Check out this from the nyt...
Meredith Chivers is a creator of bonobo pornography. She is a 36-year-old psychology professor at Queen’s University in the small city of Kingston, Ontario, a highly regarded scientist and a member of the editorial board of the world’s leading journal of sexual research, Archives of Sexual Behavior. The bonobo film was part of a series of related experiments she has carried out over the past several years. She found footage of bonobos, a species of ape, as they mated, and then, because the accompanying sounds were dull — “bonobos don’t seem to make much noise in sex,” she told me, “though the females give a kind of pleasure grin and make chirpy sounds” — she dubbed in some animated chimpanzee hooting and screeching. She showed the short movie to men and women, straight and gay. To the same subjects, she also showed clips of heterosexual sex, male and female homosexual sex, a man masturbating, a woman masturbating, a chiseled man walking naked on a beach and a well-toned woman doing calisthenics in the nude.
http://www.nytimes.com/2009/01/25/magazine/25desire-t.html?emc=eta1