Hand-raising Orphan Asian Elephants
Chapter 7: Growth & Behavioral Development
By Susan K. Mikota and Vijitha Perera
​
With contributions from Bhaskar Choudhury and Willem Schaftenaar
​
Sections in this chapter include the following:
​
-
Developmental stages
-
Allo-parenting
-
Monitoring growth
-
Coprophagy
-
Weaning
-
Behavioral development
-
Play and exercise
-
Socialization
-
Enrichment
​​
![Figure 7.1 Orphan calf bonding with his caregiver in Vietnam.jpeg](https://static.wixstatic.com/media/ec3724_6cb912744e20410bb0730a3e6e1a080c~mv2.jpeg/v1/crop/x_0,y_673,w_3456,h_3344/fill/w_351,h_339,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_1%20Orphan%20calf%20bonding%20with%20his%20caregiver%20in%20Vietnam.jpeg)
​
Developmental Stages
​
Calf/newborn/infant/neonate, juvenile, subadult, and adult are the terms used to describe age categories of elephants. However, there is no one standard terminology to clearly differentiate these different age-size classes. Fernando reviews some of the systems that have been used and presents an alternative method based on calf size relative to an adult female elephant (Fernando et al., 2020).
In Sri Lanka, at the Elephant Transit Home, where orphaned elephant calves undergo rehabilitation, young elephants are categorized as follows: <1 year are infants; >1 year to 4 years are calves; >4 years to 8 years are juveniles; and 8 to 15 years are sub-adults (Vijitha Perera). At the Center for Wildlife Rehabilitation and Conservation in India, birth to one month of age are neonates; 2-12 months are infants; 12-36 months (till weaning) are calves; and >3 years are juveniles (Bhaskar Choudhury).
Surprisingly little has been written about the developmental stages of Asian elephant calves. Elephant calves are precocial--capable of walking and suckling soon after birth (Sukumar, 2003). Nair divides the first year of life into four periods: 0-3 months (total dependence on adults); 3-6 months (exploratory period with intense practicing); 6-9 months (partial independent feeding); and 9-12 months (independent feeding) (Nair, 1989). Trunk control, motor skills, and social and non-social behaviors develop over many months (Revathe et al., 2020).
The well-being of young elephants, particularly those under one year of age, is intricately tied to their need for social companionship. These calves form profound bonds with their human caregivers. It is best to assign a limited number of dedicated keepers to care for the orphan calf. While limiting the number of caregivers to one or two individuals may be ideal, the hours of work demanded of staff must also be considered as well as the potential for the calf to become too attached and experience separation anxiety if separated from these individuals or the assigned care-givers are no longer available (Emanuelson 2006).
Caregivers occupy a central role in the lives of these little elephants, often providing care on a one-on-one or paired basis, recognizing the unique traits of each calf. The feeding behaviors of elephant calves can vary widely, with some individuals savoring each mouthful of milk slowly, while others eagerly and rapidly finish their bottle. Understanding these individual preferences is vital for fulfilling their nutritional needs. Additionally, during periods of illness or discomfort, elephant calves may adopt a more gradual nursing pace, occasionally taking extended breaks between sips. External factors such as cold weather or unfamiliar surroundings can also exert an influence on their feeding behavior. A lack of awareness regarding the specific needs of a slow-feeding calf poses the risk of underfeeding, potentially resulting in compromised growth and health.
Figure 7.1 Orphan calf bonding with his caregiver in Vietnam. Photo credit: Susan Mikota
Allo-Parenting
​
Allo-parenting is any form of parental care provided by an elephant to a calf that is not its own offspring. Female calves may exhibit allo-parenting behavior even when they are only 4-5 years old. Allo-parents play a crucial role in the well-being and development of the young elephants. The presence of an allo-mother has a positive influence on the emotional well-being of the orphan calf. This bond extends to activities like accompanying her to water sources and grasslands. The young calf observes and imitates the mother figure, which, in turn, accelerates its transition to consuming solid food compared to solitary calves. This nurturing relationship is demonstrated through behaviors such as suckling the ear pinna or teat of the allo-parent. Allo-parenting fosters emotional well-being. See Figures 7.2 and 7.3.
