The tail-tale of stress: an exploratory analysis of cortisol levels in the tail-hair of captive Asian elephants

PeerJ

article

Sanjeeta Sharma Pokharel¹  Hiroki Yoneda³  Moe Yanagi¹  Raman Sukumar²  Kodzue Kinoshita¹ 

[1] Wildlife Research Center, Kyoto University;Centre for Ecological Sciences, Indian Institute of Science;Kyoto City Zoo;Institute for Advanced Study, Kyoto University

关键词: Hair cortisol;    Asian elephant;    Elephas maximus;    Tail hair;    Stress;    Stress physiology;   

DOI  :  10.7717/peerj.10445

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

BackgroundAssessment of physiological states by measuring biomarkers, such as cortisol, has significantly contributed to the monitoring of health, welfare and management of animals. Immunoreactive cortisol in hair (hC) has been used widely for deciphering ‘stressful’ past-events in various wild and captive animals. However, no such studies have been done in long-lived mammals.MethodsIn this first exploratory study in elephants, we assessed (i) tail-hair growth rate (TGR) and (ii) hC levels in tail-hair samples from six captive Asian elephants from two zoos in Japan for comparing hC levels with zoo-keepers’ records of distinct biological events over a c.0.5–2.0-year period. Tail-hair samples were cut into segments (based on monthly growth rate), pulverized or minced and a validated cortisol enzyme-immunoassay employed to measure hC levels.ResultsWhen the hC levels of all individuals were compared with the keepers’ records, a posteriori, most of the high hC levels were found to be associated with ‘stressful’ or distinct behavioural events such as pathological (anaemia, colic infection, skin infection, oral sores), psychosocial (reluctance in entering the enclosure, presence of a calf) and husbandry practice-related (contact trials/ space sharing) conditions, indicating that tail-hair indeed can be a potential ‘retrospective’ calendar of physiological health of an animal.ConclusionsOur observations open up the possibility of using the tail-hair as an alternative matrix to reconstruct the physiological history of elephants.

【 授权许可】

CC BY