Clinical characteristics of elephant endotheliotropic herpesvirus (EEHV) cases in Asian elephants (Elephas maximus) in Thailand during 2006–2019

BackgroundElephant endotheliotropic herpesvirus causes a hemorrhagic disease (EEHV-HD) that is a major cause of death in juvenile Asian elephants with EEHV1 and EEHV4 being the most prevalent.AimTo perform a retrospective clinical data analysis.MethodsRecords of a total of 103 cases in Thailand confirmed by polymerase chain reaction (PCR) on blood and/or tissue samples.ResultsThe severity of clinical signs varied among EEHV subtypes. EEHV1A was the most prevalent with 58%, followed by EEHV4 with 34%, EEHV1B with 5.8% and EEHV1&4 co-infection with 1.9%. Overall case fatality rate was 66%. When compared among subtypes, 100% case fatality rate was associated with EEHV1&4 co-infection, 83% with EEHV1B, 75% with EEHV1A, and the lowest at 40% for EEHV4. Calves 2- to 4-year old were in the highest age risk group and exhibited more severe clinical signs with the highest mortality. Majority of cases were found in weaned or trained claves and higher number of cases were observed in rainy season. A gender predilection could not be demonstrated. Severely affected elephants presented with thrombocytopenia, depletion of monocytes, lymphocytes and heterophils, a monocyte:heterophil (M:H) ratio lower than 2.37, hypoproteinemia (both albumin and globulin), severe grade of heterophil toxicity, and low red blood cell counts and pack cell volumes. Survival was not affected by antiviral drug treatment in the severely compromised animals.ConclusionEarly detection by laboratory testing and aggressive application of therapies comprising of supportive and anti-viral treatment can improve survival outcomes of this disease.     

New challenges facing traditional nature reserves: Asian elephant (Elephas maximus) conservation in China

Traditional conservation strategies can effectively preserve biodiversity within nature reserves, but may fail to mitigate the conflicts between rural development and wildlife conservation. This paper discusses the magnitude of the conflict and its development over time, focusing on elephant conservation and land resource management within and around nature reserves. We suggest that regulations alone can satisfy neither the demands to maintain biodiversity and ecosystem services nor the demands to achieve human welfare. More innovative tools such as informed land‐use planning and integrated conservation development projects are called for to reduce the agricultural interface with elephant range, and therefore to alleviate the damage caused by the conflict.     

Personality and behavioral changes in Asian elephants (Elephas maximus) following the death of herd members

Elephants are highly social beings with complex individual personalities. We know that elephants have a general interest in death, investigating carcasses, not just limited to kin; however, research does not explore in depth whether individuals change their behavior or personality following traumatic events, such as the death of a conspecific. Within a captive herd of Asian elephants (Elephas maximus) housed at Chester Zoo, UK, we measured social behavior and proximity and personality using the Ten-Item Personality Inventory, and found age-related and relationship-related changes in both behavior and personality following the deaths of herd members. Overall, the herd spent less time socializing and engaging in affiliative behaviors following the death of the adult female when compared to baseline data, yet spent more time engaging in these behaviors after the death of two calves. The death of the central female had a dramatic impact on her infant calf, resulting in increasingly withdrawn behavior, yet had the opposite effect on her adult daughter, who subsequently established a more integrated role within the herd. Emotional Stability fell in the motherless calf but rose in an adult female, who had lost her adult daughter, but had a new calf to care for. We suggest that the greater impact on the behavior and personality of surviving herd members following the deaths of calves, compared to an adult member, attests to the significance of the unifying role played by calves within an elephant herd.     

