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.

Keywords: Asian elephant; feces; glucocorticoids; immunoglobulin A; saliva; tourism; welfare.

Figure 1

Mean (± SEM) monthly (a) fecal glucocorticoid metabolite (FGM) and (b) salivary cortisol concentrations in elephants involved in saddle-riding, bareback-riding, or no-riding. Box plots illustrate salivary cortisol and FGM measures for all elephants combined (N = 44). Whiskers represent median, quartiles, and the 25th/75th percentiles, error bars represent the 10th/90th percentiles, and open circles indicate outliers. Different superscripts indicate a significant difference at p < 0.05.

Figure 2

Mean (±SEM) of (a) fecal (µg/g) and (b) salivary (µg/mL) IgA concentrations in each elephant activity group. Box plot showed overall fecal and salivary IgA measures in combination with three elephant groups (N = 44). Whiskers represent median, quartiles, and the 25th/75th percentiles, error bars represent the 10th/90th percentiles, and open circles indicate outliers. Different superscripts indicate a significant difference at p < 0.05.