Many primates show sex differences in behavior, particularly social behavior, but also tool use for extractive foraging. All great apes learn to build a supportive structure for sleep. Whether sex differences exist in building, as in extractive foraging, is unknown, and little is known about how building skills develop and vary between individuals in the wild. We therefore aimed to describe the nesting behavior of savanna chimpanzees (Pan troglodytes verus) in Fongoli, Senegal to provide comparative data and to investigate possible sex or age differences in nest building behaviors and nest characteristics. We followed chimpanzee groups to their night nesting sites to record group (55 nights) and individual level data (17 individuals) on nest building initiation and duration (57 nests) during the dry season between October 2007 and March 2008. We returned the following morning to record nest and tree characteristics (71 nests built by 25 individuals). Fongoli chimpanzees nested later than reported for other great apes, but no sex differences in initiating building emerged. Observations were limited but suggest adult females and immature males to nest higher, in larger trees than adult males, and adult females to take longer to build than either adult or immature males. Smaller females and immature males may avoid predation or access thinner, malleable branches, by nesting higher than adult males. These differences suggest that sex differences described for chimpanzee tool use may extend to nest building, with females investing more time and effort in constructing a safe, warm structure for sleep than males do.

中文翻译：

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性别偏见和社会对稀树草原黑猩猩（Pan troglodytes verus）筑巢行为的影响

许多灵长类动物在行为上表现出性别差异，尤其是社会行为，但也表现出采掘性觅食的工具使用。所有的类人猿都学会为睡眠建立支撑结构。建筑中是否存在性别差异，如采掘性觅食，尚不清楚，而且人们对建筑技能如何发展以及野外个体之间的差异知之甚少。因此，我们旨在描述塞内加尔 Fongoli 的稀树草原黑猩猩（Pan troglodytes verus）的筑巢行为，以提供比较数据并调查筑巢行为和巢穴特征中可能存在的性别或年龄差异。在 2007 年 10 月至 2008 年 3 月的旱季期间，我们跟踪黑猩猩群体到它们的夜间筑巢地点，以记录群体（55 晚）和个体水平（17 只个体）的筑巢开始和持续时间（57 个巢穴）的数据。我们第二天早上回来记录巢穴和树木的特征（25 个人建造了 71 个巢穴）。Fongoli 黑猩猩的筑巢时间比其他类人猿报告的要晚，但在开始建造方面没有出现性别差异。观察是有限的，但表明成年雌性和未成熟雄性比成年雄性在更大的树中筑巢更高，并且成年雌性比成年或未成熟雄性需要更长的时间来建造。较小的雌性和未成熟的雄性可以通过比成年雄性更高的筑巢来避免捕食或接近更细、有延展性的树枝。这些差异表明黑猩猩使用工具的性别差异可能会扩展到筑巢，雌性比雄性投入更多的时间和精力来构建安全、温暖的睡眠结构。