Health Issues Associated with Captivity: Killing the Elephants Zoos Promised to Save from Extinction

by Devan Schowe in Animals in Captivity, Blog

While zoos claim that they work to improve captive elephant welfare and save elephant populations from extinction in the wild, more elephants die at zoos than are born in North America. Yes, you read that right. Since 2000, more captive elephant deaths have occurred than births; sadly, deaths have equaled or exceeded births in 20 out of the recorded 21 years in the United States (The Elephant Database, 2021).

Several factors shed light on the high mortality rate observed in captive elephants: high infant mortality rate, low birth rate, high stillborn birth rate, and high prevalence of potentially fatal diseases related to the virus EEHV, frequent exhibition of stereotypic behaviors, foot/musculoskeletal issues, and obesity. All of these health adversities occur more frequently in captivity than in the wild.

While zoos claim that they work to improve captive elephant welfare and save elephant populations from extinction in the wild, more elephants die at zoos than are born in North America.

Captive Elephants Experience Many Reproductive Issues

In North America, the infant mortality rate for captive elephants is a devastatingly high 35% (Hagan et al., 2020). These trends may result from captive females experiencing reproductive onset at too young an age – wild Asian and African elephants typically reach reproductive onset around 11-12 years, whereas captive females as young as four years may be mated in zoos (Clubb et al., 2008). Females also appear to experience shorter interbirth intervals in captivity compared to their wild counterparts, which may enhance the probability of infant mortality (Lee & Moss, 1986).

An unnaturally shorter interbirth interval may be explained by zoos forcibly impregnating individuals either through exposing immature, barely weaned females to breeding males, or through artificial insemination procedures. Additionally, the rate of stillbirths is higher in captivity than in wild populations. Between 2000-2020, 20 of 121 pregnancies (16.5%) among captive elephants in the U.S. and Canada resulted in stillbirths.

Captive Elephants Are at Greater Risk of Elephant Endotheliotropic Herpesvirus (EEHV)

The fertility and birthing complications are just the tip of the health issues iceberg endured by captive elephants. A leading cause of infant mortality among captive Asian elephants is due to hemorrhagic disease caused by Elephant Endotheliotropic Herpesvirus (EEHV): an infectious herpesvirus only found in elephants and one of the most fatal diseases in captive elephants worldwide (Long et al., 2016). EEHV was responsible for 65% of fatalities in Asian elephants between three months and 15 years of age in European and North American zoos from 1993-2013 (Zachariah et al., 2013). Research has indicated that EEHV continues to be responsible for around half of all juvenile fatalities in North American and European zoos (Howard & Schaftenaar, 2019; Jesus et al., 2021). Since 2010, at least nine deaths in U.S. and Canadian zoos were due to EEHV. While African elephants are also susceptible to their own EEHV’s, reported fatalities are fewer (Long et al., 2016).

Although EEHV occurs in wild populations, it is not associated with the high mortality rate seen in captive Asian elephants (Howard & Schaftenaar, 2019). Therefore, the increased juvenile mortality of captive elephants from EEHV is highly influenced by keeping and managing elephant populations in captivity; indeed, early weaning, birth events, and transfers in/out of the group or between facilities have all been linked to a higher disease risk in captive elephants (Sanchez et al., 2016; Perrin et al., 2021). Research has revealed that previous EEHV deaths within a zoo indicate a 3.8 times higher risk of future EEHV deaths (Perrin et al., 2021). Zoos with the most active breeding programs presented an exceptionally high overall offspring loss due to EEHV: up to 50% of the total. A study from 2022 highlighted that captive elephants were more likely to shed EEHV during times of “social stress,” which can be relatively frequent at zoos, as most zoos do not come close to mimicking natural elephant social structure.

Captive Elephants Exhibit Stereotypies

Stereotypic behaviors are often indicators of compromised welfare (Mason & Veasey, 2010). These behaviors include swaying, head-bobbing, pacing, and circling in captive elephants (Mason, 2006). Within the U.S., a study discovered that 85.4% of elephants performed stereotypic behavior during the day and 68.8% during the night (Greco et al., 2016). These behaviors are a consequence of long-term psychological damage, often continue throughout the animals’ lives, and remain present to a greater or lesser degree even if their captive circumstances improve.

