By Grace Kandrach, Supriya Jindal, PhD

Department of Biological, Geological, and Environmental Sciences

Cleveland State University

‍

Duke University

https://doi.org/10.55894/dv5.11

Abstract

Determining release readiness in rehabilitated wildlife is a critical step for post-release integration

and survival into the natural world. Traditional evaluations, such as physical examinations, and non-invasive

sampling methods (e.g., feather, saliva, and fecal testing) offer practical monitoring tools. However, they may

fail to detect underlying physiological stress, which can directly affect post-release survival rates in animals.

This review evaluates the use of neuroendocrine stress markers, specifically glucocorticoids, as predictors of

health and survival outcomes in rehabilitated wildlife. Evidence indicates that dysregulated glucocorticoid

levels negatively impact animal health (e.g., reproduction, foraging behavior, natural instincts, and post-release

survival success). However, its interpretation remains limited by species, sex, and age-specific variability,

and the lack of standardized baseline glucocorticoid reference ranges. When integrated with physical and

behavioral assessments, stress-hormone testing has the potential to improve and offer a comprehensive and

more accurate evaluation of an animal’s physiological state. Therefore, incorporating neuroendocrine stress

markers into release criteria can significantly improve predictions of post-release success.