Young Elephants Research Articles

The late Early Pleistocene site of Fuente Nueva-3 (Guadix-Baza Depression, SE Spain): a hyena latrine developed on a quicksand trap for megaherbivores?

AbstractThe late Early Pleistocene archaeological site of Fuente Nueva-3 (FN3), which lies in the Guadix-Baza Depression (SE Spain) and is dated to ~ 1.4 Ma, contributes some of the oldest evidence of hominin presence in Western Europe, including a huge tool assemblage of Oldowan tradition, manuports (i.e., unmodified stones used as percussion tools) and abundant fossils of large mammals, some of which preserve anthropogenic marks related to defleshing, butchering and marrow processing. In addition, there are bones with tooth marks produced by scavenging carnivores. The fertile layers of the FN3 section have been grouped in a lower archaeological level (LAL) and an upper archaeological level (UAL). Both levels preserve abundant skeletal remains and lithic tools. However, the LAL shows a high density of manuports, which suggests that hominin activity was more intense at this level, while the UAL preserves many remains of megaherbivores, particularly proboscideans (Mammuthus meridionalis), and almost all coprolites unearthed from the site, which points to a greater involvement of the giant hyenas (Pachycrocuta brevirostris). In this paper, we (i) test for statistical differences in the composition of the faunal assemblages preserved in the UAL and LAL; and (ii) analyze particle size in the fertile layers of both archaeological levels. Our results show that megaherbivores are comparatively overrepresented in the UAL, specially by young elephants, while other medium-to-large and large-sized ungulates, particularly equids, are more abundant in the LAL, showing a predominance of adult individuals. Concerning the sedimentology, layers 2–3 of the LAL show a predominance of silts and clays, with sands representing a minor fraction. In contrast, layer 5 of the UAL is composed of two-thirds of fine and very fine sands, with the remaining third consisting of silts and clays. These data and the paleoenvironmental reconstruction of layer 5 suggest that it may be interpreted as a paleo-quicksand in which megaherbivores were trapped due to the elevated weight per unit area supported by their feet, and their half-sunken carcasses attracted the scavengers, particularly the hyenas, which fed on these carcasses and defecated in their surroundings.

Low gH/gL (Sub)Species-Specific Antibody Levels Indicate Elephants at Risk of Fatal Elephant Endotheliotropic Herpesvirus Hemorrhagic Disease.

Elephant endotheliotropic herpesviruses (EEHVs), of which eleven (sub)species are currently distinguished, infect either Asian (Elephas maximus) or African elephants (Loxodonta species). While all adult elephants are latently infected with at least one EEHV (sub)species, young elephants, specifically those with low to non-detectable EEHV-specific antibody levels, may develop fatal hemorrhagic disease (EEHV-HD) upon infection. However, animals with high antibody levels against EEHV(1A) gB, an immunodominant antigen recognized by antibodies elicited against multiple (sub)species, may also occasionally succumb to EEHV-HD. To better define which animals are at risk of EEHV-HD, gB and gH/gL ELISAs were developed for each of the Asian elephant EEHV subspecies and assessed using 396 sera from 164 Asian elephants from European zoos. Antibody levels measured against gB of different (sub)species correlated strongly with one another, suggesting high cross-reactivity. Antibody levels against gH/gL of different subspecies were far less correlated and allowed differentiation between these (sub)species. Importantly, while high gB-specific antibody levels were detected in the sera of several EEHV-HD fatalities, all fatalities (n = 23) had low antibody levels against gH/gL of the subspecies causing disease. Overall, our data indicate that (sub)species-specific gH/gL ELISAs can be used to identify animals at risk of EEHV-HD when infected with a particular EEHV (sub)species.

