Campbell Kaitlyn M, Marolf Chelsi J, Buss Peter E, Morfeld Kari A
For Elephants, Inc., Omaha, NE 68134, USA.
School of Natural Resources, University of Nebraska, Lincoln, NE 68588, USA.
Animals (Basel). 2025 Jun 24;15(13):1863. doi: 10.3390/ani15131863.
Understanding hormone patterns in free-ranging African elephants can provide critical insights for the management of elephants in human care, particularly in addressing reproductive anomalies and the rising prevalence of obesity in zoo populations. This study is the first to establish baseline values for glucose, insulin, and leptin, and their potential relationships with reproductive and stress hormones. We measured the hormones in serum samples collected opportunistically in Kruger National Park between 2000 and 2016. Endocrine profiles were compared across age groups in both male and female elephants and between the wet and dry seasons. In females, progestogen and prolactin levels were highest in adults, and were not significantly correlated with the glucose-to-insulin (G/I) ratio or leptin. In males, testosterone levels were higher in adults, and the G/I ratio was a significant predictor of testosterone concentrations. Seasonal variations revealed that, in males, testosterone levels were higher, and cortisol concentrations were lower during the rainy season. In females, cortisol concentrations were negatively associated with progestogen levels during the dry season. These benchmarks offer zoos a reference point to assess whether current management approaches are effective, and how natural variation with the season may impact hormone levels.
了解野生非洲象的激素模式可为人工饲养大象的管理提供关键见解，特别是在解决生殖异常和动物园种群中肥胖率上升的问题上。本研究首次确定了葡萄糖、胰岛素和瘦素的基线值，以及它们与生殖和应激激素的潜在关系。我们测量了2000年至2016年期间在克鲁格国家公园机会性采集的血清样本中的激素。对雄性和雌性大象的不同年龄组以及雨季和旱季的内分泌特征进行了比较。在雌性大象中，孕激素和催乳素水平在成年大象中最高，且与葡萄糖与胰岛素（G/I）比值或瘦素无显著相关性。在雄性大象中，成年大象的睾酮水平较高，G/I比值是睾酮浓度的重要预测指标。季节性变化表明，在雄性大象中，雨季时睾酮水平较高，皮质醇浓度较低。在雌性大象中，旱季时皮质醇浓度与孕激素水平呈负相关。这些基准为动物园提供了一个参考点，以评估当前的管理方法是否有效，以及季节的自然变化可能如何影响激素水平。
