What makes wild chimpanzees wake up at night?

Terrestrial nest-building by wild chimpanzees (Pan troglodytes): Implications for the tree-to-ground sleep transition in early hominins

(2012) Kathelijne Koops et al.   AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY

A Thermodynamic Comparison of Arboreal and Terrestrial Sleeping Sites for Dry-Habitat Chimpanzees (Pan troglodytes schweinfurthii) at the Toro-Semliki Wildlife Reserve, Uganda

(2012) DAVID R. SAMSON et al.   AMERICAN JOURNAL OF PRIMATOLOGY

Environmental Influences on Sleep Behavior in Captive Male Chimpanzees (Pan troglodytes)

(2012) Naruki Morimura et al.   INTERNATIONAL JOURNAL OF PRIMATOLOGY

Brief communication: Why sleep in a nest? empirical testing of the function of simple shelters made by wild chimpanzees

(2011) F.A. Stewart   AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY

Coprophagy-related interspecific nocturnal interactions between Japanese macaques (Macaca fuscata yakui) and sika deer (Cervus nippon yakushimae)

(2010) Mari Nishikawa et al.   PRIMATES

Behaviour and ecology of the wild Patas monkey, Erythrocebus patas, in Uganda

(2009) K. R. L. Hall   JOURNAL OF ZOOLOGY

Sleeping tree choice by Bwindi chimpanzees

(2008) Craig B. Stanford et al.   AMERICAN JOURNAL OF PRIMATOLOGY