Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
Patrick J Tkaczynski
Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire; Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; Department of Human Evolutionary Biology, Harvard University, Cambridge, United States
Pawel Fedurek
Division of Psychology, University of Stirling, Stirling, United Kingdom
Cristina Gomes
Tropical Conservation Institute, Florida International University, Miami, United States
Therese Löhrich
World Wide Fund for Nature, Dzanga Sangha Protected Areas, Bangui, Central African Republic; Robert Koch Institute, Epidemiology of Highly Pathogenic Microorganisms, Berlin, Germany
Virgile Manin
Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
Anna Preis
Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
Prince F Valé
Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire; Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Unité de Formation et de Recherche Biosciences, Université Félix Houphouët Boigny, Abidjan, Côte d'Ivoire
Tobias Deschner
Interim Group Primatology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire; Institut des Sciences Cognitives, CNRS, Lyon, France
The biological embedding model (BEM) suggests that fitness costs of maternal loss arise when early-life experience embeds long-term alterations to hypothalamic-pituitary-adrenal (HPA) axis activity. Alternatively, the adaptive calibration model (ACM) regards physiological changes during ontogeny as short-term adaptations. Both models have been tested in humans but rarely in wild, long-lived animals. We assessed whether, as in humans, maternal loss had short- and long-term impacts on orphan wild chimpanzee urinary cortisol levels and diurnal urinary cortisol slopes, both indicative of HPA axis functioning. Immature chimpanzees recently orphaned and/or orphaned early in life had diurnal cortisol slopes reflecting heightened activation of the HPA axis. However, these effects appeared short-term, with no consistent differences between orphan and non-orphan cortisol profiles in mature males, suggesting stronger support for the ACM than the BEM in wild chimpanzees. Compensatory mechanisms, such as adoption, may buffer against certain physiological effects of maternal loss in this species.
