Female Asian Elephants Research Articles

Impact of social pressure on the estrus of captive female Asian elephants (Elephas maximus)

Impact of social pressure on the estrus of captive female Asian elephants (Elephas maximus)

Males have more aggressive and less sociable personalities than females in semi-captive Asian elephants

Personality, i.e. consistent between-individual differences in behaviour, has been documented in many species. Yet little is known about how males and females of long-lived, highly social species differ in their measures of personality structure. We investigated sex differences in the mean, variance, and covariance of three previously reported personality traits (Attentiveness, Sociability, Aggressiveness) in 150 female and 107 male Asian elephants (Elephas maximus) from a semi-captive population in Myanmar. These three personality traits were obtained by performing exploratory factor analysis on 28 behavioural items that had been rated by experienced elephant handlers. We found that males scored significantly higher on Aggressiveness and tended to score lower on Sociability than females. However, no sex difference was found in the mean scores of Attentiveness. Variances for the three personality traits did not differ between the sexes, suggesting that male and female elephants share the same range of personality variation. Likewise, trait covariances were similar between the sexes. While both sexes show complex sociality in the wild, female Asian elephants typically live in highly social family units, whereas male elephants’ social bonds are weaker. Males usually form dominance ranks by aggressive interactions, especially during musth. Our results on a large sample of individuals living in their natural environment are thus in agreement with elephant life-histories and parallel the findings of sex differences in other long-lived highly social species with similar life-histories.

Influence of the number of calves and lactating adult females in a herd on the adrenocortical activity of free-ranging Asian elephants

Abstract ContextPhysiological stress has the potential to influence animal population persistence. The endangered Asian elephant (Elephas maximus) is involved in intense conflict with humans in many parts of its range, which likely leads to stress for individuals and groups, with consequences for population survival. Thus, it is important to understand how the elephants’ stress levels are influenced by socio-ecological factors when not directly exposed to human-induced threats, and to use this understanding to improve conservation and management strategies. AimsThe present study was designed to provide baseline information on the link between socio-ecological factors and stress levels of undisturbed populations of elephants. The main aim was to determine the influence of a number of factors – herd size, season, number of calves and adult females present in a herd and their lactational status and body condition – on the adrenocortical activity of free-ranging adult female Asian elephants living in protected forests (without any direct exposure to human-induced threats), by measuring their faecal glucocorticoid metabolite (fGCM) levels. MethodsA total of 145 fresh faecal samples were collected from 123 identified adult female elephants inhabiting Bandipur and Nagarahole National Parks of southern India, between the years 2013 and 2015. fGCM levels were measured by employing a group-specific standardised 11-oxoetiocholanolone enzyme immunoassay (EIA). A generalised linear mixed-effects model (GLMM) was used to assess the influence of socio-ecological factors on fGCM levels of adult female elephants. Key resultsWhen fGCM levels were analysed with a GLMM, the following patterns were observed: fGCM levels were negatively correlated with the number of adult females (herd size) and positively correlated with the number of calves in a herd and active lactational status of an adult female. fGCM levels of adult female elephants were higher during the dry season (February to May) than wet season (August to December) and negatively correlated with body condition scores. ConclusionsAdrenocortical activity of female elephants is significantly influenced by the number of calves and adult females present in the herd, seasonality and lactational status. ImplicationsIt is important to consider the influence of multiple ecological and social correlates when assessing and interpreting the adrenocortical activity of Asian elephants. Our findings highlight the importance of maintaining the social structure of elephants in the wild to avoid detrimental effects on their physiological health. Insights from such assessments could be used to evaluate the stress in elephants that are involved in direct conflicts with humans to take appropriate management decisions for mitigating conflicts.

Social Interactions in Two Groups of Zoo-Housed Adult Female Asian Elephants (Elephas maximus) that Differ in Relatedness.

