An examination of salivary cortisol concentrations and behaviour in three African elephants Loxodonta africana at Zoo Atlanta

Abstract

Salivary cortisol assay is an effective method to quantify free cortisol levels, track diurnal patterns and measure acute hypothalamus-pituitary-adrenal activation in response to acute stressors. This study examined salivary cortisol and behaviour in three African elephants Loxodonta africana. Salivary cortisol was within normal ranges for this species, declined across the day and responded to a mild social stressor. The relationship between salivary cortisol and stereotypic swaying in two of the elephants was also examined. Swaying was significantly associated with decreased cortisol values in one of the two elephants, indicating this stereotypy may function to reduce arousal, but also emphasising the complicated relationship between physiology and behaviour. This is the first study to demonstrate that swaying reduces salivary cortisol concentrations in some elephants. The opportunities this finding presents for future research and the complex relationship between physiology and behaviour are discussed.