Biological and environmental factors associated with the detection of elephant endotheliotropic herpesvirus in Asian elephants (Elephas maximus) in Thailand

Elephant endotheliotropic herpesvirus (EEHV) infection is one of the most common diseases in young elephants, causing severe fatal hemorrhagic disease. Subclinical infection was previously described; however, information about the factors associated with virus shedding and reactivation were scarce. To identify the biological and environmental factors related with EEHV detection, blood and oral swab samples were collected from nine captive Asian elephants in Thailand for one year and tested for EEHV presence using real-time PCR. Data including hematological values, management, environmental temperature, and serum cortisol levels were also recorded and analyzed. Results showed that the viral detection frequency ranged from 0–25%. The highest detection frequency was found in the two youngest elephants, aged less than 15 years. Three types of viruses, EEHV1, EEHV4, and EEHV5, were found in this study, which also detected mixed infection in five elephants. Additionally, the study found that sample type, changes in hematological values, management and health issues, and serum cortisol levels were not associated with herpesvirus detection in the elephants. However, EEHV detection percentage was significantly increased in the summer (mid-Feb to mid-May), possibly due to body fitness reduction from food source limitation and low nutrient content. To obtain a broad aspect of EEHV management, long-term EEHV monitoring is highly recommended in every captive elephant herd.     

Effect of feeding different levels of wheat roti on nutrient utilization and blood metabolite profile in semi‐captive Asian elephants (Elephas maximus)

This experiment was conducted to study the effect of different levels of wheat roti (WR) on nutrient utilization and blood metabolites in Asian elephants fed roughages ad libitum. Nine (3 M, 6 F) Asian elephants (14–52 years of age, 1909–3968 kg BW) were used in an experiment based on replicated Latin square design. Animals in each group (n = 3) were assigned to one of the three dietary treatments in a manner that animals in all the three groups were exposed to all the three treatments in three different periods. Each feeding trial comprised 30 days (25 days of adaptation and 5 days collection period). The amount of WR fed to the elephants was 0.18, 0.12 and 0.06% of BW in groups I, II and III, respectively. They were allowed to forage in the nearby forests for 6 h/day and to bathe for 2 h/day. The animals had ad libitum access to cut Rohini (Mallotus philippensis) trees in their night shelter. Intake and apparent digestibility of dry matter (DM), crude protein (CP), gross energy (GE), Ca, P, Fe, Cu and Zn were measured. Feed consumption was not significantly different among the groups. Significant (p < 0.01) decrease in digestibility of DM and GE and blood glucose concentration was observed with decreased level of WR in the diet. Feeding of WR at 0.06% of BW supplied adequate amount of DE, CP, Ca, P, Fe, Cu and Zn to meet requirement for adult maintenance. Feeding of WR in excess of 0.06% of BW supplied DE in excess of requirement, increased blood glucose concentration which may cause obesity and other associated health problems. It was concluded that the amount of WR should be restricted to 0.06% of BW in the diet of captive Asian elephants.     

基于微卫星标记的中国斑翅山鹑遗传多样性及遗传结构分析

斑翅山鹑(Perdix dauuricae)是具有很高经济价值的猎用禽.为了获得其群体遗传多样性及遗传变异信息,为我国斑翅山鹑进一步有效保护和合理利用提供科学依据,本研究共采用了8个微卫星标记位点对分布于我国北方的斑翅山鹑23个地理种群285个个体进行了群体遗传多样性及遗传结构分析.结果表明,我国斑翅山鹑为遗传多样性较丰富的群体,且每一群体均表现出较高的遗传多样性,其中柴达木盆地地区的种群拥有最高的遗传多样性.遗传分化分析显示组间及组内种群间均表现为遗传分化显著,遗传分化系数(FST)值表明大部分种群间表现出显著的遗传分化.系统树构建和贝叶斯聚类分析结果均显示斑翅山鹑23个地理种群被分化为明显的两个组群.另外,通过BOTTLENECK对各地理种群的分析显示斑翅山鹁种群曾经历过近期瓶颈效应.本研究结果表明,柴达木盆地地区种群、华北平原地区种群、静宁种群、张家川种群以及六盘山地区种群应予以相应关注,以保证有足够的种群大小来保持这些种群的遗传多样性.