Simple SummaryThe chance to experience positive social interactions is important for captive animals. The amount of positive or negative social interactions that occur within groups of captive animals can be used to evaluate the welfare of the group and determine how compatible the individuals may, or may not, be. In the wild, elephants live in related, multigenerational herds that consist of mainly mothers, daughters, and their offspring. However, in captivity, they are often kept in groups of unrelated individuals, which could reduce the quality of their social interactions, and thus their welfare. Here, we recorded the social interactions between elephants in two groups of four captive female Asian elephants; in one group, all of the individuals were related to one another, whilst in the other, only two out of four individuals were related. We observed more affiliative (friendly) interactions and fewer aggressive interactions in the all-related group. We also observed elephants freely giving way to others more in the related group, with daughters giving way to their mothers and aunts, which is evidence of an established, family-based rank system that allows them to avoid escalation to aggression. These findings support the recommendation that for optimal welfare, elephants should be managed in multigenerational family herds.Opportunities for positive social interaction are important in captive animals, and social interactions can be used as a welfare indicator. Wild elephants live in related multigenerational herds; however, in captivity they are often managed in less related groups, which could impact the quality of their social interactions, and thus their welfare. Here, we used a limited social network analysis to investigate the social interactions in two groups of four female captive Asian elephants, one of which contained individuals that were all related to one another, whilst the other was a mix of related and unrelated individuals. Data on pairwise social interactions was collected from eight days of video footage using an all-occurrence sampling technique. More affiliative, and fewer agonistic interactions were observed in the related elephant group. Additionally, non-contact displacement was observed at a higher frequency in the related elephant group, which we theorise represents an established functioning hierarchy, avoiding the need for overt aggression over resources. Although kinship is not likely to be the only factor affecting captive elephant social behaviour, these findings support the recommendation that for optimal welfare, elephants should be managed in multigenerational family herds. Evaluations of social interactions such as those conducted here would have wider applicability for aiding the management of any captive social species to identify when groups might be incompatible.

Is There Seasonal Variation In Female Asian Elephant Social Structures In Southern India?

Is There Seasonal Variation In Female Asian Elephant Social Structures In Southern India?

Group size differences may mask underlying similarities in social structure: a comparison of female elephant societies

We studied the social structure of female Asian elephants in southern India and compared it with those of a Sri Lankan population and an African savannah elephant population. While there were social differences between the Asian and African populations using previous methods, all 3 populations showed basic similarities using a newer network method. The discrepancy across analyses partly stemmed from differences in average group size between populations, which variously affected different association and network statistics.

Seasonal variation in female Asian elephant social structure in Nagarahole-Bandipur, southern India

Fission–fusion dynamics allow for individuals to deal with spatiotemporally changing food resources, with groups from a community fusing together when resources are abundant and splitting away when competition for resources is high. Such fission–fusion dynamics are often modulated by seasonal changes in resources. We examined the seasonal variation in group size and social structure of female Asian elephants, which show high fission–fusion dynamics, in a population in southern India. Females in this population form many distinct communities or clans in both the dry and wet seasons. At the population level, females were sighted in larger group sizes and associated with more uncommon females in the dry season. However, when associations among common females were considered, a greater number of stronger associations were observed in the wet season. There were no consistently significant seasonal differences in group sizes or associations at the clan level. Thus, population-level results, obtained by a combination of results from different clans, may sometimes be misleading. Female associations showed some temporal stability, with association indices being moderately correlated across consecutive seasons and years. Interestingly, average group sizes were similar across clans of different sizes, indicating a restriction on group size, possibly due to resource distribution. In spite of this restriction, most clan-mates showed low, non-zero associations amongst themselves rather than very strong associations with a small set of individuals. The resulting fluid rather than fixed groups suggest a benefit to socializing with other clan-mates. Thus, unlike the pattern usually seen, fission–fusion dynamics here is a means to maintain multiple associates under conditions of relatively constant but constrained group size, rather than being a means of increasing or decreasing group size in response to ecological factors.

Is bigger better? The relationship between size and reproduction in female Asian elephants.

