized difference vegetation index to be the most important variables for predicting suitable elephant habitat. Thirty-two percent, or 135,646 km2, of Sumatra's land area was predicted to be suitable habitat, with 43 patches of suitable habitat located across Sumatra. Areas with high connectivity were concentrated in the Riau and North Sumatra provinces. Though our analysis highlights the need to improve the quality of data collected on Sumatran elephants, more suitable habitat remains on Sumatra than is used by known populations. Targeted habitat conservation, especially of the suitable habitat in and around the Lamno, Balai Raja, Tesso Tenggara, Tesso Utara, Bukit Tigapuluh, Seblat, Padang Sugihan, and Bukit Barisan Selatan ranges, may improve the long-term viability of this critically endangered species.

2.
Front Vet Sci ; 10: 1204880, 2023.
Article in English | MEDLINE | ID: mdl-37745210

ABSTRACT

Serum protein electrophoresis has been demonstrated to have utility in diagnostic workup, wellness exams, and prognosis. Agarose gel electrophoresis (AGE) has previously been described for use with serum from Asian elephants (Elephas maximus). As the newer method of capillary zone electrophoresis (CZE) is becoming more commonplace in veterinary diagnostic laboratories, serum samples from Asian elephants were examined using this method. CZE allowed for a reproducible definition of two beta fractions and, overall, showed a low coefficient of variation for fraction quantitation. Preliminary reference intervals were generated using samples primarily from an older population of 22 female elephants. Albumin levels determined by CZE were also compared with those determined by the bromocresol green method on a chemistry analyzer. It was found that the latter method overestimated the level of albumin with a mean positive bias of 11.6% or 0.38 g/dL, thus method-specific reference intervals should be used. Significant negative correlations were observed between A/G ratio determined by CZE and serum amyloid A levels (r = -0.47, p < 0.0001) and haptoglobin (r = -0.52, p < 0.0001); both APP were significantly correlated with the alpha 2 globulin fraction (p < 0.0001). CZE reflects an overall picture of changes in acute phase proteins and immunoglobulins and accurate quantitation of albumin and thus should be considered as an adjunct tool to the use of other measures of the acute phase response in patient monitoring.

3.
Animals (Basel) ; 13(16)2023 Aug 14.
Article in English | MEDLINE | ID: mdl-37627408

ABSTRACT

Humans overlap with Asian elephants, resulting in frequent costly human-elephant conflicts, which disturb and even threaten local residents. In this study, we treat provincial and national nature reserves where Asian elephants still exist and other alternative habitats suitable for Asian elephants in southern Yunnan, China, as ecological patches. By using this approach, we can treat the terrain and surface state factors that hinder the migration of Asian elephants as a form of ecological resistance surface. We can then use a circuit theory model and remote sensing data to construct an ecological network, which allows us to identify ecological corridors and ecological pinch points. Herein, the possible migration routes of wild Asian elephants were identified. The main results are as follows: (1) In the study area, dense forests with steep slopes and high altitudes, cultivated land, and building land have greater migration resistance, while the gently undulating shrubs, bamboo forests, and grasslands far away from the city have less migration resistance. (2) There are three ecological corridor groups in the study area, mainly composed of shrub and grassland. The ecological corridors identified in this paper are the most likely migration routes of wild Asian elephants in China, and areas with higher simulated current densities reflect a higher probability of Asian elephants passing through. (3) According to the analysis, the ecological pinch points in the study area are 602 km2 in total, and woodland and grassland account for 89.2% of the total ecological pinch area. The areas where the pinch points are located have a high probability of Asian elephants passing through and a narrow space. Our findings can provide suggestions and solutions for the current conservation of wild Asian elephant species, alleviate human-elephant conflicts, promote the harmonious coexistence between humans and nature, and provide reference for biological protection and biological reserve planning.

