A researcher from the Bronx Zoo-based Wildlife Conservation Society has observed homosexual behavior among orangutans in Sumatra, marking the first time scientists have witnessed this activity among wild populations of these critically endangered great apes. Elizabeth Fox, who has studied orangutans since 1994, published her observations in last month's American Journal of Primatology.
\These observations add orangutans to the list of primates that demonstrate homosexual behavior as part of their natural repertoire of social and sexual behavior,"" Fox said.
During her long-term study of orangutans in Sumatra, Fox observed only four orangutans demonstrating homosexual behavior, which indicates that the behavior is rare. All four were males, two of them sexually mature and two adolescents. Fox also observed the two sexually mature males mate with adult females. Previously, homosexual behavior was only witnessed among captive orangutans or rehabilitated animals that have come in close contact with humans.