The limited availability of resources is predicted to impose trade-offs between growth, reproduction and self-maintenance in animals. However, although some studies have shown that early reproduction suppresses growth, reproduction positively correlates with size in others. We use detailed records from a large population of semi-captive elephants in Myanmar to assess the relationships between size (height and weight), reproduction and survival in female Asian elephants, a species characterized by slow, costly life history. Although female height gain during the growth period overlapped little with reproductive onset in the population, there was large variation in age at first reproduction and only 81% of final weight had been reached by peak age of reproduction at the population level (19years). Those females beginning reproduction early tended to be taller and lighter later in life, although these trends were not significant. We found that taller females were more likely to have reproduced by a given age, but such effects diminished with age, suggesting there may be a size threshold to reproduction which is especially important in young females. Because size was not linked with female survival during reproductive ages, the diminishing effect of height on reproduction with age is unlikely to be due to biased survival of larger females. We conclude that although reproduction may not always impose significant costs on growth, height may be a limiting factor to reproduction in young female Asian elephants, which could have important implications considering their birth rates are low and peak reproduction is young - 19years in this population.

Endocrine correlates of puberty in female Asian elephants (Elephas maximus) at the Pinnawala elephant orphanage, Sri Lanka

BackgroundPrevious studies have established ovarian cycle characteristics of adult Asian elephants using progestagen analyses, but little work has been done on young elephants to determine age at puberty. Demographic studies of wild Asian elephants suggest females give birth at about 12–18 years of age (conceiving at 10–16 years of age based on a 2-year gestation). However, there are a few examples of zoo elephants giving birth at only 5–6 years of age, so they would have started cycling much earlier. This study was carried out at the Pinnawela Elephant Orphanage (PEO) in Sri Lanka, where a herd of >80 captive elephants breeds successfully, resulting in a unique opportunity to monitor hormones and document initiation of ovarian cyclicity in young females, thus contributing to the normative reproductive database for this species.ResultsWe measured serum progestagens in samples collected every 10 days for 18 – 24 months from 11 females (3.5–15 years of age), and found six (5.5 – 12 years of age) already were cycling at study onset. Four females started cycling during the study at 4.5, 5.5, 7.5 and 15 years of age. There were no quantitative or qualitative differences between the first pubertal luteal phase and those of subsequent cycles. Of the 46 ovarian cycles observed, 78% were associated with clear behavioral signs of estrus (heightened bull attentiveness, and willingness of females to be mounted) during the late non-luteal period when progestagens were low. The average body weight at puberty was ~48% of that of adult female elephants at PEO.ConclusionsAsian elephants under human care, including under semi-captive conditions, may reach puberty earlier than those in the wild, perhaps due to better nutrition and reaching a body weight capable of supporting reproductive activity at a younger age. Thus, facilities with bulls need to carefully manage elephants to avoid accidental pregnancies in young females that may be too small to safely carry a pregnancy to term.

Assessment of season-dependent body condition scores in relation to faecal glucocorticoid metabolites in free-ranging Asian elephants.

We studied seasonal and annual changes in visual body condition scores (BCSs), and assessed how these scores were related to levels of faecal glucocorticoid metabolites (fGCMs) in free-ranging Asian elephants (Elephas maximus) in the seasonally dry tropical forests of the Mysore and Nilgiri Elephant Reserves in southern India. We assessed the animals' BCS visually on a scale of 1 to 5; where 1 represents a very thin and 5 represents a very fat elephant. To understand the influence of seasonality on BCS, we sampled the population during dry (n = 398) and wet seasons (n = 255) of 2013 and 2015 while, for annual changes in BCS, we sampled nine free-ranging adult females from different family groups that had been repeatedly sighted over seven years. To evaluate the influence of body condition on fGCM, 307 faecal samples were collected from 261 different elephants and were analysed. As a parameter of adrenocortical activity, and thus stress, fGCM was measured (μg/g) in the ethanol-extracted samples using a group-specific 11-oxoaetiocholanolone EIA (antibody raised against 11-oxoaetiocholanolone-17-CMO:BSA and biotinylated-11-oxoaetiocholanolone as a label). Effect of age and season on BCS in relation to fGCM was also studied. A seasonal shift in BCS was observed as expected, i.e. individuals with low BCS were more frequent during the dry season when compared with the wet season. Concentrations of fGCM were highest in individuals with lowest BCS (BCS 1) and then significantly declined till BCS 3. fGCM levels were almost comparable for BCS 3, 4 and 5. This pattern was more conspicuous in female than in male elephants. Season-dependent BCS, hence, reflect the stress status as measured by fGCM, especially in female Asian elephants. This could be used as an important non-invasive approach to monitor the physiological health of free-ranging elephant populations.

