Orangutans have larger gestural repertoires in captivity than in the wild—A case of weak innovation?
Marlen Fröhlich,
Natasha Bartolotta,
Caroline Fryns,
Colin Wagner,
Laurene Momon,
Marvin Jaffrezic,
Tatang Mitra Setia,
Caroline Schuppli,
Maria A. van Noordwijk,
Carel P. van Schaik
Affiliations
Marlen Fröhlich
Department of Anthropology, University of Zurich, 8057 Zurich, Switzerland; Corresponding author
Natasha Bartolotta
Department of Anthropology, University of Zurich, 8057 Zurich, Switzerland
Caroline Fryns
Department of Anthropology, University of Zurich, 8057 Zurich, Switzerland; Institute of Biology, University of Neuchâtel, 2000 Neuchâtel, Switzerland
Colin Wagner
Département Ecologie, Physiologie et Ethologie, University of Strasbourg, 67037 Strasbourg, France
Laurene Momon
Département Ecologie, Physiologie et Ethologie, University of Strasbourg, 67037 Strasbourg, France
Marvin Jaffrezic
Département Ecologie, Physiologie et Ethologie, University of Strasbourg, 67037 Strasbourg, France
Tatang Mitra Setia
Fakultas Biologi, Universitas Nasional, 12520 Jakarta Selatan, Indonesia
Caroline Schuppli
Department of Anthropology, University of Zurich, 8057 Zurich, Switzerland; Development and Evolution of Cognition Research Group, Max Planck Institute of Animal Behavior, 78467 Konstanz, Germany
Maria A. van Noordwijk
Department of Anthropology, University of Zurich, 8057 Zurich, Switzerland; Comparative Socioecology Research Group, Max Planck Institute of Animal Behavior, 78467 Konstanz, Germany
Carel P. van Schaik
Department of Anthropology, University of Zurich, 8057 Zurich, Switzerland; Center for the Interdisciplinary Study of Language Evolution (ISLE), University of Zurich, 8050 Zurich, Switzerland; Comparative Socioecology Research Group, Max Planck Institute of Animal Behavior, 78467 Konstanz, Germany
Summary: Whether nonhuman species can change their communicative repertoire in response to socio-ecological environments has critical implications for communicative innovativeness prior to the emergence of human language, with its unparalleled productivity. Here, we use a comparative sample of wild and zoo-housed orangutans of two species (Pongo abelii, Pongo pygmaeus) to assess the effect of the wild-captive contrast on repertoires of gestures and facial expressions. We find that repertoires on both the individual and population levels are larger in captive than in wild settings, regardless of species, age class, or sampling effort. In the more sociable Sumatran species, dominant use of signals toward single outcomes was also higher in captive settings. We thus conclude that orangutans exposed to more sociable and terrestrial conditions evince behavioral plasticity, in that they produce additional innate or innovated signals that are highly functionally specific. These findings suggest a latent capacity for innovativeness in these apes' communicative repertoires.