4.
Animals (Basel) ; 13(16)2023 Aug 18.
Article in English | MEDLINE | ID: mdl-37627448

ABSTRACT

Aversive geofencing devices (AGDs) or animal-borne satellite-linked shock collars might become a useful tool to mitigate human-elephant conflict (HEC). AGDs have the potential to condition problem elephants to avoid human-dominated landscapes by associating mild electric shocks with preceding audio warnings given as they approach virtual boundaries. We assessed the opinions of different stakeholders (experts, farmers, and others who have and have not experienced HEC; n = 611) on the potential use of AGDs on Asian elephants. Most respondents expressed positive opinions on the potential effectiveness of AGDs in managing elephant movement (62.2%). About 62.8% respondents also provided positive responses for the acceptability of AGDs if pilot studies with captive elephants have been successful in managing their movements. Some respondents perceived AGDs to be unacceptable because they are unethical or harmful and would be unsuccessful given wild elephants may respond differently to AGDs than captive elephants. Respondents identified acceptability, support and awareness of stakeholders, safety and wellbeing of elephants, logistical difficulties, durability and reliable functionality of AGDs, and uncertainties in elephants' responses to AGDs as potential challenges for implementing AGDs. These issues need attention when developing AGDs to increase support from stakeholders and to effectively reduce HEC incidents in the future.

5.
Microbiome ; 11(1): 148, 2023 07 06.
Article in English | MEDLINE | ID: mdl-37408039

ABSTRACT

BACKGROUND: Gut microbiota have a complex role on the survivability, digestive physiology, production, and growth performance in animals. Recent studies have emphasized the effects of prebiotics therapy on the gut disease, but the relationship between elephant gut-related diseases and prebiotics remains elusive. Here, a case study was undertaken to evaluate the mechanism of inulin treatment in colic in Asian elephant (Elephas maximus Linnaeus). METHODS: Fecal samples were collected from a sick elephant and four healthy elephants. Analysis of microbial profile was carried out by 16S rRNA sequencing, and the short chain fatty acids were tested by gas chromatography. The physiological function of "inulin-microbiota" of elephant was verified in mice by fecal microbial transplantation (FMT). The expression of related proteins was determined by Western blotting and qPCR. RESULTS: (1) Eating inulin can cure gut colic of the sick elephant and changed gut microbiota. (2) It was found that "inulin microbiota" from the post-treatment elephants can promote the proliferation of intestinal cells, increase the utilization of short chain fatty acids (SCFAs), maintain intestinal barrier, and reduce the inflammation in mice. (3) The mechanism was inulin-gut microbiota-SCFAs-immune barrier. CONCLUSIONS: Inulin contributed to rehabilitate the gut microbiota and gut immune barrier of the elephant with colic. This provides reasonable verification for using prebiotics to treat the colic in captive elephants. Prebiotics will foresure play an increasingly important role in disease prevention and treatment of captive animals in the future. Video Abstract.


Subject(s)
Colic , Elephants , Gastrointestinal Microbiome , Animals , Mice , Inulin , Elephants/genetics , Prebiotics/analysis , Gastrointestinal Microbiome/genetics , RNA, Ribosomal, 16S/genetics , Fatty Acids, Volatile/analysis
6.
Front Vet Sci ; 10: 1133823, 2023.
Article in English | MEDLINE | ID: mdl-37303725

