Effect of Tourist Activities on Fecal and Salivary Glucocorticoids and Immunoglobulin A in Female Captive Asian Elephants in Thailand

Abstract

Asian elephants have been an important part of wildlife ecotourism in Thailand for over two decades. Elephants in tourist camps are exposed to a variety of management styles and daily activities that can potentially affect health and welfare. This study investigated relationships between a novel welfare biomarker, immunoglobulin A (IgA), and daily camp activities, and compared results to glucocorticoid (GC) measures. Often no-riding camps are portrayed as providing better welfare than camps that offer riding. Therefore, we predicted that elephants at no-riding camps would have lower GC and higher IgA concentrations, and a low GC/IgA ratio. Forty-four female elephants from six elephant camps were divided into three groups based on riding activities: saddle-riding, bareback-riding, and no-riding. Fecal and salivary samples were collected monthly for 1 year along with evaluations of body condition, foot health, and wounding. Camp environment and management varied among camps, although the major difference was in riding activities. Concentrations of GCs and IgA varied among the working groups, but not always consistently between sample matrices. Overall fecal glucocorticoid metabolite concentrations were lowest in the saddle-riding group. Only in one bareback-riding camp did the elephants exhibit a potentially positive welfare response with a low GC/IgA ratio over time. Other results varied between the two biomarkers, with considerable variability across camps, suggesting there is more to good welfare than whether elephants participate in riding or not. Several other human-induced stressors, like chaining, ankus use, and limited social opportunities are likely to be impacting well-being and should be considered to ensure management practices meet physical and psychological welfare needs.

A Longitudinal Study of Hematology and Stress Biomarker Profiles in Young Asian Elephants (Elephas Maximus) in Relation to Elephant Endotheliotropic Herpesvirus (EEHV) in Thailand

“…Saliva and fecal samples were collected twice a month during the 2nd and 4th week between 10.00–12.00 h, to avoid variation in circadian rhythms of cortisol [ 33 , 43 ]. Saliva was collected using a Salivette ® kit (Sarstedt, AG&Co, Numbrecht, Germany) and harvested by centrifuging at 1500× g for 2 min at 15 °C [ 42 ]. Fecal balls were mixed and approximately 20 g was collected into two separate zip-lock bags.…”

“…Fecal balls were mixed and approximately 20 g was collected into two separate zip-lock bags. All samples were transported in a 2–8 °C container box [ 42 ] to the Faculty of Veterinary Medicine, Chiang Mai University. All samples were stored at −20 °C until analysis [ 42 , 44 , 45 ].…”

“…All samples were transported in a 2–8 °C container box [ 42 ] to the Faculty of Veterinary Medicine, Chiang Mai University. All samples were stored at −20 °C until analysis [ 42 , 44 , 45 ]. Fecal samples were extracted as described previously for GCs [ 34 , 42 ] and IgA [ 42 , 46 ].…”

“…All samples were stored at −20 °C until analysis [ 42 , 44 , 45 ]. Fecal samples were extracted as described previously for GCs [ 34 , 42 ] and IgA [ 42 , 46 ].…”

“…IgA is the first line of immune defense at the mucosal surfaces of the gastrointestinal, respiratory, and genitourinary tracts, where more than 95% of infections are initiated [ 38 ]. In animals, restraint and isolation have been associated with lower IgA [ 39 , 40 ], whereas higher concentrations were indicative of a positive welfare state [ 36 , 41 , 42 ].…”