A culture of aggression: the Gorongosa elephants' enduring legacy of war

Humans have hunted elephants since the Palaeolithic era and, as cunning predators, have likely helped shape the animals’ sophisticated defensive behaviour. In recent centuries, the use of modern weapons in targeted mass killings has resulted in signs of post-traumatic stress disorder (PTSD) in elephants, including heightened aggression and impaired decision- making. During Mozambique’s long civil war (1977–1992), 90% of the elephants of Gorongosa National Park were killed. More than a quarter of a century after the end of hostilities aggression towards vehicles by elephant families is an enduring legacy. This study found that females and entire families were more likely to charge when vehicles were in close proximity (<~80 m) and on, rather than off, the roads. Although aggression was primarily initiated and led by older adult females, most charges involved mobbing by entire families, including calves. Some individuals engaged in idiosyncratic defensive behaviours, while some families exhibited distinctive group manoeuvres that appeared to form traditions, indicating that young elephants were acquiring their defensive responses within this social context. We argue that the aggressive behaviour of the Gorongosa elephants is a response to the traumatic events of the civil war and that the observed patterns of behaviour are transmitted within and across groups, giving rise to a culturally learned behavioural variant that has persisted over time and generations. Given rapid environmental change, increasing contact between elephants and people, and the extreme losses caused by poaching and armed conflict, a better understanding of the role that culture plays in the response of elephants to people is urgently needed. Conservation and management strategies may have to be adapted to meet the changing cultures of specific elephant populations.

Combining Camera Trap Data and Environmental Data to Estimate the Effects of Environmental Gradients on Abundance of the Asian Elephant Elephas maximus in Cambodia

Asian elephant (Elephas maximus) populations in Cambodia are currently declining, and the effect of environmental degradation on the abundance and health of elephants is poorly understood. We used camera trap data from 42 locations between 2016 to 2020 in the southern Cardamom Mountains to investigate the impact of environmental degradation on the abundance and condition of Asian elephants. Camera trap data were organized using CameraSweet software to retrieve both number of individuals and their condition. For a number of individuals, we defined independent captures spatially and temporally. To assess condition, we created a visual scoring system based on past research (Wemmer et al. 2006, Fernando et al. 2009, Morfeld et al. 2014, Wijeyamohan et al. 2014, Morfeld et al. 2016, Schiffmann et al. 2020). This scoring system relies on visual assessment of the muscle and fat in relation to the pelvis, ribs, and back bone. To validate this subjective scoring system, two scorers reviewed elephant captures by using 10 reference photos and then reviewing each other’s assessment in the first five images showing the elephant's body condition. This method minimizes subjective assessment from two scorers. Environmental variables (Suppl. material 1) such as distance to forest edge, forest integrity index, elevation, global human settlements, distance to road, distance to river, night light and forest cover were obtained, then reclassified in ArcGIS to a common 1 km grid. We implemented hierarchical N-mixture models to investigate the impacts of environmental variables on abundance and used cumulative link models to investigate the impact of the same environmental variables on condition. We found that Asian elephant abundance exhibited a significant positive relationship with distance to forest edges, where abundance was greater further away from a forest edge. We found that body condition score exhibited the relationship with forest cover and Forest Landscape Integrity Index, which suggested that grassland and less dense forest support better condition. Moreover, males exhibited significantly higher scores for body condition than females, while babies, juveniles, and subadults all exhibited lower body condition scores compared to adults. The significantly lower body condition of young elephants is concerning and suggests that conservation managers in the region should prioritize environmental conditions that support young elephant health. Our results identify key environmental variables that appear to promote Asian elephant abundance and health in the Cardamom Mountains, thus informing relevant conservation actions to support this endangered species in Cambodia and beyond.