Monitoring Growth
Measurements such as weight, height, and body length are used to monitor growth. Growth trends can be tracked by taking measurements at regular intervals, at least monthly. An elephant calf's growth is influenced by numerous factors; by regular tracking deviations can be noted and addressed. Variations in growth patterns may indicate underlying health issues or inadequacies in the diet.
New born elephants typically have a shoulder height of 90 cm (3 feet). Table 2.3 lists weights, heights, and the presence of teeth for newborn elephants up to 25 weeks.
Regular weighing is the optimal method for monitoring growth but requires an appropriate scale which can be expensive. See Figure 7.4. The orphan calf should gain 0.5 kg–1.4 kg (1–3 lbs) per day, averaging 0.9 kg (2 lbs) of weight gain per day during the first year of life (Emanuelson, 2006). Weigh daily if possible or at least once a week.
​
Photographic documentation and body condition scoring can serve as a visual growth record if a scale is not available. Body condition scoring is based on a visual assessment of ribs, scapular bone, pelvic bone, and back bone.
![Figure 7.2 Mother cow with her calf and an orphan she is nuturing.jpg](https://static.wixstatic.com/media/ec3724_d12ee32f8c034cd6a90bc1a8288d6ff1~mv2.jpg/v1/crop/x_0,y_0,w_4202,h_2848/fill/w_418,h_283,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_2%20Mother%20cow%20with%20her%20calf%20and%20an%20orphan%20she%20is%20nuturing.jpg)
Figure 7.2 Mother cow with her calf and an orphan she is nurturing.
![Figure 7.3 Calf sucking the ear of the allo-mother.jpg](https://static.wixstatic.com/media/ec3724_4c1c13738381481da33f4e1882a76698~mv2.jpg/v1/crop/x_33,y_0,w_4207,h_2848/fill/w_418,h_283,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_3%20Calf%20sucking%20the%20ear%20of%20the%20allo-mother.jpg)
Figure 7.3 Calf sucking the ear of the allo-mother.
![Figure 2.8 Weighing using Digital scale.jpg](https://static.wixstatic.com/media/ec3724_ccdecd7d69a340219ac381d13e88fe2f~mv2.jpg/v1/crop/x_0,y_9,w_922,h_869/fill/w_418,h_394,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%202_8%20Weighing%20using%20Digital%20scale.jpg)
Figure 7.4 Weighing a young elephant using a digital scale. Photo credit: Susan Mikota
A body condition scoring system for elephant calves was developed by the author (Dr. Vijitha Perera) at the Elephant Transit Home based on previous systems developed for adult elephants (Wijeyamohan et al, 2015; Morfeld et al., 2016; Schiffmann et al., 2017).
​
Using this method, Body Condition Scores (BCS) of 1-3 can be considered indicative of poor nutrition, while scores of 4-6 suggest moderate and ideal nutritional conditions. BCS values of 7-8 are indicative of an excessive level of nutrition. See Figure 7.5. A photo gallery is provided below with examples of each body score.
Figure 7.5 Body condition scoring system for Asian elephant calves.
![Figure 7.5 BCS for calves.jpg](https://static.wixstatic.com/media/ec3724_8c8d33709b8b4b0286c7cf24e8543d88~mv2.jpg/v1/crop/x_210,y_0,w_1068,h_717/fill/w_721,h_484,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_5%20BCS%20for%20calves.jpg)
![Body Condition Score #1](https://static.wixstatic.com/media/ec3724_0bd182b9fd8146e0bc4b0407f6a573ce~mv2.jpg/v1/fill/w_980,h_760,al_c,q_85,usm_0.66_1.00_0.01,enc_auto/ec3724_0bd182b9fd8146e0bc4b0407f6a573ce~mv2.jpg)
![Body Condition Score #2](https://static.wixstatic.com/media/ec3724_c7d4fa6e21884dd79c57b5c44f5f160b~mv2.jpg/v1/fill/w_980,h_730,al_c,q_85,usm_0.66_1.00_0.01,enc_auto/ec3724_c7d4fa6e21884dd79c57b5c44f5f160b~mv2.jpg)
![Body Condition Score #8](https://static.wixstatic.com/media/ec3724_b41653f35a1f469ca76741dc2467a7ad~mv2.jpg/v1/fill/w_980,h_653,al_c,q_85,usm_0.66_1.00_0.01,enc_auto/ec3724_b41653f35a1f469ca76741dc2467a7ad~mv2.jpg)
![Body Condition Score #1](https://static.wixstatic.com/media/ec3724_0bd182b9fd8146e0bc4b0407f6a573ce~mv2.jpg/v1/fill/w_980,h_760,al_c,q_85,usm_0.66_1.00_0.01,enc_auto/ec3724_0bd182b9fd8146e0bc4b0407f6a573ce~mv2.jpg)
Body Condition Score
#1 (thinnest) to #8 (fattest)
Click on image below to view slideshow
Weaning
​
Calves in the wild depend on milk for the first two years of life. Weaning in the wild naturally occurs at three or four years of age when the mother is typically ready to give birth again.