Living in an impoverished, stressful captive environment results in physical damage to the brain. These changes have been documented in many species, including elephants (Jacobs, 2020). Captive elephants, particularly those who experience one or more traumatic events, including injury, capture, translocation, or maternal separation, frequently exhibit damaged social and emotional functioning consistent with symptoms found in human survivors of trauma (Bradshaw et al., 2005).

Living in an impoverished, stressful captive environment results in physical damage to the brain.

Captive Elephants Experience a High Rate of Foot and Musculoskeletal Disease

In the wild, an elephant’s feet are exposed to various substrates and terrains every day. Walking across different surfaces helps to keep their fat pads healthy. Substrates provided for elephants in captivity often lack this variation. Inactivity and standing on hard substrates (like concrete) cause Blackleg (bacterial inflammation with necrosis), foot rot, pathological lesions in the pads and nails, abscesses, overgrown cuticles, split nails, torsion, and ulcerations (Wendler et al., 2019; Saddiq et al., 2020). In North America, 67.4% of elephants from a sample of zoos had a foot abnormality (145 out of 215). Of those elephants with recorded abnormalities, nail abnormalities were present in 92.4%, fat pads abnormalities in 13.1%, and abnormalities in the interdigital space in 22.8% (Miller, 2016).

Musculoskeletal impairments are also a major health issue for captive elephants, including degenerative joint disease and low bone density. Captive elephants may suffer from abscesses, arthritis, hernia (Hernia perinealis), osteoarthritis, skin calluses (Tyloma olecrani), and swelling of the knee joints (Bursitis praepatellaris) (Kuntze, 1989), which are likely related to standing on hard substrates. The significantly colder annual temperatures experienced in North America compared to the warmer climates that African and Asian elephants evolved to inhabit further amplify these issues, as most zoos keep elephants in even smaller indoor enclosures for most of the colder months.

Captive Elephants Experience Obesity

Obesity is a major problem that impacts the overall sustainability of the captive population (Morfeld et al., 2016). Captive diets often contain large amounts of non-forage items, including pelleted food, fruit, and vegetables. In North American zoos, 74% of elephants (177 out of 240) were reported to have a body condition score above normal, with just 22% having a normal score (Morfeld et al., 2016). Obesity likely increases susceptibility to the foot and musculoskeletal issues outlined above.

The Big Picture for Captive Elephants

There is not just one variable causing the mental suffering and physical deterioration of elephants held in captivity. Clearly, elephants do not thrive in captivity; they struggle to barely survive, in enclosures several orders of magnitude smaller than their home range. The AZA recommends a minimum enclosure size of just 0.12 acres per elephant; less than twice the size of a double’s tennis court.

These minimum enclosure size requirements are dictated by the space available to the zoo industry, rather than the needs of the elephants confined within them. This flawed and frankly exploitative ideology reflects the same reasoning zoos use to “justify” the very presence and propagation of elephants in captivity; elephants are not kept to better their conservation status in the wild, nor are they kept in attempts to improve their individual welfare. They are kept to attract more visitors, in spite of the persistent health issues they face.

Clearly, elephants do not thrive in captivity; they struggle to barely survive, in enclosures several orders of magnitude smaller than their home range.

Please help us end the keeping of elephants in captivity. Read and share our newest report, Elephants in Zoos – A Legacy of Shame, watch our video detailing the plight of elephants in captivity, and consider adopting an elephant, to help us fight to better ensure the health and well-being of future elephants in the wild, where they belong.

Keep Wildlife in the Wild,

Devan


Complete List of Article Sources

The Elephant Database (2021) https://elephant.se/

Hagan, D., Paxton, S., & Andrews, J. (2020). Population Analysis & Breeding and Transfer Plan African Elephant (Loxodonta Africana) AZA Species Survival Plan® Yellow Program. Association of Zoos & Aquariums: Population Management Center, 2-46.

Clubb, R., Rowcliffe, M., Lee, P., Mar, K.U, Moss, C., & Mason, G.J. (2008). Compromised survivorship, fecundity and population persistence in zoo elephants. Science, 322 (5908), 1649 – 1649. DOI:10.1126/science.1164298

Lee, P.C. & Moss, C.J. (1986). Early maternal investment in male and female African elephant calves. Behavioral Ecology and Sociobiology, 18 (5), 353-361.

