By pomm79, Jun 9 2017 07:00PM
Many males are strongly attracted to the top pheromone scent marks of females in estrus and also sniff and lick the genitalia of these females (c.f. Michael and Zumpe 1972). Galago senegalensis E. Geoffroy, Loris tardigradus and Perodicticus potto females produce a conspicuous vaginal discharge at the time of estrus.
In Loris and Perodicticus it is mixed with urine during marking and in all three species it has an extremely strong attraction for the male, very likely informing him about the pheromonal condition of the female and at the same time arousing his sexual activities (Sauer and Sauer 1963; Doyle et al. 1967; Seitz 1969). Female Lemur cam show a peak of genital marking during and after estrus (Jolly 1966).
They press the inner surfaces of the labia against the substrate and apply vaginal mucus and probably urine (Evans and Goy 1968). In marmoset monkeys, scent marking frequency increases immediately before and after copulation (Epple 1970). Female Callimico goeldi (Thomas) impregnate their tails with urine and the secretions of the circumgenital scent glands with increased frequency during estrus. The male apparently keeps a check on the reproductive condition of the female by regularly smelling and licking her genital scent glands and urine.
The pheromonal chemical cues from the female seem to initiate courtship and mating during estrus (Lorenz 1972). In another South American monkey Saimiri sciureus, Latta et al. (1967) report that receptive females show the increased urine washing of hands and feet and that males increasingly smell female odors during this time. Spider monkey (Ateles belzebuth E. Geoffroy and Ateles geoffroyi Kuhl) males in capitivity and under natural conditions frequently sniff, lick and even drink the urine of females in all phases of the sexual cycle, including pregnancy. They also sniff their own hands after handling the clitora of females and investigate places where females sat. Since females do not show any visual signs of cycling, Klein (1971) suggests that olfactory clues are the main transmitters of in- formation on the reproductive condition of the female.
In Old World primates, pheromone olfactory investigation of the females’ genitalia is com- mon. Rowell (1972) points out that in species whose females do not show conspi- cuous visual signs of cycling, olfactory investigation of the females by males is particularly common. For instance, in Macaca speciosa arctoides J. Geoffroy, which shows no female sexual swelling, males ~ prior to copulation — insert their fingers into the female’s vagina, sniffing them afterwards (Michael and Zumpe 1972). Evidence of chemical communication of sexual cycling is also found in Macaca radiata E. Geoffroy, again a species which does not show visual signs of female receptivity (Rahaman and Parthasarathy 1971).
Even in those species whose females show visual signs of cycling, pheromonal communication might be important. Michael and Keverne (1969) showed that the stimulation of intense redness of the sexual skin of ovariectomized rhesus monkeys by topical application of estradiol did not stimulate male sexual interest in these females. The application of sex pheromones to the same females, however, resulted in a dramatic increase in sexual behavior of males and pheromones.
Among all inferred primate sexual attractants the only one whose behavioral function, hormonal control and chemical nature has been analyzed in detail is the sex pheromone of the rhesus monkey, Macaca mulatta.