"Many primates, including humans, receive signals from individuals with whom they are familiar," said James Higham, who led the study at the University of Chicago.
"The results... shed new light on the role that experience can play in reading others' mating signals," said Laurie Santos, study co-author and psychologist from Yale University.
Scientists have long been curious about how females of some primate species, including humans, advertise their fertility and how males recognise often subtle signals, the journal Proceedings of the Royal Society B reports.
Previous research has shown that the faces of female monkeys sometimes darken when they are fertile, but not all females show exactly the same changes, according to a Yale statement.
Researchers looked at a rhesus macaque population on the island of Cayo Santiago, off the coast of Puerto Rico, testing whether males could detect when a female was ovulating from her picture alone.
They presented male monkeys with two pictures of the same female's face: one from a day on which she was ovulating, and one from a time before she was ovulating.
More than 80 percent of males from the female's group were able to discriminate between the two faces, looking longer at the photograph in which she was ovulating than the one in which she was pre-fertile.
This result suggests that males may increase their chance of detecting a female's receptivity by getting to know her.
