Wild great apes build beds for sleeping by combining tree branches or other vegetation, but the development of this behavior is poorly understood. We investigated the development of bed-building behaviors by conducting complementary cross-sectional and longitudinal studies of captive chimpanzees. In the cross-sectional study, we created an ethogram of behaviors related to bed-building by observing 59 chimpanzees living at the Kumamoto Sanctuary, Kyoto University, and the Kyoto City Zoo. In the longitudinal study, we installed bed-building platforms, provided branches on the platforms on a regular basis, and recorded behaviors of five chimpanzees (including an infant born in 2013) over a 3-year period from February 2015 to February 2018 at the Kyoto City Zoo (total 490.7 h). We found that all the chimpanzees performed some form of bed-building behavior but wild-born chimpanzees possessed more sophisticated techniques than captive-born chimpanzees. We also found that although the offspring of a wild-born female only showed simple techniques at the beginning of the longitudinal study, his repertoire of bed-building behaviors became as complex as that of his mother by the age of five. Our results suggest that improved bed-building behaviors can be supported in captive-born great apes by providing learning opportunities during appropriate stages of development.

中文翻译：

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圈养黑猩猩（Pan troglodytes）筑床行为的发展：对关键期假设和圈养管理的影响

野生类人猿通过结合树枝或其他植物来建造睡觉的床，但人们对这种行为的发展知之甚少。我们通过对圈养黑猩猩进行互补的横断面和纵向研究来调查筑床行为的发展。在横断面研究中，我们通过观察生活在熊本保护区、京都大学和京都市动物园的 59 只黑猩猩，创建了与铺床相关的行为图谱。在纵向研究中，我们安装了铺床平台，定期在平台上提供树枝，并记录了 2015 年 2 月至 2018 年 2 月 3 年间 5 只黑猩猩（包括 2013 年出生的婴儿）的行为。京都市动物园（共 490.7 小时）。我们发现所有的黑猩猩都表现出某种形式的铺床行为，但野生黑猩猩比圈养黑猩猩拥有更复杂的技术。我们还发现，虽然野生雌性的后代在纵向研究开始时只表现出简单的技术，但他的铺床行为在五岁时变得和母亲一样复杂。我们的研究结果表明，通过在适当的发育阶段提供学习机会，可以改善圈养出生的类人猿的铺床行为。到五岁时，他的铺床行为变得和他母亲一样复杂。我们的研究结果表明，通过在适当的发育阶段提供学习机会，可以改善圈养出生的类人猿的铺床行为。到五岁时，他的铺床行为变得和他母亲一样复杂。我们的研究结果表明，通过在适当的发育阶段提供学习机会，可以改善圈养出生的类人猿的铺床行为。