Sleeping while diving: seals at sea drift in and out of sleep at depth

In mammals, sleep is critical and ubiquitous. However, in marine mammals that spend months or entire lifetimes at sea, sleep can limit access to air and foraging opportunities and leave animals vulnerable to predation. Large, deep-diving northern elephant seals (Mirounga angustirostris) travel thousands of kilometers and spend up to 7 months at sea in search of food. We posited that combined demands to feed and avoid predators would strongly restrict aquatic sleep in seals. We built a portable, non-invasive system to simultaneously monitor electroencephalogram (EEG), electrocardiogram (ECG), three-dimensional motion, and swimming behavior. EEG activity of 13 young (< 3-years-old) female northern elephant seals (N = 5 in the lab, N = 8 in the wild [N = 3 at sea]) revealed that total sleep time was indeed strongly restricted at sea compared to on land (> 6-fold difference; 10.8 ± 3.0 h/day on land, 1.7 ± 0.7 h/day at sea). Seals at sea slept during short naps (< 20 min) while resting on the ocean floor (64-249 m deep) or drifting through the water column (82-377 m deep). REM sleep in mammals co-occurs with sleep paralysis. Our data support the presence of sleep paralysis through a persistent supine inversion (belly-up posture) whenever the seal was in REM (100% of REM sleep in the open ocean). Unexpectedly, elephant seals at sea exhibited a large proportion of REM sleep (29.1 ± 4.3% of at-sea total sleep time), compared to aquatic sleep in captive Caspian seals, harp seals, walruses, and fur seals (11%, 6%, 5%, and 1% respectively). This suggests that sleep at depth allows seals to drift safely in and out of sleep paralysis. However, time for sleep is limited by near-constant foraging to support high energetic demands due to their large body size. The extreme flexibility in sleep duration exhibited by northern elephant seals is unprecedented among mammals – approaching that which is observed in migrating birds. These insights into sleep for a large, highly mobile marine mammal can contribute to our understanding of sleep’s function and pathology across mammals, including humans. Funding: NSF Graduate Resesarch Fellowship, Laurel Clark Sea to Space Physiology Research Grant, ARCS Fellowship, Sooy Graduate Fellowship, National Geographic Early Career Grant, Special Research Grant – UC Santa Cruz, Joint Industry Project (JIP2207-23) [DPC], Office of Naval Research (Grants # N00014-08-1-1195 [DPC], N00014-18-1-2822 [DPC], N00014-00-1-0880 [DPC], N00014-03-1-0651 [DPC], N00014-08-1-1195 [DPC], N00014-20-1-2762 [TMW], N00014-19-1-2178 [TMW]) This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The Gut Microbiota of Young Asian Elephants with Different Milk-Containing Diets.

Evaluating the association between milk-containing diets and the microbiomes of young Asian elephants could assist establishing optimal breast milk supplementation to improve offspring survival rates. The microbiomes of young Asian elephants on different milk-containing diets (elephant milk only, elephant milk-plant mixed feed, and goat milk-plant mixed feed) were investigated using high-throughput sequencing of 16S rRNA genes and phylogenetic analysis. Microbial diversity was lower in the elephant milk-only diet group, with a high abundance of Proteobacteria compared to the mixed-feed diet groups. Firmicutes and Bacteroidetes were dominant in all groups. Spirochaetae, Lachnospiraceae, and Rikenellaceae were abundant in the elephant milk-plant mixed-feed diet group, and Prevotellaceae was abundant in the goat milk-plant mixed-feed diet group. Membrane transport and cell motility metabolic pathways were significantly enriched in the elephant milk-plant mixed-feed diet group, whereas amino acid metabolism and signal transduction pathways were significantly enriched in the goat milk-plant mixed-feed diet group. The intestinal microbial community composition and associated functions varied significantly between diets. The results suggest that goat milk is not suitable for young elephants. Furthermore, we provide new research methods and directions regarding milk source evaluation to improve elephant survival, wellbeing, and conservation.

EEHV1A glycoprotein B subunit vaccine elicits humoral and cell-mediated immune responses in mice

Asian elephants are an endangered species facing many threats, including severe hemorrhagic disease (HD) caused by the elephant endotheliotropic herpesvirus (EEHV). EEHV-HD is the leading cause of death in captive juvenile Asian elephants in North America and Europe, and also affects elephants in their natural range countries. Significant challenges exist for successful treatment of EEHV-HD, which include timely recognition of disease onset and limited availability of highly effective treatment options. To address this problem, our goal is to prevent lethal disease in young elephants by developing a vaccine that elicits robust and durable humoral and cell-mediated immunity against EEHV. EEHV glycoprotein B (gB) is a major target for cellular and humoral immunity in elephants previously exposed to EEHV. Therefore, we generated a vaccine containing recombinant EEHV1A gB together with a liposome formulated TLR-4 and saponin combination adjuvant (SLA-LSQ). CD-1 mice that received one or two vaccinations with the vaccine elicited significant anti-gB antibody and polyfunctional CD4+ and CD8+ T cell responses, while no adverse effects of vaccination were observed. Overall, our findings demonstrate that an adjuvanted gB protein subunit vaccine stimulates robust humoral and cell-mediated immune responses and supports its potential use in elephants.

