TY - JOUR
T1 - Nocturnal activity in wild chimpanzees (Pan troglodytes)
T2 - Evidence for flexible sleeping patterns and insights into human evolution
AU - Tagg, Nikki
AU - McCarthy, Maureen
AU - Dieguez, Paula
AU - Bocksberger, Gaëlle
AU - Willie, Jacob
AU - Mundry, Roger
AU - Stewart, Fiona
AU - Arandjelovic, Mimi
AU - Widness, Jane
AU - Landsmann, Anja
AU - Agbor, Anthony
AU - Angedakin, Samuel
AU - Ayimisin, Ayuk Emmanuel
AU - Bessone, Mattia
AU - Brazzola, Gregory
AU - Corogenes, Katherine
AU - Deschner, Tobias
AU - Dilambaka, Emmanuel
AU - Eno-Nku, Manasseh
AU - Eshuis, Henk
AU - Goedmakers, Annemarie
AU - Granjon, Anne Céline
AU - Head, Josephine
AU - Hermans, Veerle
AU - Jones, Sorrel
AU - Kadam, Parag
AU - Kambi, Mohamed
AU - Langergraber, Kevin
AU - Lapeyre, Vincent
AU - Lapuente, Juan
AU - Lee, Kevin
AU - Leinert, Vera
AU - Maretti, Giovanna
AU - Marrocoli, Sergio
AU - Meier, Amelia
AU - Nicholl, Sonia
AU - Normand, Emmanuelle
AU - Ormsby, Lucy Jayne
AU - Piel, Alex
AU - Robinson, Orume
AU - Sommer, Volker
AU - ter Heegde, Martijn
AU - Tickle, Alexander
AU - Ton, Els
AU - van Schijndel, Joost
AU - Vanleeuwe, Hilde
AU - Vergnes, Virginie
AU - Wessling, Erin
AU - Wittig, Roman M.
AU - Zuberbuehler, Klaus
AU - Kuehl, Hjalmar
AU - Boesch, Christophe
N1 - Funding Information:
The authors thank all contributors to the PanAf, including field teams and assistants and logistical staff. For the Bili Project, they thank Cleve Hicks who led the survey mission, and Karsten Dierks who served as the PanAf Team Leader in charge of the camera-trap project. They thank Yasmin Moebius for coordinating the 2010/2011 the PanAf sites and Mizuki Murai for coordinating the 2011/2012 the PanAf sites. Thanks to Sarah Allen, Adam McMaster, Darren McRoy, Chris Snyder, Laura Trouille, and Laura Whyte from the Zooniverse for development and running of the Chimp&See platform, and to the 9,303 volunteers who contributed to Chimp&See classifications and discussions (https:// www.chimpandsee.org/#/about/authors). Thanks to Kristin Havercamp, Joana Pereira, Eva Martinez, and Silke Atmaca for assistance with video coding and organization. Thanks to Caroline Tagg for the initial inspiration for this research, to Nina Flowers for assistance with data extraction and organization, and to two anonymous reviewers and the AJPA team for constructive review of the paper. The authors thank the following organizations who enabled data collection within the relevant countries: Ministère de la Recherche Scientifique et de l’Innovation, Cameroun; Ministère des Forets et de la Faune, Cameroun; Ministère des Eaux et Forets, Cote d’Ivoire; Ministère de l’Enseignement supérieur et de la Recherche scientifique, Cote d’Ivoire; Institut Congo-lais pour la Conservation de la Nature, DRC; Ministère de la Recherche Scientifique, DRC; Agence Nationale des Parcs Nationaux, Gabon; Centre National de la Recherche Scientifique (CENAREST), Gabon; Ministère de l’Agriculture de l’Elevage et des Eaux et Forets, Guinée; Ministério da Agricultura e Desenvolvimento Rural, Guinea Bissau; Instituto da Biodiversidade e das Áreas Protegidas (IBAP), Guinea Bissau; Forestry Development Authority, Liberia; National Park Service, Nigeria; Ministère de l’Economie Forestière, République de Congo; Ministère de la Recherche Scientifique et Technologie, République de Congo; Direction des Eaux, Forets et Chasses, Senegal; Tanzania Commission for Science and Technology, Tanzania; Tanzania Wildlife Research Institute, Tanzania; Uganda National Council for Science and Technology (UNCST), Uganda; Ugandan Wildlife Authority, Uganda.
