Annual dynamics between serum cortisol concentration and fecal cortisol concentration in a female captive tiger

Abstract

Evaluating the stress that captivity imposes on an animal will enhance the welfare of animals in captivity. In tigers, it is not clear how similar the cortisol concentration in feces is to the cortisol concentration in serum. In this study, we examined the dynamics of cortisol concentration throughout the year, and the relationship between fecal cortisol concentration and serum cortisol concentration, in a female captive tiger. There was a significant positive correlation between cortisol levels in fecal and serum (r=0.60, P<0.01).

The fecal cortisol concentration was found to reflect the variation of the serum cortisol concentration. This suggests that the fecal cortisol concentration is useful for non-invasive stress assessment. In tigers, serum and fecal cortisol concentrations showed no seasonal variation, further suggesting that it is useful as an index for stress assessment throughout the year. In other subspecies, such as the Amur tiger and Sumatran tiger, fecal cortisol concentrations were also unaffected by seasonal fluctuations, again indicating that fecal cortisol concentrations can be used to assess stress throughout the year.