Fission–fusion processes weaken dominance networks of female Asian elephants in a productive habitat

Dominance hierarchies are expected to form in response to socioecological pressures and competitive regimes. We assess dominance relationships among free-ranging female Asian elephants (Elephas maximus) and compare them with those of African savannah elephants (Loxodonta africana), which are known to exhibit age-based dominance hierarchies. Both species are generalist herbivores, however, the Asian population occupies a more productive and climatically stable environment relative to that of the African savannah population. We expected this would lower competition relative to the African taxon, relaxing the need for hierarchy. We tested whether 1) observed dominance interactions among individuals were transitive, 2) outcomes were structured either by age or by social unit according to 4 independent ranking methods, and 3) hierarchy steepness among classes was significant using David's score. Elephas maximus displayed less than a third the number of dominance interactions as observed in L. africana, with statistically insignificant transitivity among individuals. There was weak but significant order as well as steepness among age-classes but no clear order among social units. Loxodonta africana showed significant transitivity among individuals, with significant order and steepness among age-classes and social units. Elephas maximus had a greater proportion of age-reversed dominance outcomes than L. africana. When dominance hierarchies are weak and nonlinear, signals of dominance may have other functions, such as maintaining social exclusivity. We propose that resource dynamics reinforce differences via influence on fission-fusion processes, which we term ecological release. We discuss implications of these findings for conservation and management when animals are spatially constrained.

Management of a Traumatic Wound in a Malnourished Orphan Asian Baby Elephant (Elephas maximus)

The present case report was carried out to evaluate the outcome of traumatic wound in a malnourished orphan elephant calf. A 1.5 month old, female Asian Elephant calf approximate weighing 100 kg, was admitted to the Teaching Veterinary Hospital, Chittagong Veterinary and Animal Sciences University, Bangladesh, with a history of squeezed and trapped in natural tree during foraging, detached from the herd, rescued by nearest forest people and treated by local veterinarian. The baby elephant was dull, depressed, dehydrated and emaciated on clinical examination. A local swelling (65 cm) was noticed on left hind limb(stifle joint) and a circular wound on lateral aspect of the limb where mild discharge was noticed. Gait and posture was not normal. Wound swab, blood and fecal sample were collected and sent to the respective departments. Pyogenic organisms were found in wound swab culture. Blood parameters revealed lower value of TEC, Hg, PCV, glucose and total protein. No parasite or ova were found in fecal sample. The elephant calf was fed with powder milk as 10% of total body weight (10 liters/day at 1 hour interval). Ceftriaxone sodium @ 20 mg/kg bwt along with pain killer ketoprofen @ 3 mg/kg bwt, amino acid solution @20 ml hematinic preparation @10 ml , vitamin ADE preparation @10 ml along with 5% dextrose saline (2liters/day), local application of Dressgel ointment (herbal preparation) and wound dressing with povidone iodine at regular interval as required until healing. The calf revealed improved condition such as more active and alert, improved gait, reduced local swelling and no discharge from the wound. The CBC and serum biochemical parameter was also improved by day 4 while the calf was shifted to Dulahazra safari park, Chokoria, Chittagong.International Journal of Natural Sciences (2015), 5(1) 21-25

Recumbence Behavior in Zoo Elephants: Determination of Patterns and Frequency of Recumbent Rest and Associated Environmental and Social Factors.