Young elephants in a large herd maintain high levels of elephant endotheliotropic herpesvirus-specific antibodies and do not succumb to fatal haemorrhagic disease.

Elephant endotheliotropic herpesviruses (EEHVs) have co-existed with elephants for millions of years, yet may cause fatal haemorrhagic disease (EEHV-HD), typically in elephants between 1 and 10 years of age. EEHV is omnipresent in (sub)adult elephants, and young elephants with low EEHV-specific antibody levels are at risk for EEHV-HD, suggesting that fatal disease may occur due to an insufficiently controlled primary infection. To further address this hypothesis, sera of three large elephant cohorts were subjected to a multiple EEHV species ELISA: (I) 96 Asian elephants between 0 and 57 years, including 13 EEHV-HD fatalities, from European zoo herds typically sized five to six elephants, (II) a herd of 64 orphaned elephants aged 0-15 years at the Elephant Transit Home in Sri Lanka and (III) 31 elephants aged 8-63 years, part of a large herd of 93 elephants at Pinnawala Elephant Orphanage, Sri Lanka. All Sri Lankan elephants showed high EEHV-specific antibody levels regardless of their age. While antibody levels of most European zoo elephants were comparable to those of Sri Lankan elephants, the average antibody level of the European juveniles (1-5 years of age) was significantly lower than those of age-matched Sri Lankan individuals. Moreover, the European juveniles showed a gradual decrease between 1 and 4 years of age, to be attributed to waning maternal antibodies. Maintenance of high levels of antibodies in spite of waning maternal antibodies in young Sri Lankan elephants is likely due to the larger herd size that increases the likelihood of contact with EEHV-shedding elephants. Together with the observation that low levels of EEHV-specific antibodies correlate with increased numbers of EEHV-HD fatalities, these results suggest that infection in presence of high maternal antibody levels may protect calves from developing EEHV-HD, while at the same time activating an immune response protective in future encounters with this virus.

Age‐Specific differences in Asian elephant defecation, dung decay, detection and their implication for dung count

AbstractIn vertebrate population estimation, converting faecal density into animal density requires information on the faecal production rate, decay rate and faecal density. Differences in the above factors for long‐lived species across age classes were not evaluated. We have evaluated these factors associated with the dung count of Asian elephants (Elephas maximus) in the tropical forest of southern India.The defecation rate of elephants was determined in semi‐wild elephants at the Mudumalai elephant camp. The relationship between dung bolus diameter and age was determined to estimate the age of the elephant. The total and age‐specific elephant density based on dung bolus diameter was estimated. A total of 24 transect lines of 2–4 km (125 km) were sampled in the study area. An experiment was conducted to assess the detection probability across the age classes of dung piles. The dung decay rates across age classes and seasons were determined by marking fresh dung piles (n = 1551). The dung‐based age structure assessment and its limitations were evaluated.The mean defecation rate was 13.51 ± 0.51 per day. The defecation rate was significantly lower for the younger age class and increased with the age of elephants. Defecation rates were significantly lower in the wet season than in the dry. The dung bolus diameter positively increased with the age of elephants, and the growth curve can be used to predict the age and age structure of elephant populations.The disparity in the dung production rate results in the lower availability of younger age class (juvenile and calf) dung in the transect for counting, which results in lower dung abundance. The detection probability of dung piles of younger age classes was low (0.58). The survival rates of dung piles of younger age classes were lower and increased with the age of elephants in the wet season. Hence, the demographic assessment of the population based on dung needs to consider age‐specific differences in dung production, decay and detection probability. Although the demographic assessment using dung provides insight into population age structure, it has limitations in predicting age structure for young elephants.

Doran H. Ross: His Fabulous Fowler Years

Doran H. Ross: His Fabulous Fowler Years

Exposure to Toxoplasma gondii in Asian Elephants (Elephas maximus indicus) in Thailand.

