Nocturnal Primate Research Group, Oxford Brookes University, Oxford, United Kingdom.
Little Fireface Project, Rumah Hijau, Cipaganti, Garut, Indonesia.
Am J Phys Anthropol. 2018 Jul;166(3):563-577. doi: 10.1002/ajpa.23450.
Synthesize information on sleep patterns, sleep site use, and daytime predation at sleep sites in lorisiforms of Asia and Africa (10 genera, 36 species), and infer patterns of evolution of sleep site selection.
We conducted fieldwork in 12 African and six Asian countries, collecting data on sleep sites, timing of sleep and predation during daytime. We obtained additional information from literature and through correspondence. Using a phylogenetic approach, we established ancestral states of sleep site selection in lorisiforms and traced their evolution.
The ancestral lorisiform was a fur-clinger and used dense tangles and branches/forks as sleep sites. Use of tree holes and nests as sleep sites emerged ∼22 Mya (range 17-26 Mya) in Africa, and use of bamboo emerged ∼11 (7-14) Mya in Asia and later in Africa. Fur clinging and some sleep sites (e.g., tree holes, nests, but not bamboo or dense tangles) show strong phylogenetic signal. Nests are used by Galagoides, Paragalago, Galago and Otolemur; tree holes by Galago, Paragalago, Sciurocheirus and Perodicticus; tangles by Nycticebus, Loris, Galagoides, Galago, Euoticus, Otolemur, Perodicticus and Arctocebus; all but Sciurocheirus and Otolemur additionally sleep on branches/forks. Daytime predation may affect sleep site selection and sleep patterns in some species of Nycticebus, Galago, Galagoides, Otolemur and Perodicticus. Most lorisiforms enter their sleep sites around sunrise and leave around sunset; several are active during twilight or, briefly, during daytime.
Variations in sleep behavior, sleep patterns and vulnerability to daytime predation provide a window into the variation that was present in sleep in early primates. Overall, lorisiforms use the daytime for sleeping and no species can be classified as cathemeral or polycyclic.
综合亚洲和非洲（10 属，36 种）懒猴类动物的睡眠模式、睡眠地点使用和白天在睡眠地点捕食的信息，并推断其睡眠地点选择的进化模式。
我们在 12 个非洲国家和 6 个亚洲国家进行了实地考察，收集了有关睡眠地点、白天睡眠时间和捕食的信息。我们从文献和通信中获得了额外的信息。我们采用系统发育方法，确定了懒猴类动物的祖先睡眠地点选择状态，并追溯了其进化历程。
祖先的懒猴类动物是一种缠抱者，使用浓密的纠结和树枝/分叉作为睡眠地点。非洲大约在 2200 万年前（范围在 1700 万至 2600 万年前）出现了树洞和巢穴作为睡眠地点，亚洲大约在 1100 万年前（700 万至 1400 万年前）出现了竹子作为睡眠地点，后来非洲也出现了竹子作为睡眠地点。缠抱和一些睡眠地点（如树洞、巢穴，但不是竹子或浓密的纠结）表现出强烈的系统发育信号。巢穴被 Galagoides、Paragalago、Galago 和 Otolemur 使用；树洞被 Galago、Paragalago、Sciurocheirus 和 Perodicticus 使用；纠结被 Nycticebus、Loris、Galagoides、Galago、Euoticus、Otolemur、Perodicticus 和 Arctocebus 使用；除了 Sciurocheirus 和 Otolemur，所有物种还会在树枝/分叉上睡觉。白天捕食可能会影响某些 Nycticebus、Galago、Galagoides、Otolemur 和 Perodicticus 物种的睡眠地点选择和睡眠模式。大多数懒猴类动物在日出前后进入睡眠地点，在日落前后离开；一些在黄昏时分或白天短暂时间内活动。
睡眠行为、睡眠模式和白天捕食易感性的变化为早期灵长类动物的睡眠变化提供了一个窗口。总体而言，懒猴类动物白天睡觉，没有一种可以被归类为日活动或多周期的物种。
