Despite striking diversity in mammalian social behavior, studies of social organization have often dichotomized species by identifying them as either solitary or social (i.e., group living). This tendency has been particularly pronounced for subterranean rodents, the majority of which have long been assumed to be solitary. As a result, variation in social organization has likely been underestimated for these animals, particularly for species in which patterns of space use suggest limited or temporally dynamic opportunities for interactions among conspecifics. Here, we characterize patterns of space use in a population of tuco-tucos (Ctenomys sp.) from Anillaco, La Rioja Province, Argentina. Although these animals have been the subject of extensive research regarding circadian patterns of activity, spatial and social relationships among free-living individuals have not been documented. Analyses of radiotelemetry data from 17 individuals monitored during the breeding season (December 2015) revealed that partial overlap of individual home ranges was common, occurring between male–female as well as female–female pairs of animals. Spatial relationships, however, were dynamic, with both home range sizes and overlap changing on a daily basis. Although members of the study population did not meet the criteria typically used to identify group living in subterranean species, they were not completely solitary. Instead, the animals displayed an intermediate form of social organization characterized by persistent partial overlap of the areas occupied by different adults. These data add to the growing comparative picture of social variation in Ctenomys and suggest that further studies of these animals should contribute to improved understanding of the factors underlying differences in mammalian social systems.

中文翻译：

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孤独的地下啮齿动物的动态空间重叠：Anillaco tuco-tuco (Ctenomys sp.)

尽管哺乳动物的社会行为具有惊人的多样性，但对社会组织的研究通常通过将物种识别为孤独的或社会的（即群体生活）来将物种二分类。这种趋势在地下啮齿动物中尤为明显，其中大部分长期以来被认为是独居的。因此，这些动物的社会组织差异可能被低估了，特别是对于空间使用模式表明同种间相互作用的机会有限或暂时动态的物种。在这里，我们描述了来自阿根廷拉里奥哈省 Anillaco 的 tuco-tucos (Ctenomys sp.) 种群的空间使用模式。尽管这些动物已成为有关昼夜活动模式的广泛研究的主题，自由生活个体之间的空间和社会关系尚未记录在案。对繁殖季节（2015 年 12 月）监测的 17 个人的无线电遥测数据的分析表明，个体家庭范围的部分重叠很常见，发生在雄性-雌性以及雌性-雌性动物对之间。然而，空间关系是动态的，家庭范围大小和重叠每天都在变化。尽管研究人群的成员不符合通常用于识别生活在地下物种中的群体的标准，但他们并不是完全孤立的。相反，这些动物表现出一种中间形式的社会组织，其特点是不同成年人占据的区域持续部分重叠。