Toxoplasma gondii is the causative agent of toxoplasmosis in humans and various animal species worldwide. In Thailand, seroprevalence studies on T. gondii have focused on domestic animals, and information on infections in Asian elephants (Elephas maximus indicus) is scarce. This study was conducted to determine the seroprevalence of T. gondii infection in archival sera collected from 268 elephants living in Thailand. The serum samples were analyzed for anti-T. gondii immunoglobulin G antibodies using the latex agglutination test (LAT) and indirect enzyme-linked immunosorbent assay (iELISA) based on T. gondii lysate antigen (TLA-iELISA) and recombinant T. gondii dense granular antigen 8 protein (TgGRA8-iELISA). The prevalence of antibodies against T. gondii was 45.1% (121/268), 40.7% (109/268), and 44.4% (119/268) using LAT, TLA-iELISA, and TgGRA8-iELISA, respectively. Young elephants had a higher seropositivity rate than elephants aged >40 years (odds ratio = 6.6; p < 0.001; 95% confidence interval: 2.9–15.4). When LAT was used as the reference, TLA-iELISA and TgGRA8-iELISA showed a substantial (κ = 0.69) and moderate (κ = 0.42) agreement, respectively. Although our findings suggest the widespread exposure of Asian elephants to T. gondii in Thailand, the source of infection was not investigated. Therefore, investigation of the predisposing factors associated with toxoplasmosis is necessary to identify the potential risk factors for infection.

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.

Patterns of serum immune biomarkers during elephant endotheliotropic herpesvirus viremia in Asian and African elephants.

Hemorrhagic disease (HD) caused by a group of elephant endotheliotropic herpesviruses (EEHV) is one of the leading causes of death for young elephants in human care. These viruses are widespread and typically persist latently in adult elephants with no negative effects; however, in juvenile Asian and more recently young African elephants, the onset of disease can be rapid and the mortality rate high. Measuring biomarkers associated with the immune response could be beneficial to understanding underlying disease processes, as well as the management of infection and HD. The goal of this study was to measure acute phase proteins and cytokines in serum collected from elephants infected with EEHV (13 Asian and 1 African) and compare concentrations according to presence, severity and outcome of disease. Serum amyloid A (SAA) and haptoglobin (HP) were higher in elephants with EEHV viremia than those without; concentrations increased with increasing viral load, and were higher in fatal cases compared to those that survived. In Asian elephants, SAA was also higher during EEHV1 viremia compared to EEHV5. Cytokine concentrations were typically low, and no statistical differences existed between groups. However, in individuals with detectable levels, longitudinal profiles indicated changes in tumor necrosis factor alpha (TNF-α) and interleukin-2 (IL-2) that may reflect an immune response to EEHV infection. However, the overall low concentrations detected using previously validated assays do not support the presence of a ‘cytokine storm’ and suggest more work is needed to understand if sub-optimal immune responses could be involved in disease progression. These results highlight the potential benefit of measuring circulating biomarker concentrations, such as APPs and cytokines, to improve our understanding of EEHV viremia and HD, assist with monitoring the progression of disease and determining the impact of interventions.

Primary Infection May Be an Underlying Factor Contributing to Lethal Hemorrhagic Disease Caused by Elephant Endotheliotropic Herpesvirus 3 in African Elephants (Loxodonta africana).