ABSTRACT

Introduction: Tuberculosis is an infectious disease caused by a group of acid-fast bacilli known as Mycobacterium tuberculosis complex (MTC), which has a major impact on humans. Transmission of MTC across the human-animal interface has been demonstrated by several studies. However, the reverse zoonotic transmission from humans to animals (zooanthroponosis) has often been neglected. Methods: In this study, we used Nanopore MinION and Illumina MiSeq approaches to sequence the whole genome of M. tuberculosis strains isolated from two deceased Asian elephants (Elephas maximus) and one human in Chitwan, Nepal. The evolutionary relationships and drug resistance capacity of these strains were assessed using the whole genome data generated by the stand-alone tool Tb-Profiler. Phylogenomic trees were also constructed using a non-synonymous SNP alignment of 2,596 bp, including 94 whole genome sequences representative of the previously described M. tuberculosis lineages from elephants worldwide (lineages 1 and 4) and from humans in Nepal (lineages 1, 2 and 3). Results and Discussion: The new genomes achieved an average coverage of 99.6%, with an average depth of 55.67x. These M. tuberculosis strains belong to lineage 1 (elephant DG), lineage 2 (elephant PK) and lineage 4 (human), and none of them were found to have drug-resistant variants. The elephant-derived isolates were evolutionarily closely related to human-derived isolates previously described in Nepal, both in lineages 1 and 2, providing additional support for zooanthroponosis or bidirectional transmission between humans and elephants. The human-derived isolate clustered together with other published human isolates from Argentina, Russia and the United Kingdom in the lineage 4 clade. This complex multi-pathogen, multi-host system is challenging and highlights the need for a One Health approach to tuberculosis prevention and control at human-animal interface, particularly in regions where human tuberculosis is highly endemic.

7.
Antibiotics (Basel) ; 12(5)2023 May 06.
Article in English | MEDLINE | ID: mdl-37237762

ABSTRACT

The Asian elephant (Elephas maximus) is a flagship species of tropical rainforests, and it has generated much concern. In this case, the gut bacterial communities of captive and wild Asian elephants are particularly noteworthy. We aim to compare the differences in bacterial diversity and antibiotic resistance gene (ARG) subtypes in fecal samples of Asian elephants from different habitats, which may affect host health. Analyses reveal that differences in the dominant species of gut bacteria between captive and wild Asian elephants may result in significant differences in ARGs. Network analysis of bacterial communities in captive Asian elephants has identified potentially pathogenic species. Many negative correlations in network analysis suggest that different food sources may lead to differences in bacterial communities and ARGs. Results also indicate that the ARG levels in local captive breeding of Asian elephants are close to those of the wild type. However, we found that local captive elephants carry fewer ARG types than their wild counterparts. This study reveals the profile and relationship between bacterial communities and ARGs in different sources of Asian elephant feces, providing primary data for captive breeding and rescuing wild Asian elephants.

8.
Eur J Protistol ; 89: 125986, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37121145

ABSTRACT

The genera Raabena and Pararaabena (Ciliophora, Entodiniomorphida, Blepharocorythidae) were monospecific, and their type species are Raabena bella Wolska, 1967 and Pararaabena dentata Wolska, 1968. They have been found in Asian elephants and closely resemble each other: ovoid and laterally compressed body; non-retractable adoral ciliary zone; funnel-shaped vestibulum; three non-retractable somatic ciliary arches. Furthermore, the positional relationship between the vestibular ciliary zone and the anterior dorsal ciliary zone identifies Raabena and Pararaabena: these two ciliary zones are connected in Raabena while they are separated in Pararaabena. While investigating entodiniomorphid ciliates of Asian elephants, the author often encountered ciliates similar to Raabena bella but with a sinuous body or with a small body and ciliates similar to Pararaabena dentata but with a slender body or with no or two caudal lobes. In this study, their general morphology and infraciliature were compared to R. bella and P. dentata to know whether they are new species or morphological variations in a species. As a result, the present study redescribed R. bella and P. dentata, and described R. sinuosa n. sp., R. bellafilia n. sp., P. gracilis n. sp., and morphotypes of P. dentata.


Subject(s)
Ciliophora , Elephants , Animals
9.
J Vet Med Sci ; 85(5): 578-583, 2023 May 03.
Article in English | MEDLINE | ID: mdl-36927856

ABSTRACT

Serum levels of creatine kinase (CK) and lactate dehydrogenase (LDH) isoenzymes were evaluated in nine zoo-managed Asian elephants (Elephas maximus) using a commercial agarose gel electrophoresis (AGE) kit. CK was separated into two major fractions, CK-BB and CK-MM, along with a small fraction of macroenzyme-CK type 2 (mCK2); CK-MM was the largest fraction. LDH was separated into five fractions (LDH1-5); LDH3 was the largest fraction. Age was negatively and positively correlated with the percentages of CK-BB and CK-MM, respectively, and negatively correlated with CK-BB and mCK2 activities. These results indicate that an AGE kit can be used to evaluate CK and LDH isoenzymes. Routine isoenzyme testing may enable early detection of disease and physiological changes.


