Nest grouping patterns of bonobos (Pan paniscus) in relation to fruit availability in a forest-savannah mosaic.
A topic of major interest in socio-ecology is the comparison of chimpanzees and bonobos' grouping patterns. Numerous studies have highlighted the impact of social and environmental factors on the different evolution in group cohesion seen in these sister species. We are still lacking, however, key information about bonobo social traits across their habitat range, in order to make accurate inter-species comparisons. In this study we investigated bonobo social cohesiveness at nesting sites depending on fruit availability in the forest-savannah mosaic of western Democratic Republic of Congo (DRC), a bonobo habitat which has received little attention from researchers and is characterized by high food resource variation within years. We collected data on two bonobo communities. Nest counts at nesting sites were used as a proxy for night grouping patterns and were analysed with regard to fruit availability. We also modelled bonobo population density at the site in order to investigate yearly variation. We found that one community density varied across the three years of surveys, suggesting that this bonobo community has significant variability in use of its home range. This finding highlights the importance of forest connectivity, a likely prerequisite for the ability of bonobos to adapt their ranging patterns to fruit availability changes. We found no influence of overall fruit availability on bonobo cohesiveness. Only fruit availability at the nesting sites showed a positive influence, indicating that bonobos favour food 'hot spots' as sleeping sites. Our findings have confirmed the results obtained from previous studies carried out in the dense tropical forests of DRC. Nevertheless, in order to clarify the impact of environmental variability on bonobo social cohesiveness, we will need to make direct observations of the apes in the forest-savannah mosaic as well as make comparisons across the entirety of the bonobos' range using systematic methodology.
Behavioural Biology Unit, University of Liege, Liege, Belgium; Conservation Biology Unit, Royal Belgian Institute of Natural Sciences, Brussels, Belgium; Ecole Régionale Post-Universitaire d'Aménagement et de Gestion Intégrés des Forêts et Territoires Tropicaux, University of Kinshasa, Kinshasa, Democratic Republic of the Congo; Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
Adeline
A
Serckx
Behavioural Biology Unit, University of Liege, Liege, Belgium.
Marie-Claude
MC
Huynen
Ecole Régionale Post-Universitaire d'Aménagement et de Gestion Intégrés des Forêts et Territoires Tropicaux, University of Kinshasa, Kinshasa, Democratic Republic of the Congo; Landscape Ecology and Vegetal Production Systems Unit, Université Libre de Bruxelles, Brussels, Belgium; Biodiversity and Landscape Architecture Unit, Gembloux AgroBio-Tech, University of Liege, Gembloux, Belgium.
Jean-François
JF
Bastin
Behavioural Biology Unit, University of Liege, Liege, Belgium.
Alain
A
Hambuckers
Conservation Biology Unit, Royal Belgian Institute of Natural Sciences, Brussels, Belgium.
Roseline C
RC
Beudels-Jamar
Behavioural Biology Unit, University of Liege, Liege, Belgium.
Marie
M
Vimond
Behavioural Biology Unit, University of Liege, Liege, Belgium.
Emilien
E
Raynaud
Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; German Centre for Integrative Biodiversity Research, Leipzig, Germany.
Hjalmar S
HS
Kühl
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D017753:Ecosystem; D005247:Feeding Behavior / Q000502:physiology*; D065928:Forests; D005638:Fruit; D065948:Grassland; D019974:Pan paniscus / Q000502:physiology*; D012919:Social Behavior