ABSTRACTDistinct but related species of elephant endotheliotropic herpesviruses (EEHVs) circulate within Asian and African elephant populations. Primary infection with EEHVs endemic among Asian elephants can cause clinical illness and lethal EEHV hemorrhagic disease (EEHV-HD). The degree to which this occurs among African elephants has not been fully established. Recent cases of EEHV-HD caused by the EEHV3 species in African elephants housed in North American zoos has heightened concern about the susceptibility of this elephant species to EEHV-HD. In this study, we utilize the luciferase immunoprecipitation system (LIPS) to generate a serological assay specific for EEHV3 in African elephants by detecting antibodies against the EEHV3 E34 protein. The results showed that the majority of tested elephants from four separate and genetically unrelated herds, including five elephants that survived clinical illness associated with EEHV3, were positive for prior infection with EEHV3. However, African elephants who succumbed to EEHV3-HD were seronegative for EEHV3 prior to lethal infection. This supports the hypothesis that fatal EEHV-HD caused by EEHV3 is associated with primary infection rather than reactivation of latent virus. Lastly, we observed that African elephants, like Asian elephants, acquire abundant anti-EEHV antibodies prenatally and that anti-EEHV3 specific antibodies were either never detected or declined to undetectable levels in those animals that died from lethal disease following EEHV3 infection.IMPORTANCE Prior to 2019, only five cases of clinical disease from EEHV infection among African elephants had been documented. Since 2019, there have been at least seven EEHV-HD cases in North American zoos, resulting in three fatalities, all associated with EEHV3. Evidence is accumulating to suggest that EEHV-associated clinical illness and death among Asian elephants is due to primary infection and may be associated with waning anti-EEHV antibody levels in young elephants. The development of the EEHV3 serological test described in this study enabled us to confirm that similar dynamics may be contributing to EEHV-HD in African elephants. The ability to screen for EEHV immune status in African elephant calves will have a major impact on managing captive African elephant herds and will provide new tools for investigating and understanding EEHV in wild populations.

Elephant Endotheliotropic Herpesvirus Is Omnipresent in Elephants in European Zoos and an Asian Elephant Range Country.

Elephant endotheliotropic herpesviruses (EEHVs) may cause acute, often lethal, hemorrhagic disease (EEHV-HD) in young elephants. Prevalence of EEHV in different elephant populations is still largely unknown. In order to improve diagnostic tools for the detection of EEHV infections and to obtain insight into its spread among elephants, we developed novel ELISAs based on EEHV1A gB and gH/gL. Performance of the ELISAs was assessed using sera from 41 European zoo elephants and 69 semi-captive elephants from Laos, one of the Asian elephant range countries. Sera from all (sub)adult animals tested (≥5 years of age) showed high reactivity with both gB and gH/gL, indicating that EEHV prevalence has been highly underestimated so far. Reactivity towards the antigens was generally lower for sera of juvenile animals (1 > 5 years). Only one (juvenile) animal, which was sampled directly after succumbing to EEHV-HD, was found to be seronegative for EEHV. The two other EEHV-HD cases tested showed low antibody levels, suggesting that all three cases died upon a primary EEHV infection. In conclusion, our study suggests that essentially all (semi-)captive (sub)adult elephants in European zoos and in Laos carry EEHV, and that young elephants with low antibody levels are at risk of dying from EEHV-HD.

The occurrence of elephant endotheliotropic herpesvirus infection in wild and captive Asian elephants in Thailand: Investigation based on viral DNA and host antibody.

Background and Aim:Elephant endotheliotropic herpesvirus (EEHV) is a serious disease, threatening the life of young elephants. Many elephants have been infected with no clinical signs and may serve as carriers spreading this disease. It is important to monitor the disease through clinical signs and molecular diagnosis. In this study we investigated the occurrence of EEHV and the efficiency of different techniques used to monitor EEHV infection in various samples and populations of Asian elephants.Materials and Methods:Blood and trunk swabs were collected from live elephants, while visceral organs (lung, digestive tract, spleen, lymph nodes, and kidney) were collected from dead elephants. EEHV was detected by polymerase chain reaction (PCR) in whole blood, trunk swabs, and visceral organs as samples, while elephant anti-EEHV immunoglobulin G (IgG) in serum was detected by enzyme-linked immunosorbent assay (ELISA). A total of 162 samples were analyzed in this study: 129 from healthy, 26 from dead, and 7 from sick elephants.Results:The present study showed that the overall incidence of EEHV was 40.1% (n=65/162). Approximately 46.2% (n=12/26) and 85.7% (n=6/7) of dead and sick elephants were positive for EEHV by PCR, respectively. All sick elephants that were young and affected by EEHV clinical disease tested negative for the IgG antibody ELISA, suggesting primary EEHV infection in this group. In addition, 2.3% (n=3/129) of subclinical infections were detected using PCR, and trunk swab samples showed slightly higher sensitivity (5.3%, n=2/38) to detect EEHV than whole blood (1.2%, n=1/84). As many as, 48.4% (n=44/91) of healthy elephants were EEHV seropositive (ELISA-positive), suggesting that many elephants in Thailand had previously been infected. Overall, 30% of dead wild elephants had been infected with EEHV (n=3/10). Moreover, statistical analysis revealed no significant differences in the EEHV detection rate between different age groups or sexes (p>0.05).Conclusion:PCR is better than ELISA to detect EEHV active infection in dead/sick elephants and to monitor EEHV in young elephants. ELISA is suitable for detecting previous EEHV infection and carriers, particularly adults. Theoretically, we could use both PCR and ELISA to increase the sensitivity of testing, along with observing abnormal behavior to efficiently monitor this disease. Identification of EEHV carriers within elephant populations is important to prevent transmission to healthy individuals, especially young elephants with high mortality from EEHV. This is the first report from Thailand regarding EEHV infection in wild elephants, showing the importance of preventing disease transmission between captive and wild elephants.