Subject(s)
Elephants , Animals , Isoenzymes , Creatine Kinase , L-Lactate Dehydrogenase , Electrophoresis, Agar Gel/veterinary
10.
J Vet Med Sci ; 85(4): 459-462, 2023 Mar 30.
Article in English | MEDLINE | ID: mdl-36792210

ABSTRACT

Elephant endotheliotropic herpesvirus (EEHV) causes a fatal hemorrhagic disease and is a significant cause of mortality in juvenile Asian elephants. A loop-mediated isothermal amplification (LAMP) method was developed to rapidly diagnose EEHV viremia. However, extracting DNA from whole blood samples to perform LAMP hampers diagnosis in a field setting. Here, we established the Direct-LAMP method, using heparinized plasma without extracting the DNA to speed up and simplify the test. EEHV-positive specimens were tested using the Direct-LAMP. The detection limit was calculated to be 101.3 copies/µL using the mimetic samples, which was almost identical to the value determined in LAMP in which DNA was extracted. Hence, the Direct-LAMP provided a more rapid diagnosis to save, which could prevent elephant deaths.


Subject(s)
Elephants , Herpesviridae Infections , Herpesviridae , Animals , Herpesviridae Infections/diagnosis , Herpesviridae Infections/veterinary , Herpesviridae/genetics , DNA
11.
J Vet Med Sci ; 85(2): 232-235, 2023 Feb 10.
Article in English | MEDLINE | ID: mdl-36543184

ABSTRACT

The approved Japanese measurement method of circulating alkaline phosphatase (ALP) has changed from that of the Japan Society of Clinical Chemistry (JSCC) to that of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). We measured the serum levels of total ALP (t-ALP) and those of the isoenzymes ALP2 and ALP3 in 50 Asian elephant (Elephas maximus) specimens using both methods. The activities determined by the IFCC method were roughly one-third lower than those determined by the JSCC method. We present conversion formulae. Our results enable comparisons of historical and current data on serum ALP activities in endangered, zoo-managed Asian elephants.


Subject(s)
Elephants , Isoenzymes , Animals , Alkaline Phosphatase , Chemistry, Clinical , Coloring Agents , Animals, Zoo
12.
Integr Zool ; 18(3): 453-468, 2023 May.
Article in English | MEDLINE | ID: mdl-36052971

ABSTRACT

A herd of 15 Chinese elephants attracted international attention during their 2021 northward trek, motivating the government to propose establishment of an Asian elephant national park. However, planning is hampered by a lack of genetic information on the remaining populations in China. We collected DNA from 497 dung samples from all 5 populations encompassing the entire range of elephants in China and used mitochondrial and microsatellite markers to investigate their genetic and demographic structure. We identified 237 unique genotypes (153 females, 84 males), representing 81% of the known population. However, the effective population size was small (28, range 25-32). Historic demographic contraction appeared to account for low haplotype diversity (Hd = 0.235), but moderate nucleotide and nuclear diversity (π = 0.6%, He = 0.55) was attributable to post-bottleneck recovery involving recent population expansion plus historical gene exchange with elephants in Myanmar, Lao PDR, and Vietnam. The 5 populations fell into 3 clusters, with Nangunhe elephants differing consistently from the other 4 populations (FST = 0.23); elephants from Mengyang, Simao, and Jiangcheng belonged to a single population (henceforth, MSJ), and differed from the Shangyong population (FST = 0.11). Interpopulation genetic variation reflected isolation by distance and female-biased dispersal. Chinese elephants should be managed as 2 distinct units: Nangunhe and another combining Shangyong and MSJ; their long-term viability will require restoring gene flow between Shangyong and MSJ, and between elephants in China and neighboring countries. Our results have the potential to inform conservation planning for an iconic megafaunal species.


