Department of Anthropology and Primate Molecular Ecology and Evolution Laboratory, The University of Texas at Austin, Austin, Texas, USA.
Department of Anthropology, University of California Davis, Davis, California, USA.
Am J Primatol. 2021 May;83(5):e23225. doi: 10.1002/ajp.23225. Epub 2020 Dec 28.
Patterns of ranging behavior and space use are key for evaluating current ideas about the evolution and maintenance of pair-living and sexual monogamy as they provide insights into the dispersion of females, the potential for territoriality, and whether males are limited to defending an area that can support only one female and her offspring. We examined ranging behavior and space use to evaluate the potential for territoriality in five groups of red titi monkeys (Plecturocebus discolor) during a 10-year study in Ecuadorian Amazonia. Mean home range size, calculated using a time-sensitive local convex hull estimation procedure, was 4.0 ± 1.4 ha. Annual home ranges of neighboring groups overlapped, on average, 0%-7%. Mean daily path length was 670 ± 194 m, resulting in defendability indices of 2.2-3.6 across groups. Groups visited, on average, 4 of 12 sections of their home range border area per day, but that was not more often than would be expected by chance, and intergroup encounters were infrequent. We did not find evidence of active monitoring for intruders in border areas, in that groups did not travel either faster or slower when at the border than when in central areas of their range. The absence of overt monitoring might be compensated for by engaging in loud calls, which the study groups did throughout their home ranges; these calls may serve as an advertisement of occupancy and a deterrent to intruding conspecifics. Our finding that red titis have a high potential for territoriality is consistent with several of the main hypotheses proposed to explain pair-living in mammals.
行为模式和空间利用模式是评估关于对生和性单配制进化和维持的现有观点的关键，因为它们提供了关于雌性扩散、领地性的潜力以及雄性是否仅限于保卫仅能容纳一只雌性及其后代的区域的信息。我们在厄瓜多尔亚马逊地区进行了一项为期 10 年的研究，检查了 5 群红吼猴（Plecturocebus discolor）的行为模式和空间利用情况，以评估其领地性的潜力。使用时间敏感的局部凸壳估计程序计算出的平均家域大小为 4.0±1.4 公顷。相邻群体的年度家域平均重叠 0%-7%。平均每日路径长度为 670±194 米，导致群体的防御指数在 2.2-3.6 之间。群体平均每天访问家域边界区域的 12 个部分中的 4 个，但这并不比随机情况下更频繁，而且群体间的相遇也很少见。我们没有发现在边界区域主动监测入侵者的证据，因为当群体在边界时，它们的行进速度不会比在其家域中心区域时更快或更慢。边界区域没有明显的监测可能是通过发出响亮的叫声来补偿的，研究群体在整个家域中都会发出这些叫声；这些叫声可能是对占据的广告，也是阻止入侵同种个体的威慑。我们发现红吼猴具有很高的领地性潜力，这与解释哺乳动物对生的几个主要假设一致。
