New research shows male bonobos use subtle, hidden cues - not just swelling - to track a female’s fertile days with surprising accuracy.

The study measured “rank” within the bonobo communities by tallying how many times females won conflicts with males. Females usually came out on top. Photograph by Christian Ziegler By banding ...

In most mammals, females are only receptive to mating during ovulation, allowing males to time their mating efforts to maximize the chances of conception. But in some primates, such as bonobos (Pan ...