Subject(s)
Elephants , China , Population Dynamics , Haplotypes , Genetic Variation , Male , Female
13.
Animals (Basel) ; 12(21)2022 Oct 28.
Article in English | MEDLINE | ID: mdl-36359089

ABSTRACT

Asian elephants are a principal cause of human-wildlife conflict. This results in the death/injury of elephants and humans and large-scale crop and property damage. Most current human-elephant conflict (HEC) mitigation tools lack the flexibility to accommodate the ecological needs of elephants and are ineffective at reducing HEC in the long-term. Here we review common HEC mitigation tools used in Asia and the potential of Aversive Geofencing Devices (AGDs) to manage problem elephants. AGDs can be configured to monitor animal movements in real-time and deliver auditory warnings followed by electric stimuli whenever animals attempt to move across user-specified virtual boundaries. Thus, AGDs are expected to condition elephants to avoid receiving shocks and keep them away from virtually fenced areas, while providing alternative routes that can be modified if required. Studies conducted using AGDs with other species provide an overview of their potential in conditioning wild animals. We recommend that the efficacy and welfare impact of AGDs be evaluated using captive elephants along with public perception of using AGDs on elephants as a means of addressing the inherent deficiencies of common HEC mitigation tools. If elephants could be successfully conditioned to avoid virtual fences, then AGDs could resolve many HEC incidents throughout Asia.

14.
Animals (Basel) ; 12(19)2022 Oct 10.
Article in English | MEDLINE | ID: mdl-36230461

ABSTRACT

Tropical Rainforest Heritage sites of Sumatra are some of the most irreplaceable landscapes in the world for biodiversity conservation. These landscapes harbor many endangered Asiatic mammals all suffering multifaceted threats due to anthropogenic activities. Three charismatic mammals in Sumatra: Elephas maximus sumatranus, Pongo abelii, and Panthera tigris sumatrae are protected and listed as Critically Endangered (CR) within the IUCN Red List. Nevertheless, their current geographic distribution remains unclear, and the impact of environmental factors on these species are mostly unknown. This study predicts the potential range of those species on the island of Sumatra using anthropogenic, biophysical, topographic, and climatic parameters based on the ensemble machine learning algorithms. We also investigated the effects of habitat loss from current land use, ecosystem availability, and importance of Indonesian protected areas. Our predictive model had relatively excellent performance (Sørensen: 0.81-0.94) and can enhance knowledge on the current species distributions. The most critical environmental predictors for the distribution of the three species are conservation status and temperature seasonality. This study revealed that more than half of the species distributions occurred in non-protected areas, with proportional coverage being 83%, 72%, and 54% for E.m. sumatranus, P. abelii, and P.t. sumatrae, respectively. Our study further provides reliable information on places where conservation efforts must be prioritized, both inside and outside of the protected area networks, to safeguard the ongoing survival of these Indonesian large charismatic mammals.

15.
Animals (Basel) ; 12(15)2022 Aug 08.
Article in English | MEDLINE | ID: mdl-35953994

ABSTRACT

Reproductive tumors can impact conception, pregnancy, and birth in mammals. These impacts are well documented in humans, while data in other mammals are limited. An urgent need exists to understand the reproductive impact of these lesions in endangered species, because some endangered species have a documented high prevalence of reproductive tumors. This article documents that the prevalence of both benign and malignant neoplasia differs between African and Asian elephants, with Asian elephants more frequently diagnosed and negatively affected by both. The prevalence of these tumors across mammalian species is compared, and impact plus treatment options in human medicine are reviewed to inform decision making in elephants. Evidence suggests that reproductive tumors can negatively impact elephant conservation. Future studies that document reproductive outcomes, including the success of various treatment approaches in elephants with tumors will benefit conservation efforts.

