Glucocorticoids (e.g. cortisol) are associated with variation in social behavior, and previous studies have linked baseline as well as challenge-induced glucocorticoid concentrations to dominance status. It is known that cortisol response to an acute challenge is repeatable and correlates to social behavior in males of many mammal species. However, it is unclear whether these patterns are also consistent for females. The aim of this study was to investigate whether baseline and response cortisol concentrations are repeatable in female guinea pigs (Cavia aperea f. porcellus) and whether dominance rank is stable and correlated to baseline cortisol concentration and/or cortisol responsiveness. Our results show that cortisol responsiveness (after 1 h: R = 0.635, 95% CI = 0.229, 0.927; after 2 h: R = 0.764, 95% CI = 0.433, 0.951) and dominance rank (R = 0.709, 95% CI = 0.316, 0.935) of females were significantly repeatable after six weeks but not correlated. Baseline cortisol was not repeatable (R = 0, 95% CI = 0, 0.690) and also did not correlate to dominance rank. Furthermore, the difference in repeatability estimates of baseline and response values was due to high within-individual variance of baseline cortisol concentration; the amount of between-individual variance was similar for baseline cortisol and the two measures of cortisol responsiveness. Females occupying different dominance ranks did not have long-term differences in cortisol concentrations, and cortisol responsiveness does not seem to be significantly involved in the maintenance of dominance rank. Overall, this study reveals the remarkable stability of cortisol responsiveness and dominance rank in a female rodent, and it remains an open question whether the magnitude of cortisol responsiveness is adaptive in social contexts for females.

中文翻译：

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雌性豚鼠内分泌特征和优势等级的重复性

糖皮质激素（例如皮质醇）与社会行为的变化有关，以前的研究已经将基线以及挑战诱导的糖皮质激素浓度与优势状态联系起来。众所周知，皮质醇对急性挑战的反应是可重复的，并且与许多哺乳动物物种的雄性社会行为相关。然而，尚不清楚这些模式是否也适用于女性。本研究的目的是调查雌性豚鼠 (Cavia aperea f. porcellus) 的基线和反应皮质醇浓度是否可重复，以及优势等级是否稳定并与基线皮质醇浓度和/或皮质醇反应性相关。我们的结果显示皮质醇反应性（1 小时后：R = 0.635, 95% CI = 0.229, 0.927；2 小时后：R = 0.764, 95% CI = 0.433, 0. 951) 和优势等级 (R = 0.709, 95% CI = 0.316, 0.935) 在六周后显着可重复，但不相关。基线皮质醇不可重复（R = 0, 95% CI = 0, 0.690），也与优势等级无关。此外，基线和响应值的可重复性估计的差异是由于基线皮质醇浓度的高个体内差异造成的。基线皮质醇和皮质醇反应性的两种测量方法的个体间差异量相似。占据不同优势等级的女性在皮质醇浓度方面没有长期差异，皮质醇反应性似乎与优势等级的维持​​没有显着相关。全面的，