​
For mother-reared calves, the weaning age depends on both the mother and the calf's behavior. Some calves form strong attachments to their mothers and have a strong desire for milk. Some mothers are more tolerant of their infants' demanding behaviors than others. In exceptional cases, young elephant calves may continue to suckle from their mother even after she has given birth to the next calf. However, in most cases, calves naturally stop suckling at approximately 3-4 years of age.
Weaning an orphan that had been bottle-fed should be a gradual process. Weaning can be started at 12-14 months of age by gradually decreasing the amount of milk and increasing the amount of solid foods offered. Complete weaning before 2 years of age is not advisable and it is best to continue some bottle feeding until the calf is at least 3 years old.
Orphaned elephants are typically willing to consume milk even when they are much older (8 years of age). In facilities like the Elephant Transit Home in Sri Lanka, calves are fed milk until they are ready to be released back into the wild. This means that some calves may receive milk until they are juveniles. During the feeding process, the maximum amount of milk is provided to the younger calves. However, the feeding ration does not change as they get older. As a result, growing animals must meet their nutritional requirements through solid food by foraging.
Coprophagy
Coprophagy is the consumption of feces. Mother-reared calves will normally ingest feces of adult elephants. This behavior is believed to contribute to the development of a healthy gut microbiome. This behavior can vary, ranging from simply sniffing the droppings to actually eating pieces of fecal matter and playing with feces. Sometimes, the calves may taste the softer feces, while at other times, they may ingest fecal boluses. Orphan calves should be offered feces from healthy adult elephants starting at 3-4 months of age. In situations where adult elephants are not readily available, calves can even be fed adult fecal matter by incorporating it into their milk.
![Figure 7.6 Coprophagy.jpg](https://static.wixstatic.com/media/ec3724_9c40ddec95644e20b31c8a57dbccb039~mv2.jpg/v1/fill/w_416,h_312,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_6%20Coprophagy.jpg)
Figure 7.6 Coprophagy in a young calf. Photo credit: Susan Mikota
Behavioral Development
​
During the first three months of life, the calf practices behaviors needed for feeding. Manipulation skills increase between three and six months of age and by six to nine months the calf is able to pull, collect grass, and place it in the mouth. By this time they have also learned to efficiently use their front legs to dislodge vegetation and to remove soil from grass by shaking against their legs as adults do (Nair 1989). Table 7.1 lists typical calf behaviors and the ages they are noted.
​
Webber has written an in-depth thesis comparing the behavioral development of elephant calves in captivity and in the wild (Webber, 2017).
​
​
​
![Table 7.1 Calf behaviors and the age observed.jpg](https://static.wixstatic.com/media/ec3724_32edf510ccd74668919bfc134328d920~mv2.jpg/v1/fill/w_968,h_744,al_c,q_85,usm_0.66_1.00_0.01,enc_auto/Table%207_1%20Calf%20behaviors%20and%20the%20age%20observed.jpg)
Exercise and Play
​
Exercise is important for the growing calf. Walking with the calf is a simple activity that can be enriching and can help strengthen the bond between the calf and caregiver while also providing exercise to help the calf develop muscle strength and motor skills. See Figure 7.7.
​
Play behavior reflects positive emotions and is considered an indicator of well-being. Work done with wild African elephants has shown that high play rates early in development correlates with long-term survival while lesser amounts of play are associated with slower growth and higher mortality (Lee et al., 2013; Lee and Moss, 2014).