Resting behaviors are an essential component of animal welfare but have received little attention in zoological research. African savanna elephant (Loxodonta africana) and Asian elephant (Elephas maximus) rest includes recumbent postures, but no large-scale investigation of African and Asian zoo elephant recumbence has been previously conducted. We used anklets equipped with accelerometers to measure recumbence in 72 adult female African (n = 44) and Asian (n = 28) elephants housed in 40 North American zoos. We collected 344 days of data and determined associations between recumbence and social, housing, management, and demographic factors. African elephants were recumbent less (2.1 hours/day, S.D. = 1.1) than Asian elephants (3.2 hours/day, S.D. = 1.5; P < 0.001). Nearly one-third of elephants were non-recumbent on at least one night, suggesting this is a common behavior. Multi-variable regression models for each species showed that substrate, space, and social variables had the strongest associations with recumbence. In the African model, elephants who spent any amount of time housed on all-hard substrate were recumbent 0.6 hours less per day than those who were never on all-hard substrate, and elephants who experienced an additional acre of outdoor space at night increased their recumbence by 0.48 hours per day. In the Asian model, elephants who spent any amount of time housed on all-soft substrate were recumbent 1.1 hours more per day more than those who were never on all-soft substrate, and elephants who spent any amount of time housed alone were recumbent 0.77 hours more per day than elephants who were never housed alone. Our results draw attention to the significant interspecific difference in the amount of recumbent rest and in the factors affecting recumbence; however, in both species, the influence of flooring substrate is notably important to recumbent rest, and by extension, zoo elephant welfare.

Walking Behavior of Zoo Elephants: Associations between GPS-Measured Daily Walking Distances and Environmental Factors, Social Factors, and Welfare Indicators.

Research with humans and other animals suggests that walking benefits physical health. Perhaps because these links have been demonstrated in other species, it has been suggested that walking is important to elephant welfare, and that zoo elephant exhibits should be designed to allow for more walking. Our study is the first to address this suggestion empirically by measuring the mean daily walking distance of elephants in North American zoos, determining the factors that are associated with variations in walking distance, and testing for associations between walking and welfare indicators. We used anklets equipped with GPS data loggers to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 North American zoos. We collected 259 days of data and determined associations between distance walked and social, housing, management, and demographic factors. Elephants walked an average of 5.3 km/day with no significant difference between species. In our multivariable model, more diverse feeding regimens were correlated with increased walking, and elephants who were fed on a temporally unpredictable feeding schedule walked 1.29 km/day more than elephants fed on a predictable schedule. Distance walked was also positively correlated with an increase in the number of social groupings and negatively correlated with age. We found a small but significant negative correlation between distance walked and nighttime Space Experience, but no other associations between walking distances and exhibit size were found. Finally, distance walked was not related to health or behavioral outcomes including foot health, joint health, body condition, and the performance of stereotypic behavior, suggesting that more research is necessary to determine explicitly how differences in walking may impact elephant welfare.

Urethral Rupture and Leakage Following Prolonged Surgical Removal of Urethral and Bladder Stones by Episiotomy and Urethrotomy in Female Asian Elephant (Elephas Maximus) : A Case Report

Urethral Rupture and Leakage Following Prolonged Surgical Removal of Urethral and Bladder Stones by Episiotomy and Urethrotomy in Female Asian Elephant (Elephas Maximus) : A Case Report

Social significance of trunk use in captive Asian elephants

Tactile behaviour plays an important role in maintaining social relationships in several mammalian species. Touching with the tip of the trunk is a common social behaviour among Asian elephants (Elephas maximus). This is considered an affiliative behaviour; however, few studies have investigated it in detail. Therefore, this study aimed to determine whether this is an affiliative behaviour and whether it has other functions. We directly observed a group of captive female Asian elephants in Thailand. We found that the elephants usually touched each other with their trunks shaped in a U (U-type) or S (S-type) shape. The S-type shape was observed mainly when the elephants touched the lips of other elephants; however, this behaviour was occasionally observed in agonistic or play contexts, where it appeared to be a threat or dominant behaviour, particularly amongst adults. In contrast, the U-type shape was more frequently observed when the elephants were disturbed, where it appeared as a gesture for reassurance. We found that the U-type touch on the genitals may be used for interacting with neonates. Therefore, we suggest that despite the S-type touch having a tactile component, it may be a rare behaviour in Asian elephants that is similar to visual threat displays in other mammals. However, the U-type touch is similar to social grooming behaviour in primates or flipper rubbing in dolphins, and can be used as an indicator of affiliative relationships. Asian elephants change the shape of their trunk while touching others depending on their motivation and the situation, thereby demonstrating that the nuances of trunk use can assist in understanding the social relationships between individuals.

