Male Monkeys Eavesdrop on Mating Females

For the most part, the listening males ignored the non-ejaculatory copulation calls, even though they were emitted by a fertile female. When vocalizations associated with ejaculation were played, however, the males looked around and approached the speaker.

The findings have been accepted for publication in the journal Animal Behavior.

While the researches did not conduct the experiment with actual mating couples, they theorize that in the wild, eavesdropping males would be more inclined to mate with a female who has just received another male's sperm. Since sperm itself "competes" within the female for access to her egg, the noisy process may promote competition, result in fertilization by the fittest male and therefore be supported by natural selection.

Stuart Semple, senior lecturer in the School of Human and Life Sciences at London's Roehampton University, studies primate socializing and welfare.

Semple told Discovery News the he thinks the new study presents "very exciting results, which further our understanding of the complex information content and function of female copulation calls," he said.

Semple added, "I would, however, be very hesitant to extrapolate the findings to copulation calling in humans."

Pfefferle agrees on that point.

"The mating system of humans is believed to be different from the one of Barbary macaques," she said.

Related Links:

Jennifer Viegas' blog: Born Animal

Animal Planet

Primate Mating Systems

Barbary Macaque Factsheet