​
Play helps the calf to learn about its environment, hone motor skills, solve problems and develop social skills. Play should be encouraged. In one study, captive Asian elephant calves spent about 22% of their waking time playing compared to 15% spent by wild calves (Webber 2020). Resting is also important for young calves; sand provides a comfortable substrate. See Figure 7.8.
​
Play behaviors may be social or non-social. In non-social lone play, calves engage in behaviors like running, spinning, rocking, and kicking. They may vocalize. This is typical of calves under six months of age. Make sure that the young calf has enough room to express these behaviors.
In non-social object play, calves interact with objects that they might roll or throw using their trunk, mouth or feet. Objects may include things in the environment like mud, water, or vegetation (Webber 2020). Provide items like logs to climb on and over, large balls to roll or kick, hanging tires, or hanging logs to butt. See figure below. Make sure that the calf cannot become tangled in ropes or chains used to suspend play objects.
Social play may involve gentle or more vigorous contact with other calves. During gentle contact calves may intertwine trunks, roll or lean against each other or wrestle. This is typical of infants and young juveniles whereas older juveniles and adolescents are more likely to engage in more aggressive pushing, shoving, and sparring (Webber and Lee, 2020). See Figure 7.9.
Caregivers are cautioned to avoid participating in games of chase or otherwise engaging in rough forms of play with calves. Elephants calves already weigh 200 pounds at birth and may weigh hundreds of pounds more in just a few months. Rough play with humans reinforces an unacceptable and potentially dangerous behavior.
![Figure 7.7 Mahouts walking w calves.jpg](https://static.wixstatic.com/media/ec3724_126e5d4c59e44d63bd70a8bfdc81d962~mv2.jpg/v1/crop/x_358,y_0,w_3914,h_2397/fill/w_416,h_255,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_8%20Mahouts%20walking%20w%20calves.jpg)
Figure 7.7 Mahouts walking with calves. Photo credit: Vijitha Perera
![Figure 7.8 Resting is important for young calves. Sand provides a comfortable substrate.jp](https://static.wixstatic.com/media/ec3724_70a4d5cac89a4b698d2d635415605fb8~mv2.jpg/v1/fill/w_408,h_271,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_7%20Resting%20is%20important%20for%20young%20calves_%20Sand%20provides%20a%20comfortable%20substrate_jp.jpg)
Figure 7.8 Resting is important for young calves. Sand provides a comfortable substrate. Photo credit: Willem Schaftenaar
![Figure 7.9 Young calves social play.jpg](https://static.wixstatic.com/media/ec3724_65948a1d1b154839b17c9af6fb6dbe30~mv2.jpg/v1/crop/x_0,y_34,w_1398,h_1174/fill/w_411,h_345,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_9%20Young%20calves%20social%20play.jpg)
Figure 7.9 Calves engaging in gentle social play. Photo credit: Susan Mikota
Enrichment
Enrichment is the process of modifying the environment or providing objects that encourage the calf to explore, practice normal behaviors, enhance social opportunities, solve problems, and experience novelty. Enrichment provides choices that enable the calf to have a sense of control. Enrichment promotes well-being and helps to prevent stereotypic behavior. Stereotypic behavior is repetitive behavior like head bobbing or rocking back and forth and generally reflects stress or boredom.
Enrichment can be provided by changing elements in the environmental, offering novel food items, providing special scents, or making “toys” that the calf can interact with. Things that move, can be manipulated, torn up, or make noise are good. Refer to Table 7.2 for ideas. Figures 7.10 – 7.17 are examples of enrichment.
