Changes in group composition are not exclusive to zoos and conservation breeding centers. The recent increase in poaching of African rhino species has accelerated the arrival of orphan calves at rehabilitation centers. Introducing new members into an existing group is often stressful for many mammal species. However, when young animals are involved, such responses may be reduced or absent. The goal of the present study was to evaluate the effect of introducing orphan calves on the stress responses of young orphan rhino from existing groups. The behavior and fecal glucocorticoid metabolite (fGCM) concentrations of eight orphan southern white rhinoceros (Ceratotherium simum simum) were assessed 1 month before and after the introduction of a new calf. From the 10 variables measured, only the response to humans and submissive behaviors showed significant changes. Stereotypies were not observed during the course of the study, and adrenocortical activity, monitored by means of fGCM concentrations, did not increase after the introductions, showing values within the range observed in free-ranging white rhino. However, strong individual differences were evident in most variables. Our results suggest that the introduction of white rhino calves into an existing group of young rhinos caused minimal stress in existing group members. Although these findings should be treated with caution when generalizing to other captive populations due to the small and heterogeneous sample, our findings may have management implications for rhino orphanages as well as zoos and breeding centers where non-breeding pairs are frequently maintained.

中文翻译：

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圈养的白犀牛青少年对引入新小牛的行为和肾上腺皮质反应

群体组成的变化并不仅仅局限于动物园和保护繁殖中心。最近非洲犀牛物种偷猎的增加加快了孤牛犊到达康复中心的速度。对于许多哺乳动物来说，将新成员引入现有的团队通常会感到压力。但是，当涉及幼小动物时，这种反应可能会减少或消失。本研究的目的是评估引入孤牛犊对来自现有群体的幼小孤犀牛的应激反应的影响。八个孤儿南部白犀牛的行为和粪便糖皮质激素代谢产物（FGCM）浓度（Ceratotherium simum simum）在引入新小牛前后1个月进行评估。从所测量的10个变量中，仅对人的反应和顺从行为显示出显着变化。在研究过程中没有观察到刻板印象，并且通过fGCM浓度监测的肾上腺皮质活动在引入后没有增加，显示出在自由放养的白犀牛中观察到的值。但是，在大多数变量中，很明显存在明显的个体差异。我们的结果表明，将白犀牛犊引入现有的幼犀牛群中，可以使现有群成员的压力最小。尽管由于样本量小且种类繁多，在推广到其他圈养种群时应谨慎对待这些发现，