title: Early maternal loss affects social integration of chimpanzees throughout their lifetime.
abstract: The long-term effects of early adverse experiences on later psychosocial functioning are well described in humans, but sparsely documented for chimpanzees. In our earlier studies, we investigated the effects of maternal and social deprivation on three groups of ex-laboratory chimpanzees who experienced either an early or later onset of long-term deprivation. Here we expand our research by adding data on subjects that came from two stable zoo groups. The groups comprised of early maternally deprived wild-caught chimpanzees and non-deprived zoo-born chimpanzees. We found that compared to zoo chimpanzees, ex-laboratory chimpanzees were more restricted regarding their association partners in the newly formed groups, but not during their second year of group-life, indicating that social stability has an important influence on the toleration of association partners close-by. Social grooming activity, however, was impaired in early long-term deprived ex-laboratory chimpanzees as well as in early maternally deprived zoo chimpanzees compared to non-deprived zoo chimpanzees. Thus, we conclude that early maternal loss has lifelong effects on the social integration of chimpanzees which becomes evident in their grooming networks. Although the retrospective nature of our study prevents a clear causal explanation, our results are of importance for understanding the development of social competence in chimpanzees.
authors.affiliation: Institute of Zoology, University of Graz, Universitaetsplatz 2, 8010 Graz, Austria.
authors.forename: Elfriede
authors.initials: E
authors.lastname: Kalcher-Sommersguter
authors.affiliation: Competence Center Apes, Four Paws, Linke Wienzeile 236, 1150 Vienna, Austria.
authors.forename: Signe
authors.initials: S
authors.lastname: Preuschoft
authors.affiliation: Institute of Zoology, University of Graz, Universitaetsplatz 2, 8010 Graz, Austria.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Franz-Schaider
authors.affiliation: Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
authors.forename: Charlotte K
authors.initials: CK
authors.lastname: Hemelrijk
authors.affiliation: Institute of Zoology, University of Graz, Universitaetsplatz 2, 8010 Graz, Austria.
authors.forename: Karl
authors.initials: K
authors.lastname: Crailsheim
authors.affiliation: Department of Cognitive Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.|Department of Animal Ecology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors.forename: Jorg J M
authors.initials: JJ
authors.lastname: Massen
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D006120:Grooming; D002679:Pan troglodytes / Q000523:psychology*; D012919:Social Behavior