Publisher Copyright:
© 2018 Wiley Periodicals, Inc.
PY - 2018/7
Y1 - 2018/7
N2 - Objectives: We investigated occurrences and patterns of terrestrial nocturnal activity in wild chimpanzees (Pan troglodytes) and modelled the influence of various ecological predictors on nocturnal activity. Methods: Data were extracted from terrestrial camera-trap footage and ecological surveys from 22 chimpanzee study sites participating in the Pan African Programme: The Cultured Chimpanzee. We described videos demonstrating nocturnal activity, and we tested the effects of the percentage of forest, abundance of predators (lions, leopards and hyenas), abundance of large mammals (buffalos and elephants), average daily temperature, rainfall, human activity, and percent illumination on the probability of nocturnal activity. Results: We found terrestrial nocturnal activity to occur at 18 of the 22 study sites, at an overall average proportion of 1.80% of total chimpanzee activity, and to occur during all hours of the night, but more frequently during twilight hours. We found a higher probability of nocturnal activity with lower levels of human activity, higher average daily temperature, and at sites with a larger percentage of forest. We found no effect of the abundance of predators and large mammals, rainfall, or moon illumination. Discussion: Chimpanzee terrestrial nocturnal activity appears widespread yet infrequent, which suggests a consolidated sleeping pattern. Nocturnal activity may be driven by the stress of high daily temperatures and may be enabled at low levels of human activity. Human activity may exert a relatively greater influence on chimpanzee nocturnal behavior than predator presence. We suggest that chimpanzee nocturnal activity is flexible, enabling them to respond to changing environmental factors.
AB - Objectives: We investigated occurrences and patterns of terrestrial nocturnal activity in wild chimpanzees (Pan troglodytes) and modelled the influence of various ecological predictors on nocturnal activity. Methods: Data were extracted from terrestrial camera-trap footage and ecological surveys from 22 chimpanzee study sites participating in the Pan African Programme: The Cultured Chimpanzee. We described videos demonstrating nocturnal activity, and we tested the effects of the percentage of forest, abundance of predators (lions, leopards and hyenas), abundance of large mammals (buffalos and elephants), average daily temperature, rainfall, human activity, and percent illumination on the probability of nocturnal activity. Results: We found terrestrial nocturnal activity to occur at 18 of the 22 study sites, at an overall average proportion of 1.80% of total chimpanzee activity, and to occur during all hours of the night, but more frequently during twilight hours. We found a higher probability of nocturnal activity with lower levels of human activity, higher average daily temperature, and at sites with a larger percentage of forest. We found no effect of the abundance of predators and large mammals, rainfall, or moon illumination. Discussion: Chimpanzee terrestrial nocturnal activity appears widespread yet infrequent, which suggests a consolidated sleeping pattern. Nocturnal activity may be driven by the stress of high daily temperatures and may be enabled at low levels of human activity. Human activity may exert a relatively greater influence on chimpanzee nocturnal behavior than predator presence. We suggest that chimpanzee nocturnal activity is flexible, enabling them to respond to changing environmental factors.
KW - PanAf
KW - camera trap
KW - chimpanzee
KW - fragmentation
KW - nocturnal awakening
KW - sleeping patterns
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U2 - 10.1002/ajpa.23478
DO - 10.1002/ajpa.23478
M3 - Article
C2 - 29989158
AN - SCOPUS:85049797662
SN - 0002-9483
VL - 166
SP - 510
EP - 529
JO - American journal of physical anthropology
JF - American journal of physical anthropology
IS - 3
ER -