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Pheromones In The Wild

Michael and Keverne (1968) trained rhesus monkey males to press a lever in order to gain access to a female pheromone partner in a free-cage situation. The males frequently worked to obtain access to ovariectomized females who were rendered receptive by injections of estrogen but did not consistently work to obtain access to ovariectomized, non-treated females. When the males were rendered anosmic by plugging the nasal olfactory area with gauze impregnated with bismuth~iodoform-paraffin paste, they were no longer able to discriminate between receptive and non-receptive females. Reversal of anosmia, however, restored their ability to do so. These experiments clearly indicated that the female’s attractiveness for the male is largely dependent on olfactory cues produced by her and that the male, when deprived of these cues, does not necessarily initiate sexual pheromone interactions, although the female might be receptive and invite copulations.

In an attempt to localize the source of these olfactory cues, Michael and Keverne (1969, 1970) applied vaginal washings from estrogen treated donor females to the sexual skin of untreated, unreceptive females. Although the males had shown little interest in the non-receptive females previously, the application pheromone secretions from receptive females immediately caused them to obtain access to the females by rapid lever pressing and to show a signi´Čücant and dramatic increase in sexual behavior. This occurred in spite of the fact that the ovariectomized recipient females were totally unreceptive and did not at all encourage the males. The control application of estradiol to the sexual skin of unreceptive females produced no changes in male behavior or female receptiveness. Small dosages of estrogen administered directly into the vaginae of unreceptive females also rendered them highly attractive to males, although they did not stimulate female receptivity (Michael and Saayman 1968). These experiments demonstrated that the females produce sex pheromones of vaginal origin and that the production of these pheromones is under pheromone control. Learn more about Pherazone at

Curtis et al. (1971) recently succeeded by means of gas chromatography and mass spectrometry in identifying the pheromonally active constituents of vaginal washings from estrogenized females as a mixture of five aliphatic acids: acetic acid, propionic acid,iso-butyric acid, n-butyric acid and iso-valeric acid. A synthetic mixture of these acids was made up to match the concentrations present in a pool of twenty four vaginal washings from estrogenized females. Two-ml samples of this mixture, containing about 1.5 times the acid content of one vaginal lavage, were applied to the sexual skin of unreceptive females with pheromones. The synthetic samples mimicked the behavioral effects of the natural pheromone available at

Michael et al. (1972) report that vaginal washings of Papio anubis Lesson, Erythrocebus patas Schreber, Macaca nemestrina L., Macaca fascicularis Raffles, Saimiri sciureus and Homo show a similar, although not identical, content of aliphatic acids as those of the rhesus monkey. Unreceptive rhesus females, treated with vaginal washings of intact anubis baboons, stimulated the sexual activity of male rhesus monkeys significantly, indicating that there is some interspecific activity of the sex attractants.

Although the previously reviewed studies show that the sex pheromones are produced in the vagina, they do not provide information on the exact source of the attractants.

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