Free ranging animals are exposed to environmental, demographic, and ecological challenges over time, which can affect their health and fitness. Non-invasive biomarkers can provide insight into how animals cope with these challenges and assess the effectiveness of conservation management strategies. We evaluated how free ranging ponies (Equus ferus caballus) on the Carneddau Mountain range, North Wales respond to 2 stimuli: an acute stressor of an annual roundup event in November 2014, and spatial and temporal variation in ecological factors in 2018. We evaluated fecal glucocorticoid metabolites using 2 enzyme immunoassays (EIAs): an 11-oxoetiocholanolone EIA (measuring 11,17-dioxoandrostanes [11,17-DOAs]) and a corticosterone EIA. The former assay has been validated in equids, whereas there is limited evidence for the suitability of the latter. We used an additional parent testosterone EIA to measure fecal androgen metabolites in response to the ecological challenges. Following the roundup, the metabolite concentrations measured by the 2 glucocorticoid EIAs were not correlated. The 11,17-DOAs were elevated from the second day following the roundup and then slowly returned to pre-round levels over the next 2 weeks. In contrast, the metabolites measured by the corticosterone assay showed no response to the roundup. For the ecological data, all 3 assays detected a positive correlation between metabolites and social group size in males but not in females. The metabolite concentrations measured by the testosterone and corticosterone assays were highly correlated and were temporally associated with the onset of the breeding season, whereas the 11,17-DOAs were not. The co-variance of metabolites measured by the corticosterone and testosterone assays, and the lack of an acute response in the corticosterone assay to the roundup, suggests that metabolites detected by the corticosterone assay were not primarily associated with increased glucocorticoid production. We recommend using well-validated fecal biomarker assays of hypothalamus-pituitary-adrenal axis activity to evaluate and compare the effect of different management interventions and environmental change. © 2021 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society.

中文翻译：

---

粪便糖皮质激素代谢物作为马科动物的生物标志物：检测选择很重要

随着时间的推移，自由放养的动物会面临环境、人口和生态方面的挑战，这会影响它们的健康和健康。非侵入性生物标志物可以深入了解动物如何应对这些挑战并评估保护管理策略的有效性。我们评估了自由放养的小马 ( Equus ferus caballus) 在北威尔士的 Carneddau 山脉，对 2 种刺激有反应：2014 年 11 月年度综合事件的急性压力源，以及 2018 年生态因素的时空变化。我们使用 2 种酶免疫分析法 (EIA) 评估了粪便糖皮质激素代谢物：一个 11-oxoetiocholanolone EIA（测量 11,17-dioxoandrostanes [11,17-DOA]）和一个皮质酮 EIA。前一种测定已在马科动物中得到验证，而后者适用性的证据有限。我们使用额外的母体睾酮 EIA 来测量粪便雄激素代谢物以应对生态挑战。在综述之后，2 种糖皮质激素 EIA 测量的代谢物浓度不相关。11, 17-DOA 从综述后的第二天开始升高，然后在接下来的两周内缓慢恢复到轮前水平。相比之下，通过皮质酮测定测量的代谢物显示对综述没有反应。对于生态数据，所有 3 项测定都检测到雄性代谢物与社会群体规模之间存在正相关，但在雌性中则没有。通过睾酮和皮质酮测定测量的代谢物浓度高度相关，并且与繁殖季节的开始在时间上相关，而 11,17-DOA 则不然。通过皮质酮和睾酮测定测量的代谢物的协方差，以及皮质酮测定对综述缺乏急性反应，表明皮质酮测定检测到的代谢物与糖皮质激素产量增加无关。我们建议使用经过充分验证的下丘脑 - 垂体 - 肾上腺轴活动的粪便生物标志物测定来评估和比较不同管理干预和环境变化的效果。© 2021 作者。由 Wiley Periodicals LLC 代表野生动物协会出版的《野生动物管理杂志》。