The European ground squirrel (Spermophilus citellus) is a rodent inhabiting the open grasslands of central and southeastern Europe. The species is endangered, and various conservation activities are being conducted to preserve and improve the populations’ status, especially during the recent years including translocations of individuals. The success of these measures has varied and is potentially strongly influenced by the chronic and acute stress associated with the translocation process itself. This stress load, however, has rarely been investigated in the framework of such conservation projects, neither in translocated nor in resident individuals. To fill this gap, we investigated glucocorticoid metabolite concentrations in translocated ground squirrels and compared these with concentrations in resident animals of a reinforced colony in southeastern Bulgaria. Between 2017 and 2019, we sampled a total of 252 individuals for faecal cortisol metabolite concentrations (FCM). The results showed that FCM decreased after the release in translocated individuals and that the time span after the translocation event was the key variable explaining the decrease. Surprisingly, the FCM levels were higher in the resident ground squirrels than in the translocated individuals throughout the active season and in the following spring. Furthermore, we found no effect of FCM concentrations on dispersal distances or body mass gain in translocated individuals.

中文翻译：

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在保护加固后，欧洲常驻地松鼠比易地松鼠表现出更高的压力水平

欧洲地松鼠 (Spermophilus citellus) 是一种啮齿动物，栖息在欧洲中部和东南部的开阔草原上。该物种濒临灭绝，正在开展各种保护活动以保护和改善种群状况，特别是近年来，包括个体易地。这些措施的成功程度各不相同，并且可能受到与易位过程本身相关的慢性和急性压力的强烈影响。然而，这种压力负荷很少在此类保护项目的框架内进行研究，无论是在易地还是居民个体中。为了填补这个空白，我们研究了易位地松鼠的糖皮质激素代谢物浓度，并将这些浓度与保加利亚东南部一个强化殖民地的常住动物的浓度进行了比较。2017 年至 2019 年期间，我们对 252 个人的粪便皮质醇代谢物浓度 (FCM) 进行了采样。结果表明，易位个体释放后FCM下降，易位事件发生后的时间跨度是解释下降的关键变量。令人惊讶的是，在整个活跃季节和接下来的春天，常驻地松鼠的 FCM 水平高于易地松鼠。此外，我们发现 FCM 浓度对易位个体的分散距离或体重增加没有影响。我们对 252 个人的粪便皮质醇代谢物浓度 (FCM) 进行了采样。结果表明，易位个体释放后FCM下降，易位事件发生后的时间跨度是解释下降的关键变量。令人惊讶的是，在整个活跃季节和接下来的春天，常驻地松鼠的 FCM 水平高于易地松鼠。此外，我们发现 FCM 浓度对易位个体的分散距离或体重增加没有影响。我们对 252 个人的粪便皮质醇代谢物浓度 (FCM) 进行了采样。结果表明，易位个体释放后FCM下降，易位事件发生后的时间跨度是解释下降的关键变量。令人惊讶的是，在整个活跃季节和接下来的春天，常驻地松鼠的 FCM 水平高于易地松鼠。此外，我们发现 FCM 浓度对易位个体的分散距离或体重增加没有影响。在整个活跃季节和接下来的春天，常驻地松鼠的 FCM 水平高于易地松鼠。此外，我们发现 FCM 浓度对易位个体的分散距离或体重增加没有影响。在整个活跃季节和接下来的春天，常驻地松鼠的 FCM 水平高于易地松鼠。此外，我们发现 FCM 浓度对易位个体的分散距离或体重增加没有影响。