16.
BMC Vet Res ; 18(1): 262, 2022 Jul 06.
Article in English | MEDLINE | ID: mdl-35794608

ABSTRACT

BACKGROUND: Mycobacterium tuberculosis complex (MTC) that causes the chronic infectious disease- tuberculosis (TB), often presents with a complicated epidemiological pattern where the transmission chain may include humans, domestic animals and wildlife, including elephants. TB has been reported globally in both captive and wild elephants. The One Health approach might be the most effective way of understanding the shared MTC infection dynamics in captive and wild animals like Asian elephants. This systematic review accumulates evidence on occurrence, transmission pathways, and preventive measures of TB in elephants from a One Health perspective. RESULTS: The prevalence of TB reported in elephant populations ranges from 0 to 23.33% and high prevalence's are reported for elephants that are in close proximity to infected humans. The risk of elephant to human infection transmission increased significantly with exposure duration and contact with infected elephants. Some studies described the plausible TB transmission to captive elephants from other animals (wild and domestic), suggesting inter- and intra-species transmission. The results of this systematic review based on 27 relevant published works, suggest three overarching interrelated transmission pathways for M. tuberculosis infections in Asian elephants- i) humans and elephants, ii) other animals (wild or domestic) and elephants and iii) unclear sources of infection. CONCLUSIONS: The progress made with new TB diagnostic tools provides multiple methods to choose from. However, lack of harmonization of TB testing in elephants and their human contacts remains a challenge to prevent TB in those animals. Routine TB screening among elephants and caretakers by setting up an occupational health program for early diagnosis of infection through combined efforts of public health, veterinary medicine, and occupational health experts is suggested. This implies the need for a One Health approach to elephant TB control. This review reveals the need for more research on Mycobacterium tuberculosis complex transmission pathways at the human-animal interface.


Subject(s)
Elephants , Mycobacterium tuberculosis , One Health , Tuberculosis , Animals , Animals, Wild , Elephants/microbiology , Tuberculosis/epidemiology , Tuberculosis/prevention & control , Tuberculosis/veterinary
17.
R Soc Open Sci ; 9(5): 211740, 2022 May.
Article in English | MEDLINE | ID: mdl-35620003

ABSTRACT

Documenting the behavioural repertoire of an animal species is important for understanding that species' natural history. Many behaviours such as mating, parturition and death may be observed only rarely in the wild due to the low frequency of occurrence, short duration and the species' elusiveness. Opportunistic documentation of rare behaviours is therefore valuable for deciphering the behavioural complexity in a species. In this context, digital platforms may serve as useful data sources for studying rare behaviours in animals. Using videos uploaded on YouTube, we document and construct a tentative repertoire of thanatological responses (death-related behaviours) in Asian elephants (Elephas maximus). The most frequently observed thanatological responses included postural changes, guarding/keeping vigil, touching, investigating the carcass, epimeletic behaviours and vocalizations. We also describe some infrequently observed behaviours, including carrying dead calves by adult females, re-assurance-like behaviours and attempts to support dying or dead conspecifics, some of which were only known anecdotally in Asian elephants. Our observations indicate the significance of open-source video data on digital platforms for gaining insights into rarely observed behaviours and support the accumulating evidence for higher cognitive abilities of Asian elephants in the context of comparative thanatology.

18.
Eur J Protistol ; 84: 125881, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35436681

ABSTRACT

Five new Triplumaria species were described from Asian elephants (T. avis, T. cryptopteron, T. takakoae, T. soichii, T. cataphracta) as well as three species described by Timoshenko and Imai (1995), namely T. asiatica, T. nucleocaudata, and T. ovina. The new species have distinct skeletal plate structures: T. avis and T. cryptopteron have the ventral wing, grooves lined with lobes, and posterior fin; T. takakoae, the dorsal oar-shaped stick; T. soichii, the ventral spine and dorsal turn back fringed with lobes; T. cataphracta, two rows of bollard-shaped lobes and two folds composed of a smooth edge and lobes. These eight Triplumaria species have various buccal infraciliary bands. Triplumaria avis, T. cryptopteron, T. asiatica, and T. nucleocaudata have the perivestibular polybrachykinety connected only to the right end of adoral polybrachykinety. Triplumaria takakoae and T. soichii have the perivestibular polybrachykinety that connects to both ends of adoral polybrachykinety and has a loop along the vestibular left slit. Triplumaria cataphracta and T. ovina have the vestibular polybrachykinety connected to the right end of the twisted adoral polybrachykinety. Triplumaria species are highly differentiated ciliates in elephants; 23 of the 28 species described so far have been found in Asian elephants.