Social and environmental impacts on sleep in captive Asian elephants (Elephas maximus).

Modern zoos strive to improve standards of animal management, husbandry and welfare of their animals as part of a continual evaluation process. Elephants (Elephantidae) have received particular attention in recent years due to the challenge of providing environments which promote natural behavior and opportunities for social interaction. A number of measures have been proposed to measure wellbeing, with sleep quality increasingly being used. Sleep is a vital aspect of life for cell replenishment as well as optimal development of young. Sleep deprivation can lead to immunosuppression and illness; therefore animal managers have a responsibility to ensure they reduce the potential for disturbance through noise, light, or other environmental factors. The social environment also plays an essential role in wellbeing, particularly for species that live in multi-generational family units. In this study the nocturnal behavior of a multi-generational captive herd was observed to determine impacts of husbandry changes on sleep duration and bout length (measured as recumbent rest). As expected, average total duration of sleep was higher in younger elephants and rates were comparable to those reported in other studies of Asian elephants. Overnight access to an outdoor paddock in warmer weather increased overall average bout length of sleep in the herd. Average total duration of sleep also increased for the herd following the movement of an unrelated adult female who had previously shown weak bonds with other herd members. This indicates that social compatibility is a vital component of elephant welfare, impacting not only behavioral interactions but sleep quality and duration.

Freud Does Disney

Dumbo tells a coming of age story about a young elephant who must gain psychological independence from his mother; Fantasia consists of eight episodes on various subjects, but they are strung together with the image of the conductor, Leopold Stokowski, and his (famous) hands. Two of the episodes (Nutcracker Suite and Night on Bald Mountain) dramatize the use of hands in controlling the actions of others. I elaborate on these issues using the psychoanalytic work of Erik Erikson, Ernst Kris, John Bowlby, and Norman Holland and introduce material on the neuropsychology of motor control.

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.

Evolutionary significance of maternal kinship in a long-lived mammal.

Preferential treatment of kin is widespread across social species and is considered a central prerequisite to the evolution of cooperation through kin selection. Though it is well known that, among most social mammals, females will remain within their natal group and often bias social behaviour towards female maternal kin, less is known about the fitness consequences of these relationships. We test the fitness benefits of living with maternal sisters, measured by age-specific female reproduction, using an unusually large database of a semi-captive Asian elephant ( Elephas maximus) population. This study system is particularly valuable to an exploration of reproductive trends in a long-lived mammal, because it includes life-history data that span multiple generations, enabling a study of the effects of kinship across a female's lifespan. We find that living near a sister significantly increased the likelihood of annual reproduction among young female elephants, and this effect was strongest when living near a sister 0-5 years younger. Our results show that fitness benefits gained from relationships with kin are age-specific, establish the basis necessary for the formation and maintenance of close social relationships with female kin, and highlight the adaptive importance of matriliny in a long-lived mammal. This article is part of the theme issue 'The evolution of female-biased kinship in humans and other mammals'.