![Table 7.2 Enrichment ideas.jpg](https://static.wixstatic.com/media/ec3724_a816c01035c04b3aa0ba4c10e627f409~mv2.jpg/v1/fill/w_612,h_623,al_c,q_85,usm_0.66_1.00_0.01,enc_auto/Table%207_2%20Enrichment%20ideas.jpg)
![Figure 7.10 Burlap feeders.jpg](https://static.wixstatic.com/media/ec3724_db76f19182d842829c000a6c685f990d~mv2.jpg/v1/fill/w_444,h_333,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_10%20Burlap%20feeders.jpg)
Figure 7.10 Burlap feeders
![Figure 7.12 Log with holes cut to hide food.jpg](https://static.wixstatic.com/media/ec3724_a9036ccaa1244706b4fe428f7a75fabb~mv2.jpg/v1/fill/w_444,h_333,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_12%20Log%20with%20holes%20cut%20to%20hide%20food.jpg)
Figure 7.12 Log with holes cut to hide food
![Figure 7.14 Tire feeder.jpg](https://static.wixstatic.com/media/ec3724_005e9f1cc0d744f496961988f382874d~mv2.jpg/v1/crop/x_0,y_0,w_890,h_668/fill/w_444,h_333,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_14%20Tire%20feeder.jpg)
Figure 7.14 Tire feeder
![Figure 7.16 Browse puzzle.jpg](https://static.wixstatic.com/media/ec3724_ebb63a2cf7f14030a601e6b538bf890b~mv2.jpg/v1/crop/x_0,y_109,w_1177,h_872/fill/w_444,h_329,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_16%20Browse%20puzzle.jpg)
Figure 7.16 Browse puzzle
![Figure 7.11. Hanging tires and log.jpg](https://static.wixstatic.com/media/ec3724_1512e38ea23e4a7ba67a1942046181fe~mv2.jpg/v1/fill/w_444,h_333,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_11_%20Hanging%20tires%20and%20log.jpg)
Figure 7.11 Hanging tires and log
![Figure 7.13 Leaf Wraps.jpg](https://static.wixstatic.com/media/ec3724_fb2c11d996de4cf5ba8a5a35ae560cb0~mv2.jpg/v1/crop/x_0,y_0,w_3056,h_2264/fill/w_444,h_329,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_13%20Leaf%20Wraps.jpg)
Figure 7.13 Leaf wraps
![Figure 7.15 Logs and browse.jpg](https://static.wixstatic.com/media/ec3724_c8c371853b0044efae66ea91ccafb6ce~mv2.jpg/v1/crop/x_0,y_14,w_3056,h_2264/fill/w_444,h_329,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_15%20Logs%20and%20browse.jpg)
Figure 7.15 Logs and browse
![Figure 17.17 Hay net.jpg](https://static.wixstatic.com/media/ec3724_ee783720192b4da5848f0fde004f09f4~mv2.jpg/v1/crop/x_0,y_160,w_540,h_400/fill/w_444,h_329,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%2017_17%20Hay%20net.jpg)
Figure 7.17 Hay net
Safety Warning!
​
Inspect enrichment items, especially hanging objects daily for safety. Check that the devices used to secure hanging objects (quick-release, clevis pins, anchor shackles) are tight. Swivels are best to attach hanging enrichment objects. Avoid using loops of rope or chain that the calf may become entangled in. Do not offer items that are small enough for the calf to swallow (e.g. tennis balls).
Socialization
​
The orphan Asian elephant calf is most ideally maintained among a group of elephants of different ages to facilitate normal social development. If a hand-raised calf is not able to spend time with other elephants, normal behaviors may be slow to develop. In this situation, the care-givers need to encourage behaviors like dusting, eating solid foods, mud wallowing, swimming, and play.
Contact with other elephants should be encouraged, especially for calves between the age of 6-12 months when maternal antibodies against EEHV are declining. This time window is probably the best period for the young calf to be exposed to this virus in order to build up solid life-long immunity against EEHV.
​
Managing Orphan Elephant Calf Groups
When managing a group of orphaned elephant calves emphasis should be placed on fostering group cohesion and encouraging social interactions. Keeping the calves together in a group setting not only prevents them from feeling isolated but also mirrors the natural dynamics of a herd. This group structure offers significant advantages, particularly in terms of social learning and experience sharing. See Figures 7.18 and 7.19.