Behavioral changes in female Asian elephants when given access to an outdoor yard overnight

A study was conducted at the Bronx Zoo to determine whether providing elephants with access to an outdoor corral at night had any significant effects on behavior, use of space, and use of a sand corral. Activity budgets for three female Asian elephants were compared when the subjects were housed indoors overnight and when they were given access to an outdoor yard overnight. Observations were recorded via infrared video cameras between the hours of 1900 and 0700 during the months of July-September. Two of the three elephants showed a significant preference for spending time outdoors, whereas, the third elephant spent most of her time indoors. Standing and play behavior increased when the elephants had outdoor access while lying down and feeding behavior decreased. Swaying behavior decreased significantly when the elephants had access to the outdoor yard. The elephants made very little use of a sand-floor stall regardless of whether or not they had access to outdoors. The results of this study, suggest that having access to alternate areas overnight can promote well-being by reducing repetitive behavior and allowing animals to express their preferences for different locations. The relative importance of choice alone vs. the behavioral opportunities provided by choice options for zoo animals is discussed. Zoo Biol. 35:298-303, 2016. © 2016 Wiley Periodicals, Inc.

Cecocolic Intussusception in an Asian Elephant (Elephas maximus) in Sri Lanka Associated with Chronic Hepato-Intestinal Schistosomiasis: A Case Report

A 25 year old female captive Asian elephant weighing approximately 3000kgs died and was subjected to a complete necropsy within 5 hours post mortem. Grossly, the elephant had sub-cutaneous edema, cecocolic intussusception and ascites. Histopathological examination revealed multifocal, granulomatous, portal phlebitis in the liver, multifocal, granulomatous, peri-portal hepatitis with marked portal and perisinusoidal fibrosis, and multifocal granulomatous colitis with intralesional Schistosoma eggs. To our knowledge, this is the first report of cecocolic intussusception in an Asian elephant associated with Schistosoma infection. Int J Appl Sci Biotechnol, Vol 3(4): 744-746

Asian elephants acquire inaccessible food by blowing.

Many animals acquire otherwise inaccessible food with the aid of sticks and occasionally water. As an exception, some reports suggest that elephants manipulate breathing through their trunks to acquire inaccessible food. Here, we report on two female Asian elephants (Elephas maximus) in Kamine Zoo, Japan, who regularly blew to drive food within their reach. We experimentally investigated this behaviour by placing foods in inaccessible places. The elephants blew the food until it came within accessible range. Once the food was within range, the elephants were increasingly less likely to blow as the distance to the food became shorter. One subject manipulated her blowing duration based on food distance: longer when the food was distant. These results suggest that the elephants used their breath to achieve goals: that is, they used it not only to retrieve the food but also to fine-tune the food position for easy grasping. We also observed individual differences in the elephants' aptitude for this technique, which altered the efficiency of food acquisition. Thus, we added a new example of spontaneous behaviour for achieving a goal in animals. The use of breath to drive food is probably unique to elephants, with their dexterous trunks and familiarity with manipulating the act of blowing, which is commonly employed for self-comfort and acoustic communication.

Histological and immunohistochemical characterisation of uterine adenocarcinoma in an Asian elephant (Elephas Maximus).

A 56-year-old nulliparous female Asian elephant (Elephas maximus) living at the zoological garden of Naples (Italy), with a clinical history of recurrent colic, was found in agonal state and humane euthanasia was elected. At necropsy the uterine body was moderately increased in size and the lumen was reduced due to a poorly demarcated and infiltrative neoplasm. Furthermore, multiple, whitish, firm nodules were present in both lungs. Histological examination of the uterine mass revealed epithelial cells arranged in tubular or solid pattern infiltrating the endometrium and the muscular layer. Immunohistochemical examination showed immunoreactivity of neoplastic cells to oestrogen receptors antibody. Pulmonary lesions were histologically and immunohistochemically superimposable to the epithelial uterine neoplasm. A definitive diagnosis of uterine adenocarcinoma with pulmonary metastases was made.