Subject(s)
Ciliophora , Elephants , Animals
19.
J Evol Biol ; 35(5): 752-762, 2022 05.
Article in English | MEDLINE | ID: mdl-35470907

ABSTRACT

In species with marked sexual dimorphism, the classic prediction is that the sex which undergoes stronger intrasexual competition ages earlier or quicker. However, more recently, alternative hypotheses have been put forward, showing that this association can be disrupted. Here, we utilize a unique, longitudinal data set of a semi-captive population of Asian elephants (Elephas maximus), a species with marked male-biased intrasexual competition, with males being larger and having shorter lifespans, and investigate whether males show earlier and/or faster body mass ageing than females. We found evidence of sex-specific body mass ageing trajectories: adult males gained weight up to the age of 48 years old, followed by a decrease in body mass until natural death. In contrast, adult females gained body mass with age until a body mass decline in the last year of life. Our study shows sex-specific ageing patterns, with an earlier onset of body mass declines in males than females, which is consistent with the predictions of the classical theory of ageing.


Subject(s)
Elephants , Aging , Animals , Female , Longevity , Male , Reproduction , Sex Characteristics
20.
Viruses ; 14(2)2022 01 24.
Article in English | MEDLINE | ID: mdl-35215824

ABSTRACT

Haemorrhagic disease associated with elephant endotheliotropic herpesvirus (Elephantid herpesvirus, EEHV) infections is the leading cause of death for Asian elephant (Elephas maximus) calves. This study assessed the effect of captive herd management on EEHV shedding, as evidence of latent infection reactivation, focusing on: (1) the influence of social change on the odds of recrudescence; (2) the respective effects of between and within herd moves; and (3) characteristics of recrudescent viral shedding. Trunk and conjunctival swabs (n = 165) were obtained from six elephants at an EAZA-accredited zoo, collected during a period of social stability, and at times of social change. Longitudinal sampling took place at times of moving two bulls out of the collection and one new bull into an adjacent enclosure to the cow herd (between herd moves), and during a period of mixing this new bull with the cow herd to facilitate mating (within herd moves). Quantitative PCR was employed to detect EEHV 1a/b, 4a/b, and EF-1-α (housekeeping gene). Generalised estimating equations determined EEHV recrudescence odds ratios (OR) and relative viral DNA load. Sixteen EEHV 1a/b shedding events occurred, but no EEHV 4a/b was detected. All management-derived social changes promoted recrudescence (social change OR = 3.27, 95% CI = 0.412-26, p = 0.262; and between herd moves OR = 1.6, 95% CI = 0.178-14.4, p = 0.675), though within herd movements posed the most significant increase of EEHV reactivation odds (OR = 6.86, 95% CI = 0.823-57.1, p = 0.075) and demonstrated the strongest relative influence (post hoc Tukey test p = 0.0425). Shedding onset and magnitude ranged from six to 54 days and from 3.59 to 11.09 ΔCts. Differing challenges are associated with between and within herd movements, which can promote recrudescence and should be considered an exposure risk to naïve elephants.


Subject(s)
Animals, Zoo/virology , Elephants/virology , Herpesviridae Infections/veterinary , Herpesviridae/isolation & purification , Herpesviridae/physiology , Animals , Animals, Zoo/physiology , Behavior, Animal , DNA, Viral/genetics , Elephants/physiology , Female , Herpesviridae/classification , Herpesviridae/genetics , Herpesviridae Infections/transmission , Herpesviridae Infections/virology , Longitudinal Studies , Male , Sexual Behavior, Animal , Viral Load , Viral Proteins/genetics , Viral Proteins/metabolism , Virus Shedding
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