Long, S.Y., Latimer, E.M., & Hayward, G.S. (2016). Review of elephant endotheliotropic herpesviruses and acute hemorrhagic disease. ILAR journal, 56 (3), 283-296

Zachariah, A., Zong, J.C., Long, S.Y., Latimer, E.M., Heaggans, S.Y., Richman, L.K., & Hayward, G.S. (2013). Fatal herpesvirus hemorrhagic disease in wild and orphan Asian elephants in southern India. Journal of wildlife diseases, 49 (2), 381-393.

Howard L.L. & Schaftenaar W. (2019). Elephant endotheliotropic herpesviruses. In: Miller R.E., Lamberski N., and Calle P (eds.), Fowler’s zoo and wild animal medicine. Current therapy Vol. IX. St. Louis, Missouri: Elsevier Inc., 672-679.

Jesus, S.A., Doherr, M.G., & Hildebrandt, T.B. (2021). Elephant Endotheliotropic Herpesvirus Impact in the European Asian Elephant (Elephas maximus) Population: Are Hereditability and Zoo-Associated Factors Linked with Mortality? Animals, 11 (10), 2816.

Sanchez, C.R., Wagener, T., Nevitt, D., Latimer, E., & Brown, J. (2016). Correlation between serum and urinary cortisol levels and shedding of elephant endotheliotropic herpesvirus (EEHV) 1, 3, 4 and 5 in calves and adult Asian elephants (Elephas maximus) pre- and post-arrival of a new bull elephant. Proceedings of the Joint AAZV / EAZWV / IZW Conference, 43–44. Atlanta, Georgia.

Perrin et al., 2021 https://www.jzar.org/jzar/article/view/553

Mason G.J. & Veasey J.S. (2010). How should the psychological wellbeing of zoo elephants be objectively investigated? Zoo Biology 29, 237–255

Mason, G. (2006). Stereotypic behavior: fundamentals and applications to animal welfare and beyond. In: Mason G, Rushen J, editors. Stereotypies in captive animals, 2nd edition. Wallingford, UK: CAB International, 325–356.

Jacobs, B. (2020). “The Neural Cruelty of Captivity: Keeping Large Mammals in Zoos and Aquariums Damages Their Brains.” The Science Times. [online]. https://www.sciencetimes.com/articles/27505/20200929/cruelty-zoosaquariums-damages-brains.htm.

Greco, B.J., Meehan, C.L., Hogan, J.N., Leighty, K.A., Mellen, J., Mason, G.J., & Mench, J.A. (2016). The days and nights of zoo elephants: using epidemiology to better understand stereotypic behavior of African elephants (Loxodonta africana) and Asian elephants (Elephas maximus) in North American zoos. PLoS One, 11 (7), p.e0144276.

Bradshaw, G.A., Schore, A.N., Brown, J.L., Poole, J.H., & Moss, C.J. (2005). Elephant breakdown. Nature, 433 (7028), 807-807

Wendler, P., Ertl, N., Flügger, M., Sós, E., Schiffmann, C., Clauss, M., & Hatt, J.M. (2019). Foot health of Asian elephants (Elephas maximus) in European zoos. Journal of Zoo and Wildlife Medicine, 50 (3), 513-527.

Saddiq, H. M. U., Ali, R. H., Amjad, M. T., Jaleel, S., Ali, S. M., Fatima, N., & Ullah, S. (2020). Post-mortem examination of a female elephant suspected of having Degenerative Joint Disease: A case report. Advances in Animal Veterinary Science, 8 (10), 1009-1012. http://dx.doi.org/10.17582/journal.aavs/2020/8.10.1009.1012.

Miller, M.A., Hogan, J.N., & Meehan, C.L. (2016). Housing and demographic risk factors impacting foot and musculoskeletal health in African elephants [Loxodonta africana] and Asian elephants [Elephas maximus] in North American zoos. PLoS One, 11 (7), e0155223.

Kuntze, A. (1989): Arbeitsbedingte Krankheitsbilder: Hernia perinealis, Bursitis praepatellaris und Tyloma olecrani bei Zirkuselefantinnen. Verh. Ber. Erkrg. Zootiere, 31, 185.

Morfeld, K.A., Meehan, C.L., Hogan, J.N., & Brown, J.L. (2016). Assessment of body condition in African (Loxodonta fricana) and Asian (Elephas maximus) elephants in North American zoos and management practices associated with high body condition scores. PloS one, 11 (7), e0155146


 

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