Faecal Glucocorticoid Metabolites in the Dominant Males of a Captive Spotted Deer Population

Faecal steroid analysis was done from the faecal samples collected from dominant males of a captive deer population maintained at zoological garden, Thrissur, Kerala. Glucocorticoids-either cortisol or cortisterone –are released during stressful situations. It is established that a rapid short term release of glucocorticoids leads to mobilization of energy and behavioural changes and long term response may decrease fitness by suppressing reproductive performance. An attempt was made in this study to access if there is any significant correlation between these hormones in any stage of antler cycles of dominant males of captive spotted deer population. The dominant males were identified based on their body size, capacity to take vantage positions and dominance. The dominant males of winter season were named as Alpha I and Alpha II and the dominant males of summer season were named as velvet I & Velvet II. Faecal samples were collected once weekly and faecal glucocorticoid estimation was done by Radio Immuno Assay. The concentration of faecal glucocorticoids metabolites were maximum in velvet stage, followed by antler regrowth stage, casting stage and velvet shedding stage respectively. Faecal metabolite levels of glucocorticoids and testosterone were not correlated.