![Figure 7.18 Raising calves of mixed age group.jpg](https://static.wixstatic.com/media/ec3724_3f5d88abd27943a1a8a2b196e26fd027~mv2.jpg/v1/fill/w_440,h_296,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_19%20Raising%20calves%20of%20mixed%20age%20group.jpg)
Figure 7.18 Raising calves of mixed age group
![Figure 7.19 Young elephants feeding.jpg](https://static.wixstatic.com/media/ec3724_0b1707c718d44a9ca862a1a1fc343437~mv2.jpg/v1/fill/w_402,h_296,al_c,q_80,usm_0.66_1.00_0.01,enc_auto/Figure%207_20%20Young%20elephants%20feeding.jpg)
Figure 7.19 Young elephants feeding. (Note: aggression by some individuals towards younger ones needs to be carefully monitored)
Living in a group setting provides ample opportunities for the calves to acquire essential natural skills. Interactions within the group enable them to learn from each other, enhancing their understanding of behaviors, communication, and survival tactics. However, it's important to exercise caution, especially regarding social hierarchical behavior. In some cases, young calves may exhibit rudeness towards subordinate members, particularly among males. Therefore, careful observation and intervention may be necessary to ensure their interactions remain positive and non-harmful.
Interestingly, distinct social dynamics emerge between male and female calves. While males may display hierarchical behaviors, females often exhibit more collaborative behavior. Adult female calves often assume the role of alloparents, acting as surrogate caregivers for the younger calves. This altruistic behavior contributes to the psychological well-being and confidence of the newcomers, as they receive care and support from experienced and caring individuals within the group.
By maintaining a group structure and paying attention to the complexities of social interactions, the facility creates an environment that not only supports the physical development of the orphaned elephant calves but also nurtures their social and psychological well-being. This comprehensive approach prepares them for a successful transition back to their natural habitat while instilling them with the skills and confidence necessary to thrive within a herd.
Training
For calves that will remain in captivity, positive reinforcement training can be very enriching and can be started at a very young age. Training is discussed in Chapter 10 (Training for Veterinary Procedures).
​
​
​
​
Literature Cited
​
Emanuelson, K., 2006. Neonatal care and hand rearing. In: Fowler, M.A., Mikota, S. (Eds.), Elephant Biology, Medicine, and Surgery. Blackwell, 233-241.
​
Fernando, P., Vijayakrishnan, S., Ranjeewa Ashoka, D.G., Pastorini, J., 2020. Size-age class scale for Asian elephants. Gajah 55, 30-39.
​
Lee, P.C., Bussiere, L.F., Webber, C.E., Poole, J.H., Moss, C.J., 2013. Enduring consequences of early experiences: 40 year effects on survival and success among African elephants (Loxodonta africana). Biol Lett 9, 20130011.
​
Lee, P.C., Moss, C.J., 2014. African Elephant Play, Competence and Social Complexity. Animal Behavior and Cognition 2.
Morfeld, K.A., Meehan, C.L., Hogan, J.N., Brown, J.L., 2016. Assessment of body condition in African (Loxodonta africana) and Asian (Elephas maximus) elephants in North American zoos and management practices associated with high body condition scores. PLoS ONE 11.
​
Nair, P.V., 1989. Development of nonsocial behaviour in the Asiatic elephant. Ethology 82, 46-60.
Petraccione, J., Root0Gutteridge, H., Cusano, D.A., Parkes, S.E., 2017. Exploring the early social affiliations and behaviour of a captive Asian elephant (Elephas maximus) calf. Journal of Zoo and Aquarium Research 5, 131-136.
​
Revathe, T., Anvitha, S., Vidya, T.N.C., 2020. Development of motor control and behaviour in Asian elephants in the Kabini elephant population, southern India. Int J Dev Biol 64, 367-382.
​
Schiffmann, C., Clauss, M., Hoby, S., Hatt, J.M., 2017. Visual body condition scoring in zoo animals–composite, algorithm and overview approaches. Journal of Zoo and Aquarium Research 5, 1-10.
​
Sharma, R., Krishnamurthy, K.V., 1984. Behavior of a neonate elephant (Elephas maximus). Appl. Anim. Beh. Sci 13, 157-161.
Sukumar, R., 2003. The Living Elephants. Oxford University Press.
​
Webber, C.E., 2017. A Comparison of Behavioural Development of Elephant Calves in Captivity and in the Wild: Implications for Welfare. Natural Sciences. University of Sterling, 338.
​
Webber, C.E., Lee, P.C., 2020. Play in Elephants: Wellbeing, Welfare or Distraction? Animals (Basel) 10.
​
Wijeyamohan, S., Treiber, K., Schmitt, D., Santiapillai, C., 2015. A Visual System for Scoring Body Condition of Asian Elephants (Elephas maximus). Zoo Biology 34, 53-59.