Homosexual behavior in wild Sumatran orangutans (Pongo pygmaeus abelii)


  • Elizabeth A. Fox

    Corresponding author
    1. Wildlife Conservation Society, Bronx, New York
    2. Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey
    • Ecology and Evolutionary Biology, Guyot Hall, Princeton University, Princeton, NJ 08544
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Wild male Sumatran orangutans at two study sites engaged in homosexual behavior. These observations demonstrate that homosexual behavior is not an artifact of captivity or contact with humans. In separate instances, homosexual behavior was associated with affiliative and agonistic behaviors. These observations add orangutans to the list of primates in which homosexual behavior forms part of the natural repertoire of sexual or sociosexual behavior. Am. J. Primatol. 55:177–181, 2001. © 2001 Wiley-Liss, Inc.