Fecal Glucocorticoid Monitoring - A Valuable Approach to Noninvasive Assessment of Cortisol and Stress in Wild Animals

Fecal glucocorticoid metabolites (FGMs) have emerged as a powerful, noninvasive tool for assessing adrenocortical activity in wildlife and domestic species. As biomarkers of physiological stress, FGMs offer a practical and ethical alternative to blood sampling, especially in studies involving free-ranging or sensitive animals. This chapter highlights how fecal analysis reflects systemic cortisol/corticosterone levels over time. Key advantages of this method include the avoidance of animal capture, high sampling repeatability, and the ability to monitor longitudinal stress patterns under natural conditions. Species-specific factors influencing glucocorticoid metabolism, sampling strategies, and methodological considerations for accurate data interpretation are also addressed. Given the growing applications of this technique in ecology, animal welfare, and conservation biology, the analysis of FGMs has become an essential component of endocrine monitoring in both field and captive settings.